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In the last installment of the driving dynamics blog, we explored the interplay between static mass distribution and power delivery in the Tesla Roadster. That’s a complicated way of saying that we looked at how the Tesla Roadster drives based on two key parameters: its chassis architecture (mid-“engine,” rear wheel drive) and power delivery characteristics (extremely broad, flat torque curve). By way of a quick refresher on the subject, the Tesla Roadster maintains the bulk of its mass, the battery pack, ahead of the rear axle and delivers its power to the rear wheels in a linear fashion.
Now let’s look at some of the further intricacies of weight and driving dynamics.
Without digressing too much, I’d like to tackle a reoccurring question because it dovetails perfectly with a discussion of driving dynamics. “Would four hub-mounted motors have made for a better Tesla Roadster?” In a word: no. Four hub-mounted motors would work great in an electric off road vehicle or rally car – power to each wheel could be controlled for mud, ice, and gravel along with the hill control feature used in off-roading. In a sports car, the added weight and complexity would have compromised the driving enjoyment that makes a sports car a driver’s delight.
Consider the following. When world renowned race car driver and Lotus founder, Colin Chapman, uttered his famous words, “add lightness,” the actual quote was, “simplicate, then add lightness.” His point was this: Do not add anything to the car that would compromise the purity of the driving experience. In designing the Tesla Roadster, the engineers went to great lengths to ensure that the car is, and would remain, a driver’s car. Why use four motors when one would do? All ingredients were to be kept in perfect balance. As innovative and high-tech as the Tesla Roadster is, at its core there has been a philosophy of KISS (Keep It Simple, Stupid).
Further, and this goes back to weight management theory, while weight compromises every aspect of performance from acceleration to braking and handling, different types of weight are more or less problematic in the design of a car.
Rotating Mass
The weight that engineers most worry about is rotating mass. In other words, anything that goes round and round as the car moves. This includes components like the wheels, tires, brake rotors, and even the lug nuts. Besides the gyroscopic forces that a spinning wheel assembly represents as a car turns, this is mass that needs to be spun up to speed for acceleration and slowed back down again for braking. More mass here means relatively slower acceleration and braking.
In designing the Tesla Roadster, the engineers incorporated forged aluminum wheels to help reduce rotating mass while at the same time providing a wheel that would better withstand bending than its cast counterpart. By forging the aluminum under enormous pressure, the molecules are more closely packed and thus it takes less aluminum to make a significantly stronger (and lighter) wheel. In addition, the wheels and tires were sized to provide optimal lateral grip, without any excess beyond what the chassis needs to achieve optimal cornering. A 175 series front tire mounted on a relatively small sixteen inch rim may seem very narrow for a performance car, but this careful scrutiny of tuning the chassis for a specific wheel and tire configuration allowed engineers at Tesla Motors to extract maximum tire grip for spectacular performance without adding flab back into the car. Sure, the engineers could have specified steamroller-sized wheels and tires to put even more rubber on the road and inflate the lateral grip numbers for the magazine statistics. That would have compromised the Tesla Roadster’s tactile response, and created a car that tramlines over grooves in the pavement and thuds over bumps and potholes, but posts amazing dry skid pads numbers. At the end of the day, shouldn’t a car be fun to drive and not simply a way of generating numbers that look good in a magazine, especially if you can hit the high numbers without resorting to caveman tech to do it?
Unsprung Mass
The next concern moving up the weight ladder is unsprung mass. This represents any mass that goes up and down as the suspension compresses and decompresses, for example tires. This includes elements of the rotating mass described above along with the hub assemblies, brake calipers, and suspension control arms. The more weight carried here, the longer it takes the car to regain its composure as it soaks up bumps and variations in the road surface. A car with less unsprung weight will feel lighter on its feet, while an increase in unsprung weight will make the handling feel lethargic and uncommunicative. By the time the driver feels what the car is doing, his or her reaction time will have greatly diminished and the important tactile feedback will have been lost. Here too, the engineers would have been compromising the handling of the car by mounting heavy hub-mounted motors (drastically increasing the unsprung mass) at each of the four corners.
Sprung Mass
In relative terms, the least significant weight is sprung mass, and this includes everything on the car’s body and chassis that is held aloft by the suspension assembly. Even here there are distinctions to be made. Generally speaking, mass above the car’s belt line (the imaginary halfway point that runs horizontally along the perimeter of the car) is more critical than mass below as this affects the center of gravity (how top heavy the car is). The lower the center of gravity, the better from a handling standpoint. This is why engineers go to great lengths in race cars to mount the engines as low as possible in the chassis and using lighter weight alternatives to traditional glass in windows to move the center of mass downwards. In the Tesla Roadster, examples of reduced mass include the optional carbon fiber hardtop (as opposed to heavier alternatives) and the extensive use of carbon fiber body panels on nearly all exterior surfaces (minus the bumpers).
Likewise, weight that is at the polar ends of the car (ahead of the front axle and behind the rear axle) is generally less desirable from a handling standpoint than weight that sits between the axles. Here, too, the Tesla Roadster has short overhangs and carefully managed mass at its extreme ends to help reduce even this form of static mass. The ultimate curb weight of the Tesla Roadster will be among the lightest on the road. In final trim it is expected to weigh on the order of 500 to 1000 pounds less than some of the most esteemed exotics on the market, making the Tesla Roadster a true driver’s delight entirely in line with Colin Chapman’s philosophy. The fact that engineers were able to accomplish an estimated 2,690 curb weight with a 950+ pound battery on board is truly a remarkable feat.
Fluid Mass That Moves
There is also an ingredient not yet addressed in the mass discussion, and that is mass that moves around and changes as the car is driven. Consider the following: In a typical car, a gas tank can hold twenty or more gallons of gasoline. At around 6 pounds a gallon, this represents 120 pounds or more of weight somewhere in the car when full and absent from the car when empty. On a handful of cars, like my MR2, the gas tank is in the middle, so as the gas level drops, the front/rear weight distribution doesn’t change. However, for many cars, the tank is located in the rear and moves the weight distribution forward as the gas is depleted.
Further, the oil – 5-8 quarts on a wet sump system – sloshes in the pan under cornering. At 2 pounds a quart, this adds roughly 10 to 16 pounds of weight that sloshes around. For a dry sump system like a Porsche 911, which holds 24 quarts, this is 48 pounds in oil alone (although in that car, it is spread evenly along the perimeter of the chassis). Other than the obvious point that the Tesla Roadster doesn’t have either a wet or dry sump oil system, since it doesn’t use engine oil, another point worth mentioning here is that the Tesla Roadster will not scavenge or pull air when the pick-up runs dry for either oil or fuel under extreme cornering using sticky tires.
As a side note: in a combustion engine car, the result of pulling air under cornering as the fluid moves around can be a disruptive hiccup under power delivery, all the way to full-fledged engine failure. To date, we have not logged any electron sloshing issues.
The Future of Mass Management
In a car like WhiteStar, Tesla’s forthcoming sports sedan, there is no rule that says that the battery pack needs to be situated in a centralized location. One could imagine a scenario where the bulk of the mass sits lower in the chassis than even the most aggressively prepped race cars with combustion engines. The future looks bright for Tesla’s handling dynamics.
Posted in the categories: Performance, Vehicle Engineering
Isn’t the ESS liquid-cooled? Won’t this cause liquid that can slosh?
# David Vespremi wrote:
## (lots of good points)
Again, I think Tesla made a good decision to bring you on board.
You are are “car guys car guy” at least as far as the kind of sports cars I like to drive.
With the Roadster, the “Elise DNA” made worldclass handling a starting point.
With Whitestar there are so many ways that things could go wrong, so it is assuring to have you there.
## The lower the center of gravity, the better from a handling standpoint.
That is one of the reasons why a lot of “tuner cars” are lowered. (Well it makes them look sort of cool too).
Although you may gain steering feel, and less roll in corners, a typical weekend racer that has been lowered with stiff springs is no fun on a long drive, and can get unsettled by bumps in the road.
## Sure, the engineers could have specified steamroller-sized wheels and tires to put even more rubber on the road
## and inflate the lateral grip numbers for the magazine statistics.
## That would have compromised the Tesla Roadster’s tactile response,
The early autocross/street cars I built up all ended up with one mistake or another. For instance, I had the really wide tires and came to realize that they only belong on a drag car. Also the propensity to make the springs too stiff and/or lower the car too much have happened to a lot of us.
Now days, I appreciate a car that has softer springs, and a reasonable amount of suspension travel yet retains composure and doesn’t roll (much) in the twisties. A really good car handles very well but still has a lot of bump absorbing capabilities. To me the Roadster looks just about right in terms of suspension travel and tire width. It will have to wait until I go for a ride to see just how well the springs are tuned.
## the Tesla Roadster has short overhangs
Well, I hadn’t said anything so far, but to me the front “nose” of the Roadster is a tad too long for my liking.
I have had to force myself to not get hung-up on the desire for a “stub nosed” car look because you really need
that crumple space up front for safety.
Compared to something like the Mini-Cooper (which has almost no overhang), the Tesla has a noticeable amount of bumper and lip in front of the front wheels.
www.carpages.co.uk/mini/mini_images/mini_cooper_s_side_17_08_06.jpg
blogs.chron.com/sciguy/archives/TeslaRoadster.jpg
With that said, the bulk of what is up front on the roadster is very low weight so it really shouldn’t have much bearing on handling.
## In a car like WhiteStar, Tesla’s forthcoming sports sedan, there is no rule that says that the battery pack
## needs to be situated in a centralized location. One could imagine a scenario where the bulk of the mass
## sits lower in the chassis than even the most aggressively prepped race cars with combustion engines.
Aha! A clue as to a potential design decision!
Perhaps we get an “under the floor” battery tray like in the old Rav4EV:
upload.wikimedia.org/wikipedia/en/thumb/f/f3/Rav4evdrawing.jpg/300px-Rav4evdrawing.jpg
# AES wrote on June 12th, 2007 at 5:05 pm
## Isn’t the ESS liquid-cooled? Won’t this cause liquid that can slosh?
I think that is basically a sealed system with little to no air space so there isn’t much sloshing to happen.
Fuel tanks and oil pans tend to have a lot of air space where things can move around.
(Well, the Prius has a fuel “bladder” so perhaps they have a leg up compared to regular fuel tanks in that regard)
Aaargh!!! Those tantilizing tidbits on whitestar leave me craving for more.
##AES wrote on June 12th, 2007 at 5:05 pm
##Isnt the ESS liquid-cooled? Wont this cause liquid that can slosh?
I doubt if there will be any air in the cooling system (thus no room for sloshing).
# David Vespremi wrote:
## …power to each wheel could be controlled for mud, ice, and gravel along with the hill control feature used in off-roading.
## In a sports car, the added weight and complexity would have compromised the driving enjoyment that makes a sports
## car a driver’s delight.
Speaking of AWD in general (not just with EV hub motors) there seems to be some plusses and minuses comparing AWD to RWD.
The mid-rear, ultra-light approach of the Roadster is a winning combination, but it seems that AWD can work in sports/racecars as well.
AWD Sports sedans like Audi S4, and Subaru WRX STI have a loyal following and can show some benefits to having drive traction from the front wheels.
Audi has shown that AWD can work in hard core racing:
oneighturbo.com/category/racing/speed-wc-touring-car/
Then we have AWD supercars like Audi R8, Nissan Skyline, Porsche 966 Turbo AWD, Lamborhini Murcielago AWD, Bugati Veyron, etc.
I just wanted to point out that AWD is not just for offroading, so a larger car (like the Whitestar for example) could possibly benefit (in some ways) from AWD. This is not a suggestion… Just a comment.
Great post David. Thanks for the much anticpated followup. It sounds like you have done your research. I’m in the process of converting my old commuter car into a BEV. I am now convinced I need to take out the back seat and place the batteries in front of the rear axle. I can’t afford a Lion battery pack for the car, so can anyone suggest a suitable/affordable battery type for a brushless DC motor driven EV (a motor suggestion would be appreciated too)? From what I have researched, flooded lead acid batteries seem to be a common choice. I’m shooting for a ~50 mile range.
To AES,
I am no expert, but the ESS coolant probably wouldn’t weight more than a maybe five pounds in total, plus, the coolant is spread out over the entire battery pack; therefore the coolant weight is not only minimal, but also rather well distributed.
Now my comment on the post:
“At its’ core there has been a philosophy of KISS (Keep It Simple, Stupid).”
Ah, yes, simplicity. Wouldn’t it be great if everything was designed to be simple. Simplicity is key to great engineering.
“the engineers would have been compromising the handling of the car by mounting heavy hub-mounted motors (drastically increasing the unsprung mass) at each of the four corners.”
A simple way to understand the quote from the blog is this: Imagine if your body had alot of weight on your hands and feet? It wouldn’t be very easy to run, would it?
Question to the Editor: What materials do you think will be used for the Whitestar?
Doesn’t the transmission use oil too to help reduce friction and wear?
Informative article, that generated the following questions.
Who is the forged wheel supplier?
Is there a specific reason that Tesla uses AP front calipers and Brembo rear calipers?
Would ceramic discs be lighter that steel discs?
Most cars that pull strong G’s when cornering have more than one fuel pump to compensate for the fuel sloshing. They have a “dry sump” system, or a “trap door” system surrounding the oil pick up in the pan on a “wet sump” oiling system.
In the Tesla the electric motor - transmission - differential are transverse mounted, is there as system to control the oil in the transmission from sloshing?
Is the weight distribution 50 / 50 or is the rear heavier?
Does the car have a power steering?
“Isn’t the ESS liquid-cooled? Won’t this cause liquid that can slosh?”
Not if the liquid cooling is in an air tight system, which I’m sure it is. The fluid will stay put… since it can’t compress.
Might as well make my first comment a guess - the cooling system should have a very small amount of air (if any). Therefore not much room for sloshing… I imagine the gearset has some fluid too; other than that just watch what you eat
Jay
AES wrote on June 12th, 2007 at 5:05 pm
> Isn’t the ESS liquid-cooled? Won’t this cause liquid that can slosh?
David probably didn’t mention this fluid because it is common between the two types of cars. Plus, in both cars the coolant isn’t really free to slosh around anywhere, except the overflow tank, and that’s usually minimal.
For a true thoroughbred sports car like this roadster, a mid ship motor and battery mount (the bulk of the 2690 lb) makes a lot of sense and Chapman’s philosophy of “simplicate, then add lightness” is bang on.
However, looking at the niche popularity of the AWD / 4×4 sedans and wagons (read Subaru Outback, Audi Quattro, etc), could one of the directions that Tesla considers after the Whitestar be such a vehicle - keeping a safe distance from pretentious SUVs?
If it does, 4 wheel motors may not be such a bad idea after all - given that it will help reduce the weight of a complicated drivetrain and also that of the two / three differentials. Also, to reduce unsprung weight, one approach could be to not use “in-wheel” motors (like, say the Mitsubishi Colt MIEV), but rather have 4 motors at the 4 corners driving the wheels through drive rods.
Good question, but I’d think that sloshing could only occur if there’s also air in the system, otherwise there’s no where for the liquid to slosh from and to. Cooling systems work very poorly if there is air in the lines (lousy and inconsistent heat transfer), so there shouldn’t be any sloshing of the coolant. Also, the volume of liquid in the cooling system is likely to be measured in quarts, not gallons, i.e. there’s probably not that much of it even if it could slosh.
Fantastic, the more details on handling the better. While going from zero to 60 in 4s is fun, I find that hooking up a few corners really nicely is a much more rewarding driving experience. Which is why I have a 4wd sports sedan, the power delivery and control that you get in corners is fantastic, you have to try one yourself. So I’ve always been concerned about the grip that might be available from the front of the roadster. This explaination goes a long way to addressing my sceptisim, but put it on a race track with an EVO and I’ll be properly impressed.
Regarding unsprung mass; can the up and down motion be captured as energy to improve the vehicle range?
As I understand it, since the ESS cooling is a closed system, there is no air for the liquid to slosh in.
It is very interesting how far the envelope of battery technology can be taken. The usual gripe, however remains: it is expensive, it has a relatively short life, and it is very heavy.
Thus, compared to the usual run-of-the-mill internal combustion engines, the inclination of the buying public is to go for something that is already well-tested and one that can provide years and years of usable service.
But why bother with batteries at all in the first place???
What if there is a configuration that allows for the removal of the battery pack and yet at the same time provide continuous power with the same advantage of not having to use any type of fuel at all? What if the driving range could be extended indefinitely without resorting to expensive and maintenance-dependent batteries? What if we could do away with all of these hassles and just focus on the pleasures that driving engenders?
I am very much interested in knowing if you can re-think your entire concept of powering pollution-free vahicles, not just the “thinking out of the box” sort of thing, but something more fundamental and entirely revolutionary.
I can show how this can be done, that is, if your group will care to take a look.
Roumelle
Maybe not. If the ESS coolant system is completely full of fluid with no vapour spaces then theres really nowhere for the coolant to slosh to.
General question to anyone who’s spent quality time with a lightweight/high performance exotic.
Is there actually a noticeable change in handling or performance between driving with a full tank of gas versus a nearly empty one ?
Given that with an empty tank the cars 100 or so pounds lighter I’d imagine that there’d be measurable changes but I’m just curious as to whether that translates into anything a driver would feel.
Thanks !
AES
The liquid coolant in the ESS is in a closed system - like water in a (UK) domestic heating system. There is no air in there, so it can’t “slosh”. Obviously there has to be a pump to keep it circulating.
You’re comment got me thinking about something else…
It has always been said that F1 racing cars generate so much downforce that they could, in theory, drive upsidedown at high speed along the roof of a tunnel. In practice tunnel roofs are not clear of obstacles nor durable enough to be driven over and the entry/exit requirements would really need specially constructed tunnel sections. Crucially, ICEs do not function if inverted for a significant time. However an electric motor does not care which way up it is.
Obviously this wouldn’t work for the Tesla or with any other road-legal car, for that matter. You would need a very light, single-seater electric sports car and lots of spoilers……
I think I’ve just come up with the next hair-raising stunt for Ian Wright
Can’t wait for “Inverted Nascar”
In relation to unsprung weight David wrote. “Here too, the engineers would have been compromising the handling of the car by mounting heavy hub-mounted motors (drastically increasing the unsprung mass) at each of the four corners.”
I don’t think the 4.4lbs / 2Kg (1.1lbs per wheel) that the Hi-Pa in wheel motors added to the mini’s unsprung weight can be described as drastically increasing the unsprung mass. www.pmlflightlink.com/motors/hipa_faq.html and www.pmlflightlink.com/archive/news_mini.html.
Don’t get me wrong I am a big admirer of the whole Tesla motors philosophy.
Am I right to assume that rotating mass in an ICE would be your cooling fans, belts, pulleys, (pistons to an extent) etc etc also? Does anyone know if that affects this equation enough, in comparison to the electric motor not having as many factors?
Spreading the word in Rhode Island
-LP
A good blog. It won’t silence the “hub nuts”, but some people will see the point.
AES - the ESS cooling system is full and closed, there isn’t any where for the liquid to slosh. Sloshing only occurs in partially full or flexible tanks.
AES wrote on June 12th, 2007 at 5:05 pm
“Isn’t the ESS liquid-cooled? Won’t this cause liquid that can slosh?”
Yes, it is liquid cooled, but compared to the liquid requirements of gasoline and oil, it is trivial in comparison. The real issue here would be the “sloshing” in the reservoir, which would be at most a couple of quarts of liquid. And most liquid cooled engines (nearly everything on the road today for ICEs) also have liquid cooling requirements of a very similar nature. It also does not correlate to issues of acceleration where you slam on the gas pedal and have a sudden need to increase (or even max out) the delivery systems of the various fluids you need in an ICE. Only sustained draw of current would cause substantial heating of the ESS, which is exactly what the coolant system is designed to deal with.
The sudden draw of current for quick acceleration does cause some problems, but those are electrical issues and not coolant or liquid fuel issues. This is a good point of yet another advantage of an electric vehicle over ICEs.
“To date, we have not logged any electron sloshing issues.”
what about electrolyte?
I have the following considerations:
1. Best traction and best control of forces between car and road can be achieved only by having independent torque control of each of 4 wheels in a wide range. This corresponds to having significant power range applied to every wheel separately. This means that it is better to have independent eMotor rotating every wheel.
2. This wheel eMotor better be able to provide maximum traction limit torque at maximum weight load to particular wheel at maximum speed. It means that overall total power of all wheel connected eMotors should be much higher than sustained ESS power. Such an arrangement should provide maximum control of the vehicle for all conditions. Anythind else would be a compromise of some sort. I believe that weight increase of such 4 eMotors versus single eMotor with differential would be negligible versus total mass of the car.
3. Hub eMotors surely increase rotating mass and unsprung mass. But strictly speaking in both cases it is not the mass but inertia moment associated with that mass is significant. In case of rotating mass acceleration impact, rotational kinetic energy etc are all coming from inertia moment of rotating wheel parts. Inertia moment is a sum (integral) of point masses multiplied by square of radius from the axis for the point. So by keeping most of the mass close to the axis problem could be diminished. This is surely not the hub eMotor arrangement directly by some eMotor stretched along the axis is possible.
4. For unsprung mass again typical set up is that wheel assembly is connected to car body somewhat like a pendulum and springs are basically rotating that wheel accembly back and forth like oscillations of pendulum. It is important to increase wheel assembly acceleration for a given spring force to improve car handling. This acceleration again is inversely proportional to inertia moment of wheel assembly against connection joint to car body position. So if a wheel eMotor is located by its center mass in the point of wheel assembly joint to car body minimum increase of inertia moment would be absorbed. This is again very far from just hub motor but keep similar advantages avoiding hub motor disadvantages.
5. It is correct that for a dry conditions on a good road surface traction is so high that loosing traction on couple wheels and having traction subdivided between other two wheels by differential reduces control capabilities for a car in a somewhat unimportant fashion. So you could have single eMotor configuration OK. But this is not the ultimate limit so high end cars would always be challenged from that angle.
6. Bose corporation a year or two ago announced that they developed linear electric motors and overal active suspension system based on them instead of passive suspension with springs. Such active suspension could overcome limitations of high unsprung weight etc in a similar fashion how power steering makes steering force very low. I guess it is expensive but for high end EV may be worth considering.
I believe that the scheme with 4 eMotors in suspension joints I proposed could be most efficient for pure EV even for WhiteStar class. Surely this is just a suggestion of amateur of car design. It may have some hidden issues I do not know about. It would be nice to discuss it if possible.
Personally many people would prefer to have full possible traction at theoretical maximum of every wheel because of ice on the roads in winter and other reasons of slippery road surface in every day life. So 4-wheel drive with deep range of dynamic torque redestribution and high frequency adaptive wheel traction control is highly desirable. I imagine that it would be measuring maximum of traction for every wheel for a particular moment weight load and for a particular surface contact for a wheel with a road. I think it could update it every few milliseconds. With independent eMotors driving each wheel EV control firmware would be able to deliver highest traction forces both for acceleration and braking. As a result it would be possible to deliver best car handling for every road conditions.
“Roger wrote on June 13th, 2007 at 4:33 am
General question to anyone who’s spent quality time with a lightweight/high performance exotic.
Is there actually a noticeable change in handling or performance between driving with a full tank of gas versus a nearly empty one ?
Given that with an empty tank the cars 100 or so pounds lighter I’d imagine that there’d be measurable changes but I’m just curious as to whether that translates into anything a driver would feel.”
Roger - having owned and driven a track-prepped vintage Porsche 911 for a few years, I can answer this one. Our car was a 1971 911 track car that weighed maybe 2250 pounds with half a tank of gas. This is a light car and it feels very light on the track. With a full tank of gas (the car had a 22 gallon tank located in the front boot) the front of the car felt much more planted that with a half tank or near empty tank. The 911s generally have 60% or more of their weight to the rear, so adding weight up front really makes a difference. In fact, in the very early 911s, people would intentionally add weight to the front of the car (sand bags in the boot was a good way to make the car have better traction in poor weather). So on the track, as the gas tank was depleted, front traction noticeably diminshed. I often liked to have a passenger in the car for the same reason - more weight in front, better traction in the corners. Of course adding weight no doubt slowed the car down, but I was already going as fast as I felt comfortable with and was leaving plenty of power on the table. This is one aspect of the roadster that I am really looking forward to - the overall consistency of the driving experience - say on an autocrss track or road course. In a 911 you could actually find yourself going slower into a turn and having more trouble with it as the car lightens; whereas the roadster should feel the same every time (I am intentionally leaving out tire degredation, but you get the point).
NiMH EV wrote
## the Tesla Roadster has short overhangs
# Well, I hadn’t said anything so far, but to me the front “nose” of the Roadster
# is a tad too long for my liking.I have had to force myself to not get hung-up
# on the desire for a “stub nosed” car look because you really need that
# crumple space up front for safety.
I think that Roadster longer nose is there for aerodynamics, not for crumple space. You of course need that crumple space too, but if that nose isn’t for aerodynamics Roadster would have front wheels in very edge of the car.
# Lord_Pancake wrote on June 13th, 2007 at 6:28 am
## Am I right to assume that rotating mass in an ICE would be your cooling fans, belts, pulleys, (pistons to an extent) etc etc also? ## Does anyone know if that affects this equation enough, in comparison to the electric motor not having as many factors?
Fans/belts/pulleys are somewhat incidental. For an ICE the heavy bits are the flywheel, crankshaft, pistons, and valve train (cams/rockers/valves/etc). ICE motors tend to have balance issues as well so they may have counterbalance shafts, or weights on the flywheel to try to keep them from vibrating everything. For manual trans ICE cars (with no torque converter) the flywheel can be a real heavy item. You need to be able to let the clutch out at ~1000rpms without stalling the engine so they add flywheel mass just to allow the average Joe to shift smoothly. Expert manual trans race drivers will use lighter flywheels but they have to match engine revs more carefully and launch off the line with higher RPMs.
This is another beauty of electric motors for EV drivetrains. With 100% torque off the line you don’t need a flywheel or torque converter so you eliminate that big source of weight. You also never need to worry about “slipping the clutch” or matching revs. Hardcore ICE racers may scoff that this makes it “too easy for everyone to drive quick”, but such is progress.
The only real performance shortcoming of the BEVs are the weight of the batteries. Tesla has done everything to make a “featherweight” auto wrapped around a battery box. If someone were to invent some new electricity storage technology (e.g.: “Micro fusion reactor, or ultra-ultra-capacitor bank”) the performance of BEVs would leave the ICEmobiles so far in the dust.
As it is now, the Li-Ion technology is just crossing the point where you can show that (for performance) it is at least on par with gasoline technology, and will soon be better.
Brandon wrote:
“I am now convinced I need to take out the back seat and place the batteries in front of the rear axle.”
For your EV conversion, a good way to know how you want your batteries placed is to put weights in your car where you’d want the batteries. Then, go for a spin and see how your handling feels. This will give you an idea of how your car will handle and where you should place the batteries.
Regarding AWD:
I’m a former mechanic and licensed NASCAR and SCCA driver (Autocross, Road-course racing, and Rally). For those that advocate AWD, I would urge you to read some good books on driving technique and race-car preparation/handling.
When your rear tires are slipping (such as in off-road driving), there is no question that there is a benefit in driving the front wheels as well (when properly engineered). HOWEVER, the downsides of an AWD design are added weight, complexity (both from a manufacturing standpoint and in terms of wear and potential failures), AND it does not add much in terms of performance when the rear tires are working well.
Without going into too much detail (there are books that can cover this much better than the small space I have here), basic physics dictate that an AWD car must accept at least a small amount of understeer or “push”.
Also, think about those front wheels and what they do under power: You accelerate, and the weight of the car shifts to the rear (you’re pushed back in your seat) - this means there is more downward force on the rear tires providing them with more gripping power. The front tires, however, have LESS downward pressure and thus are not optimal for delivering power to the ground (they’ll spin and burn rubber long before the rear tires do). This is why all the top dragsters in the world are rear-wheel drive.
Now think about cornering: A tire can only take so much force before the coefficient of friction is exceeded and it begins to slip. While the limits are different depending upon the direction of the force applied (i.e. cornering versus acceleration/deceleration), we teach it using a concept called the “circle of traction” (a web search will probably turn up some good links). You can use the tire to brake, accelerate, or turn - but trying to do 2 of those at once means that you’re “robbing” some of the available force in one direction to be able to handle forces in another direction (such as turning and applying power at the same time). Since you’re probably going to be accelerating out of turns, a powered front-wheel is robbing the front tire of some cornering ability in order to apply the acceleration force. On a FWD car the front tires have to do ALL the work of accelerating, braking, and turning; and the rear wheels are just along for the ride.
On a RWD car, the “workload” is more evenly balanced among all 4 tires (2 for steering, 2 for power). Look at all of the most successful on-road race-cars and you’ll see that they’re rear-wheel drive. The reason rally-cars are AWD is because of the surface they run on: FWD is better for “pulling” the car straight after a skidding turn, while RWD is best for straight-ahead acceleration; so having both works well. The reason consumer cars are FWD is for manufacturing ease, and for safety reasons: RWD cars can be skidded and spun much more easily, whereas FWD cars tend to just plow straight ahead if you slam the brakes, jam on the gas, or go around a corner too fast… and since most people don’t know how to get a car out of trouble once they get it INTO trouble, the consensus among manufacturers is that making a car plow straight ahead is the safest alternative.
Take care,
–Noel
P.S. I’d rather have 50 lbs of lead in my cockpit than 5 lbs. of extra unsprung wheel-weight. Its THAT severe! Wheel motors are neat devices, but NOT appropriate for ANY decent-handling/sporty car.
A few disconnected notes:
In order to reduce unsprung mass and weight, there have been attempts in the past to locate the brakes “in-board” of the suspension points; How about using in-board” clamping brakes around the drive axles to reduce the inertia and size of the rotating braking area. perhaps now that mechanical technology has been augmented by microcomputer control, this is now worthy of consideration for your upcoming sports sedan.
There is discussion here on the effects of moving liquids on the CG of autos. The effects of moving fifty pounds of weight from one point to another on a car upsets the balance of the car less on heavier autos than light autos. because the ratio of the overall weight to the moving weight is less on the heavier car. it’s a percentage thing.
In 1886 Gottlieb Daimler demonstrated the ICE driven vehicle; followed by Ford, who produced the mass production ICEs starting in the ’20s. I’m appalled at how long we have had to suffer with the complicated ICEs, When you think about it ,what sense does it make to burn chemicals in the atmosphere and assume there are no consequences? what sense does it make to explode chemicals in a cylinder and then spend lots more money to control the explosions and suppress their emissions? What sense does it make to switch over from gasoline to diesel? The only thing that makes sense, now that we have the technology, is an affordable BEV and it will have taken over 100 years to get there.
I wonder if Telsa would consider a mass drawing for a free car when they introduce the sedan?
This seems a good idea move weight off the wheels to in board motors/brakes.
Wheel fixed to suspension CV joint to short driveshaft to CV joint to Electric motor /Brake/Regeneration fixed/bolted to chassis.
Less unsprung weight and as all four motor/driveshafts the same so mass production
lower cost possible.Also could have FWD RWD or AWD as desired.
I think those of us eyeballing the sport sedan want to make a case for AWD because in the everyday realities of commuting on real roads in real rain or real snow it’s just plain fantastic. Plus, in keeping with the theme of making it easy for the un- or lightly trained to use, with AWD it is much easier to get your car to “do the right thing” than either FWD or RWD. Also, many of the performance limitations of conventional AWD systems come from not being able to control the power distribution accurately enough (or at all, generally). As Noel more or less said, you don’t want to apply acceleration power to the front wheels if they’re already at the traction limit due to turning. It would seem that independent wheel motors could completely overcome this issue. With the ability to control torque independently at each wheel, smart computer programming could ensure that every wheel is used to it’s maximum ability and not more so. That would also go a long way to making the car even easier for the un- or lightly trained to use.
Plus, for the same reasons you want RWD for better grip while accelerating, in an EV you want to get the best regeneration while stopping. That implies having motors on BOTH ends of the vehicle, not just one.
But mainly driving out of the ski lot without having to put on chains just rocks!
And even if you didn’t want to go all out for 4 independent wheel motors, one could argue that one motor plus differential at the front and one motor plus differential at the rear would get you most of the benefits without all those complaints about unsprung mass and the like. Especially with a limited slip in the rear.
That would be roughly the equivalent of my WRX or Eclipse GSX since they have open front differentials and lsd type center and rears (depending on options for the lsds, but always open front). Only in the 2 motor electric version you’d have something way better than a center diff, you’d have fully independent control between front and rear.
I talked to a Toyota salesman today who said that he understood that the next generation 2008 Prius Hybrid could be a plug in that went 40-60 miles on a charge. If they could sell that for ~30K, it would have my attention. 90% of the time I only drive 39 miles a day, but I drive 220 miles about 4 times a month with two other passengers.
Now I assume that this odds of this being true are relatively slim, but he did give me a few details of how he thought it would work.
He said there would be an economy or power mode. In power mode the engine would kick on whenever you wanted to accellerate quickly. In economy mode the engine would only switch on when the battery was getting low. Now given their current 8 year 100K warranty on the hybrid parts and 6yr/60K ICE warrantee and their current reliability, this would be a real solution to a lot of people.
Has anyone else heard about this?
# Noel Wade wrote on June 13th, 2007 at 1:35 pm
## Regarding AWD…
Thanks for all that, Noel.
I am mostly in your camp, and I have never owned an AWD sports car, but I do see articles from time to time that suggest that they can be made to behave and offer some advantages. Sure, for a dragster that stands on the rear wheels, why bother?
Sure if your car is always on a flat, dry, smooth asphalt maybe you don’t need it. But real world driving on the street does include rainy days, or even the occasional gravel, oil slick or otherwise uneven surface.
How about this article on the Carrera 4?
www.roadandtrack.com/article.asp?section_id=6&article_id=2595
…”the new C4 understeers less, feels sportier and laps the Nürburgring as quickly as the Carrera 2 despite being 121 lb. heavier. ..”
Lamborghini also builds race worthy street cars, and offers AWD…
www.seriouswheels.com/cars/top-2006-Lamborghini-Murcielago-LP640.htm
“Just like its predecessors, the Murciélago LP640 features permanent four-wheel drive, based on the reliable Lamborghini VT (Viscous Traction) system. The system is self-governing and does not feature any electronic controls. The drive force is usually divided between the front and rear axles in the ratio of 30 to 70. An independent control circuit adjusts the distribution of the drive force depending on dynamic oscillation, weight distribution and the relative friction factor in perfect synchronization with the Visco clutch. In extreme cases, up to 100% of the drive force can be applied to a single axle.”
(The AWD Murciélago reportedly does 0 to 60 in 3.4, so the AWD can’t be hurting it much in a straight line at least)
www.clublexus.com/forums/archive/index.php/t-151157.html
…”Those of you who believe that AWD cars are designed primarily for driving conditions that are less than optimal are greatly misinformed about this marvel of automotive engineering. Don’t confuse AWD with off-road, 4-wheel drive systems. AWD systems simultaneously and continuously “sense” road conditions under each of the four wheels and apply proportionate power as appropriate. In addition to sure-footedness on slippery roads, AWD generally improves/enhances handling and performance. That’s why Audi Quattros were banned from racing circuits in the late `80s (RWD vehicles could not touch them), and why Porsche and Lamborgini now produce vehicles that feature AWD. “…
findarticles.com/p/articles/mi_m3165/is_4_41/ai_n13675707
…”Grip And Grin …
Audi insisted AWD had another advantage: improved handling - even on dry tarmac. The auto maker made its point over the years by dominating several forms of racing, sometimes thrashing 2-wheel-drive competition so emphatically that AWD was banned.
In the real world, engineers and enthusiasts agree AWD usually is superior to either front-wheel drive or rear-wheel-drive in wet, ice and snow, but they debate AWD’s ability to “improve” handling or cornering behavior on dry roads.
Mechatronic technology, until now largely unheralded, advances AWD to a new level of dynamic ability far beyond its reputation as a traction enabler for foul-weather driving.
That technology has a name: torque vectoring. The engineering that enables torque vectoring is not uncharted territory, but a new showcase, the Super Handling All-Wheel Drive (SH-AWD) system that’s standard for Honda Motor Co. Ltd.’s ‘05 Acura RL sedan, has grabbed the attention of driveline and chassis engineers and buyers.
…
Whether in low-traction conditions or in the dry, many who have driven the Acura RL say SH-AWD’s performance adds an eye-opening new dimension for AWD. Toss the RL into a corner and bury the throttle: The aggressive torque transfer between rear wheels creates the driving sensation of a car on rails.
The RL’s torque-vectoring system has auto maker and supplier engineers buzzing. Some debate the technology’s ultimate impact from a volume perspective, but most agree torque-vectoring is a formidable new advance in AWD development.
More telling, perhaps: Almost every auto maker and AWD-connected supplier is actively evaluating torque-vectoring AWD technology.
…etc…”
Subaru makes a big deal about all of their cars being AWD:
www.drivesubaru.com/SubaruDrive-Sum02/AWD-Demystified.asp
www.subaru-global.com/about/awd/physics/index.html
www.subaru-global.com/about/awd/cornering/index.html
…”Conversely, with rear wheel drive and front wheel steering, turning is sharper, but somewhat less stable.
Apply too much throttle in this case, and the car will tend towards oversteering in corners.”…
Power on oversteer isn’t for everyone. I love “fishtailing” (oldschool term for drifitng) a RWD car on a track, but most people are better off not hanging the rear end out in a wet intersection on the way home from school with the kids. The Roadster isn’t a family car, but Whitestar may well be.
# John L wrote on June 13th, 2007 at 4:02 pm
## This seems a good idea move weight off the wheels to in board motors/brakes.
I once did a brake job on an Alfa Romeo Alfetta GT. It had inboard rear disk brakes:
alfetta.ch/alfetta/my2000/restauration/Bilder/PICT1884.jpg
Tesla is trying to use “off the shelf” parts to keep costs down. As a low volume manufacturer the costs of custom parts will be high. “Outboard” disk brakes seem to be the best “proven” technology today.
Mark, the figures for unsprung weight increase with Hi-Pa motors seem to assume complete removal of the braking system in favor of total reliance upon regenerative braking (based on my cursory view of the link you posted). The roadster has both regenerative braking (on a larger motor) and high-performance friction brakes…I assume removing the latter and reducing the former would completely screw its braking performance.
Oh, and the system isn’t nearly as powerful as the roadster’s motor. If you want the same kind of performance, it’ll cost more weight.
Dave P, I’m with you on the 2-motor whitestar! Skyline killer…
It doesn’t work out at this point, of course….it adds a lot to the vehicle cost, and reduces efficiency, for relatively modest performance enhancement. In a decade, with better batteries and a healthy EV market where a dozen models are battling, this will make sense…Subaru will probably do it. But for now these things are pricey enough without doubling up on the drivetrain.
Of course, fantasy aside, I’m not concerned about handling of the more likely, 1-motor 2wd whitestar. After all, they get to put the weight (ess) wherever they want…it’ll have a crazy-low center of gravity and a perfect weight distribution, and that’s a pretty darn good start.
Dave P wrote on June 13th, 2007 at 5:03 pm
# I think those of us eyeballing the sport sedan want to make a case for
# AWD because in the everyday realities of commuting on real roads in
# real rain or real snow it’s just plain fantastic. Plus, in keeping with the
# theme of making it easy for the un- or lightly trained to use, with AWD it
# is much easier to get your car to “do the right thing” than either FWD or
# RWD.
This really depends of the car. AWD usually is easier to handle as long as you are in control of the car. Once the control of the car moves to the car you have much harder time to get control back than with well-behaving RWD. Thing is that once slipping starts to happen it usually involves only rear-wheels with RWD (oversteering). With AWD it might start with all wheels slipping at once and if that happens it is really really hard to gain control of where your car is going.
Of course there are all kinds of TC-systems that makes turning easier, and with EV you might get “turning aid” by regenerative breaking. But that would increase complexity of the car and might actually make driving experience worse.
I have had an car once that was wonderful to drive on winter. It was FWD but when cornering it did oversteer instead of understeer. It also did that like if it were in slow motion. That made it fun to drive. It was only FWD car ever that could do donuts without handbreak assist. It could also go straight line in 45 degree angle for about hundred meters (depends of the weather and the road) whenever I wanted to. Drive from side-window.
I have also driven an RWD that _should_ have had bad case of oversteer but was painfully understeering one. I have no idea why it was like that. Luckily I didn’t have to drive that many times (it had nightmarish handling in every situation).
Advantages of AWD are evident. I do not see much point on debating them but “classic” implementations do have their shortcommings, price not being the only one. They demand additional care, they add additional “oportunities of failure” and not all of them are equivalent. They come with different tradeoffs of complexity, reliability, cost and performance.
Tesla has a very elegant, simple, low volume and low weight motor and transmission. Would it be possible to put two of these motors and transmission into a car, one in front, on in back without mechanical coupling between them? Central differental would be replaced with computer balancing the front/rear power delivery.
In this way AWD could be delivered without much of added complexity.
Anatoly writes:
‘Bose corporation a year or two ago announced that they developed linear electric motors and overal active suspension system based on them instead of passive suspension with springs. Such active suspension could overcome limitations of high unsprung weight etc in a similar fashion how power steering makes steering force very low. I guess it is expensive but for high end EV may be worth considering.’
I wonder if adding the Bose active suspension would greatly diminsh the driving range? I’m thinking that if not, it would be a wonderful addition. I’ve seen some examples of the incredible stability and safety achieved by having an active suspension (recently shown on some new Mercedes vehicles) and couldn’t help but drool over this being a possibility on the Tesla sedan.
I seriously doubt that there are many folks that have real experience with an active suspension, but I know that I’m very impressed and would very much love to have it considered as an option for what is expected to be an incredible vehicle.
# I once did a brake job on an Alfa Romeo Alfetta GT. It had inboard rear disk brakes:
Was that just an english thing? I know that Jaguars had those too. My neighbor builds hot rods for a living and chromed a Jag rear end on one of them. It definitely takes weight away from the wheels and appears to make brake servicing easier, but I never tried to maintain one.
Do the universal joints wear out faster because both the accelleration and braking put strain on them in opposite directions?
I apologize, as this comment is somewhat off topic. However, I wanted to point out to you that your website does not load under firefon on linux (it reloads infinitely). Granted, this is a somewhat small segment of the population, but a friend of mine with a mac said that it does not load under firefox on his mac either. I have not had a chance to check it on firefox on windows, but that represents about 8-9% of the websurfing crowd for a normal website, and I would guess that many forward thinking EV enthusiasts such as myself have firefox and alternative operating systems. Please fix it, as I had to install another web browser just to post this. I would guess that many people are not willing to go to such lengths.
—-
Editor’s Answer: Thanks for the heads up! This will be fixed soon.
Since we’re on the topic of wheel hub motors and how impractical they are for a sports car, you might want to check out this link www.evworld.com/news.cfm?newsid=15408&url , or www.lightningcarcompany.co.uk/ It talks about the Lightning Car Company in England and their high performance Lightning GT electric sports car. Claims 700+ bhp, 0-60 in under 4 seconds, 130+ mph,10 minute recharge time (with appropriate charger), uses Altairnano Nanosafe batteries, 250+ mile range, has 4 Hi-Pa wheel hub motors, and looks great inside and out. They are available for pre-order in Britain, but of course there is no price listed.
It seems that although wheel hub motors may have their challenges (like lithium batteries have theirs), at least somebody out their is taking on the challenge and demonstrating that maybe they’re not so impractical either.
I hope Tesla will keep an open mind to the possibilities of this technology in the future and not become solely focused just on their own proprietary technology (unless warranted of course!). Their are many newer technologies in the pipeline that could make theirs obsolete before too long. Here’s hoping they remain on the cutting edge.
# It seems that although wheel hub motors may have their challenges (like lithium batteries have theirs), at least somebody out their is taking on the challenge and demonstrating that maybe they’re not so impractical either.
I think part of the issue is that they are not legal under the current US laws because they don’t have traditional brakes. Even if as they state there are redundant backups for their wheel motors, that still doesn’t satisfy the letter of the law.
So even if they are the best thing since sliced bread, they can’t come to these shores right now.
# I wrote:
## I once did a brake job on an Alfa Romeo Alfetta GT. It had inboard rear disk brakes
# mark wrote on June 14th, 2007 at 3:35 am
## Was that just an english thing?
Actually the Alfetta is an Italian car.
I think inboard disk brakes were used by a few car where the designers were trying to copy some F1 race technology.
=================================================================================================
Regarding hub motors. Tesla mentioned that one of the bigger obstacles were safety/certification regulations.
As much as we like to hope that Tesla uses the best possible technology for every single facet of their cars, in some cases their options are limited by regulations.
Between the desire to use proven (cost effective) commodity technology, and trying to make a square peg fit a round regulatory hole, they are making some compromises with their designs.
I agree to not have all hub motors for a sports car, but the WhiteStar will not be a sports car. It would be great to have it out perform in every way to the BMW, Lexus, Acura, and Mercedes cars out there. What about having the standard Electric Drive train, but add 2 “Power/Traction Assist” hub motors to the front 2 wheels only? Does anyone think this would compromise the driving dynamics of the car to much for a 4 door luxury sedan?
# David Vespremi wrote:
## When world renowned race car driver and Lotus founder, Colin Chapman…
Yes, Colin seems to be something of the “father of modern lightweight sports car design philosophy”.
Note - he also pushed the concept of inboard disk brakes, and torsion bars instead of springs…
www.hazelnet.org/lotus/
“A Short History Of Lotus Cars”
…
“Type 72 (1970 to 1975)
The most successful Formula One race car ever raced.
The Lotus 72 used variable rate torsion bar springs at both front and rear, front INBOARD disc brakes, the continuation of the wedge aerodynamic bodywork, multiple element rear wing and side radiators. Today nearly every formula car uses these elements introduced by the Lotus 72.
The Lotus 72 won 3 World’s Constructor’s Championships and 2 Driver’s Championships and is the only Formula One race car to have won 20 Grand Prix races.”
==================================================
By the way, some other Elise variants like the vx220 had shorter overhangs than the Tesla, but they don’t have US style 5mph bumper crash tests in England.
www.hazelnet.org/lotus/vx220.jpg
##Pete A. wrote on June 14th, 2007 at 8:44 am
##Since we’re on the topic of wheel hub motors and how impractical they are for a sports car, you might want to check out this link www.evworld.com/news.cfm?newsid=15408&url , or www.lightningcarcompany.co.uk/ It talks about the Lightning Car Company in England and their high performance Lightning GT electric sports car. Claims 700+ bhp, 0-60 in under 4 seconds, 130+ mph,10 minute recharge time (with appropriate charger), uses Altairnano Nanosafe batteries, 250+ mile range, has 4 Hi-Pa wheel hub motors, and looks great inside and out. They are available for pre-order in Britain, but of course there is no price listed.
##It seems that although wheel hub motors may have their challenges (like lithium batteries have theirs), at least somebody out their is taking on the challenge and demonstrating that maybe they’re not so impractical either.
##I hope Tesla will keep an open mind to the possibilities of this technology in the future and not become solely focused just on their own proprietary technology (unless warranted of course!). Their are many newer technologies in the pipeline that could make theirs obsolete before too long. Here’s hoping they remain on the cutting edge.
This car company was discussed briefly in the last blog. I posted the following link which gives price and other specs:
www.greencarcongress.com/2007/06/uk_company_intr.html#more .
Now that we are talking about handling of the car I want to make everybody remember one point of driving the car:
It is _how_ car loses control. Not _when_ car loses control.
It doesn’t matter if it is AWD, FWD or RWD as long as the car warns the driver before losing grip and if/when it loses that grip it does it smoothly. If it does that like *SNAP*! and you are going backwards who cares what kind of setting it has. You are going to crash. If it does that smooothly you have time to react and regain control of the car.
I have driven many kinds of cars with AWD, RWD and FWD of pretty much all possible sizes and all of those can have good or bad handling. It is mainly suspension and tyres that makes the difference. Bad suspension or bad tyres in othervise good car makes car hard to handle.
FWD and RWD are just as good as AWD in normal blacktop road use as long as car tells the driver what is happening. Even in slippery icy road. Buying a sportscar doesn’t make road a racetrack where you must go as fast as you can. Just drive more carefully if it is slippery. Use winter tyres if it is icy.
Things are quite different if there is risk of getting stuck. then AWD is priceless (as long as it is real AWD and not some lightweight useless AWD without differential locking). But that isn’t a place for Roadster-type sportscar. It just isn’t designed for roads where you can get stuck. Small ground clearance and all that.
Colin Chapman at one time had inboard brakes on one version of the Lotus F1 cars.
On any car brakes are a “consumable” inboard brakes make it more expensive to replace the consumable due to the additional labor requirements. To replace the pads is accpetable, to replace the discs becomes an expensive proposition.
The rear differential with inboard brakes and coil over shocks of an older Jaguar is a thing of beauty, and a maintenence nightmare, it looks good chromed and exposed on a hot rod.
Hummer H1 have inboard brakes.
With ceramic discs inboard brake are a moot point to reduce unsprung weight.
Wheel hub motors - imagine a vehicle going through a large puddle of water, and it infiltrates in 1 or 2 of the 4 motors, creating an intermittant problem with 2 of the hub motors cutting out. Customer goes to the dealer “There’s a problem with my car, seems to have a power loss at times, then its OK and gives a slight tug in the steering wheel”.
Yeah, Timo, you’re right about regaining control, but remember that it’s really very hard to get an AWD car out of control in the first place (when it’s been balanced for stability - a lot of that does depend on the car and the torque split, etc.). The situations that can get it out of control are extreme enough you probably couldn’t easily get a RWD or FWD back in control, either. I’ve only managed to get the Eclipse to skid all 4 tires on dry pavement once and I was intentionally trying to do it to see what would happen back when I first got it (it was my first AWD car). It was very hard to do (and it sounded like a multicar pile up on an LA freeway with all tires skreeching around simultaneously
. After a few years with them, I think the easiest way to get AWD cars back into control is to pretend it’s a FWD car, steer into the skid and floor it and hope the back end sliding around doesn’t catch up with you. So, it’s not impossible, but yeah, traditionally it’s much harder than either FWD or RWD to regain control after you’ve lost it. 
But, with the 2 motor computer controlled system, you could detect such out of control situations and simply make the car fall into FWD or RWD mode-whichever the driver prefers, even!). That’s one of the beauties of having no center differential, you can really right a lot of the problems with traditional AWD.
Oh! Even better, it could just sense whatever the driver is doing with the wheel and the skid direction and just apply the appropriate torque to the wheels depending on whereever they’re pointing. It could just as easily bring the wheels up to speed backwards to regain control when the car does a 180. OK, that would be weird, but it illustrates that it’s just not going to be limited by the inability to control forces the way that traditional AWD is limited). In the multiple electric motor world, it’s pretty much guaranteed you’ll be better off than with any kind of single drive system (because it could always just default TO a single drive system if something better can’t be done).
“I have not had a chance to check it on firefox on windows”
Don’t worry, the Tesla Motors website runs on a Windows computer running firefox.
I don’t understand why everyone thinks AWD is so mandatory for WhiteStar;I agree with Tesla that RWD will be better. Allo me to lay down my points:
1. Some of you point out that AWD will be better for rain and snow. Well, since electric cars have so much torque at low RPM, won’t that torque allow for better stability on slippery roads? (I’m just guessing) Also, a good set of tires would be an easier way to improve stability, although perhaps not as effective.
2. How often does that snow and rain really get that bad? And even if the rain and snow are that bad, are you silly enough to go driving in it? (I understand there are exceptions sometimes though)
3. AWD reduces fuel economy, and thus range, by about 10%. For an EV, a 10% reduction in range is a BIG deal for most people
4. A 10% reduction in rage also means a 10% reduction in battery life! Having a battey that’ll last the life of the vehicle is key to selling; plus, batteries are expensive
Since appearently alot of seem hung up on the idea of AWD though, it wouldn’t surprise me if Tesla offered an AWD version of the Whitestar. (Hint, Hint Tesla Motors!)
#warpedone wrote:
##Tesla has a very elegant, simple, low volume and low weight motor and transmission. Would it be possible to put two of these motors and transmission into a car, one in front, on in back without mechanical coupling between them? Central differental would be replaced with computer balancing the front/rear power delivery.
I was thinking about the same thing except using it more along the lines of a Skyline GTR. That is, the vehicle is RWD except when the car’s rear tires lose traction in certain situations. When the rear wheels start to slip the car splits power between the front and rear, becoming AWD. Also, I think you wouldn’t need a transmission in the front as much as a single locked gear for relative low-speed use. After all, if you’re at high speeds and the rear breaks loose I don’t think changing the dynamics of how power is being transferred to the road will help you.
I remember reading how at lower speeds the Tesla is traction limited rather than power limited and can still do 0-60 in ~4 seconds. It makes you wonder what type of numbers it could post if it could use all 4 tires for acceleration.
#Strada Auto Store wrote:
##The rear differential with inboard brakes and coil over shocks of an older Jaguar is a thing of beauty, and a maintenance nightmare
True and true. I think the maintenance nightmare was more of Jaguar engineering than the basic design. I’m working with my father on a ‘67 Jaguar E-Type Coupe restoration and the front suspension torsion bar, rear diff w/ inboad brakes, etc are wonderful when they work but a pain to maintain (because of the way Jaguar designed everything).
Every weekend I help with the restoration I drive by the Tesla headquarters (only a couple blocks away) trying to get a glimse of the roadster. Only seen it once in passing so far…
##Pete A. wrote on June 14th, 2007 at 8:44 am
##Since we’re on the topic of wheel hub motors and how impractical they are for a sports car, you might want to check out this link www.evworld.com/news.cfm?newsid=15408&url , or www.lightningcarcompany.co.uk/
I just checked out their web site, found it pretty lacking from an information stand point. It’s hard to say ‘yes, that’s a great idea’ when they don’t provide very much information. Perhaps I’ve grown too used to Tesla’s willingness to provide so many details. Looks like a nice car to have but at ~$300,000 a pop and questionable importation to the US I’ll stick with rooting for Tesla first and foremost. From everything I’ve seen, Tesla is taking the most professional, logical approach to trying to becoming an automotive mass manufacturer from scratch.
There have been several people wondering if suspension travel could be used to generate electricity in some way. Anatoly brought up the Bose suspension. For those of you who haven’t seen the Bose suspension:
www.bose.com/controller?event=VIEW_STATIC_PAGE_EVENT&url=/learning/project_sound/bose_suspension.jsp
Short description: this suspension uses “towers” (my term, not theirs) in place of the traditional shocks and springs. These towers have linear electric motors in them that control the suspension travel. Sensors anticipate bumps and dips and a central computer actuates the motors to glide up and over bumps and drop down into holes instead of just cushioning the blow like traditional suspensions.
Bose says that when hitting bumps the motors do recapture some of the electricity used (like the Tesla’s regenerative braking). Overall the system uses about the same amount of electricity as running the A/C (also according to Bose).
On to my point. In theory, with a little reworking, you could use traditional springs to support the weight of a vehicle and use a system similar to Bose’s in place of the standard damper (shock absorber). With springs in place, the motors would not have to actuate to maintain suspension position and would be free to simply absorb the energy of the suspension travel. With electronic cockpit-mounted controls, the damping force could be infinitely variable and you could adjust the sportiness of your suspension with a twist of a dial. I know there are already systems in existence that can tackle this last part, but I think the effect in this case would be much different considering the direct electronic control (not electronics controlling a mechanical part like on adjustable shocks). Basically what you are doing here is adjusting the “regen” on the linear motors.
Unfortunately, as mentioned in previous blogs, I think the added weight, complexity, and least of all cost would probably not make this system something that would be feasible to put on the car. I could be wrong, it could be one of those things that would come down drastically in cost as it is mass-produced (Li-Ion batteries anyone?) and the weight gain may be negligible, but I am not an engineer or corporate cost-cutter. I think someone should build it for a feasibility study (cough, Tesla).
#Joseph wrote on June 14th, 2007 at 7:11 pm
#I don’t understand why everyone thinks AWD is so mandatory
# for WhiteStar;I agree with Tesla that RWD will be better. Allo me
# to lay down my points:
#1. Some of you point out that AWD will be better for rain and snow.
# Well, since electric cars have so much torque at low RPM, won’t that
# torque allow for better stability on slippery roads? (I’m just guessing)
Not really. But AWD isn’t much better to handle then RWD or FWD either in those conditions. I don’t know where that “AWD is way superior in wet/snow” comes from. If you are going too fast and lose grip because of it it happens at pretty much same speed in all of those settings. I haven’t noticed any difference in speed-related control losing moment in any of the settings. Regaining control is different to all of those settings. If the control is lost because power then there is big difference between AWD and RWD/FWD.
# Also, a good set of tires would be an easier way to improve stability,
# although perhaps not as effective.
Definitely. Bad tyres = bad handling. But because this is comparision it doesn’t matter, you can have good set of tyres in all of those settings.
# 2. How often does that snow and rain really get that bad? And even
# if the rain and snow are that bad, are you silly enough to go driving
# in it? (I understand there are exceptions sometimes though)
For Roadster, no. For Whitestar rain, snow or small meteorites shouldn’t stop you from driving. I live in Finland and here winter is always white. During my military time I served in Lapland. AWD would help a lot to drive Whitestar there in small roads. You just couldn’t drive Roadster there, it would get stuck from the bottom.
# 3. AWD reduces fuel economy, and thus range, by about 10%.
# For an EV, a 10% reduction in range is a BIG deal for most people
# 4. A 10% reduction in rage also means a 10% reduction in battery life!
# Having a battey that’ll last the life of the vehicle is key to selling; plus,
# batteries are expensive
That 10% is because gasoline car uses single engine for all wheels and lose some power for increased weight, transmission and power delivery in all of those tyres. This would not be the case for EV. In fact I believe with hub-motors efficiency would actually increase if it is AWD in compared to RWD.
# Since appearently alot of seem hung up on the idea of AWD though,
# it wouldn’t surprise me if Tesla offered an AWD version of the Whitestar.
# (Hint, Hint Tesla Motors!)
I agree that AWD would be nice for Whitestar.
This blog post from Vespremi appears to be reactionary to the Lightning: www.lightningcarcompany.com/
When you are converting cars then someone can always come along and convert something better.
Speaking of White Star Sedan - why don’t you design a Dark Star Coupe based on the same chassis. BMW has a two door and four door 3 series. Audi has the 5 series 2 door and the 6 series four door. In other words - recoup your r & d budget by doubling the potential market. By the way - I hope the design is sleek, clean, muscular european design like the Bentley GT. Please don’t get on the chunky retro bandwagon of the Chrysler 300 or the overly complex swoopy designs of Mercedes.
The discussion of a central motor compared to wheel-hub motors is very interesting— I think Tesla engineers are working plenty hard re-inventing the automobile, without piling on the tasks of re-inventing the wheel, too. In the real world of driving around bumpy corners fast, the tires and wheels are already plenty heavy enough to compromise perfomance–(maybe 30 lbs each?). but it’s gotta be hard knowing that the primary risk is that every gram of weight removed might be piled on the fragility side of the scale.
I’m curious about the balance between regenerative braking and the friction pads/ rotors. It seems the friction system is there primarily for emergency stops, and most of the time wouldn’t be used- seems like a lot of unsprung weight to not even be used in normal driving! But in order to provide adequate braking and safety, the alternative would be to significantly increase the size of the regen system– and if you lived at the top of the hill, there’d be no way to stop with a full battery. Even with 4s 0-60 accel times, braking occurs more quickly- which means that torque would need to be transmitted back to the re-gen system over just a couple seconds, requiring beefier and heavier designs for axles and mounting points. There’s likely some annoying almost-obsolete regulation that requires actual friction brakes…..
It’s very interesting to be able to read the blogs of the Tesla’s path from concept to production!
#
Timo wrote on June 14th, 2007 at 12:52 pm
…
FWD and RWD are just as good as AWD in normal blacktop road use as long as car tells the driver what is happening. Even in slippery icy road. Buying a sportscar doesn’t make road a racetrack where you must go as fast as you can. Just drive more carefully if it is slippery. Use winter tyres if it is icy.
Timo I agree that buying a sportscar doesn’t make the road a racetrack but I disagree that RWD is just as good as FWD or AWD on slippery icy roads. I live in Colorado in an area with some pretty steep hills and reasonable snowfall during the winters. A RWD vehicle is much less productive on snow/ice covered hills even with studded snow tires. I own both and for the most part our FWD does great but there are still times where the 4WD is needed just to get up my driveway. I wouldn’t dream of asking for AWD on the Roadster it sounds to me they have the driving dynamics pegged but for the Whitestar I would really like to see a car I can trust on the icy hills.
Also, the idea in driving on snow and ice is to NOT lose control in the first place. Having AWD and driving responsibly goes a long way to that end.
BTW - I am still real skeptical about hub motors does anyone know how they respond in mountain driving? It’s not the uphill acceleration that I am worried about it’s the downhill part. Would they have the same tendency to overheat and burnout as conventional brakes with the inexperienced driver?
————-
Joseph wrote on June 14th, 2007 at 7:11 pm
I don’t understand why everyone thinks AWD is so mandatory for WhiteStar;I agree with Tesla that RWD will be better. Allo me to lay down my points:
1. Some of you point out that AWD will be better for rain and snow. Well, since electric cars have so much torque at low RPM, won’t that torque allow for better stability on slippery roads? (I’m just guessing) Also, a good set of tires would be an easier way to improve stability, although perhaps not as effective.
A Mustang is a RWD with very high torque. Have you every tried to get one of them up a snow covered hill? High torque is not necessarily an asset on snow and ice.
A nice setup might be an all in one ESS/PEM/eMotor/Brake drive unit.
A low/flat battery box that goes under the car that includes 4 motors (one at each corner of the box).
You could use “hub motors” like the PML flightlink but mount them “inboard” rather than in the wheels.
While you are at it just put a small disc brake right on the output shaft of each motor, then run half shafts to the wheels.
Benefits:
* All the mass as low and centralized as possible.
* Less unsprung weight as the wheels don’t have any eMotor or brake discs to move around.
* No brake dust on your shiny wheels.
* No brake heat on your tires.
www.dannygatton.com/Graphics/StreetRods/Danny_coupe/rear_jag_72dpi.jpg
www.atv.info/images/Site05/articles/227/Inboard%20Disc%20Brakes_tif.jpg
I think you should at least go to England and check out that Mini from PLM Flightlink. Maybe they figured out something you asumed was too complex. Just like all the other car companies dismissed the idea of using 6000 laptop cells as way too complex, dagerous, and too many connections to fail. Don’t close yourself to new posibilities ….
Several people have pointed out that FWD cars have traction advantages over RWD cars in wet or icy conditions. In many cases this is true, but it is not directly because of the FWD layout, it is due to the majority of the weight being on the drive axle. Electric cars do not have to have so much weight in the front of the car. I would not be surprised if the Whitestar had its weight evenly distributed or even slightly rear-biased like many mid-engine sports cars. Remember, what is considered common knowledge about cars does not automatically translate to electric cars.
Jean wrote
# Timo I agree that buying a sportscar doesn’t make the road a
# racetrack but I disagree that RWD is just as good as FWD or
# AWD on slippery icy roads. I live in Colorado in an area with some
# pretty steep hills and reasonable snowfall during the winters. A
# RWD vehicle is much less productive on snow/ice covered hills
# even with studded snow tires.
RWD:s are usually light at the rear-end. That is why they don’t behave that well in snow. If you have weight in rear wheels then it can be quite good, but it still uses front end of the car to push thru snow if there is lots of it. But that isn’t really handling of the car, it is just how well it behaves in bad conditions. Any RWD tractor would beat any AWD family sedan in those conditions.
# I own both and for the most part our
# FWD does great but there are still times where the 4WD is needed
# just to get up my driveway.
It is pretty obvious that in that case AWD is much better than either RWD or FWD. Climbing a icy road is related to case where you can get stuck. If all wheels do work to keep on going it will go further than any car with “dead” tyres.
Don’t get me wrong. I love AWD cars just because with those you can drive in places where similar two-wheel drive cars cannot dream going. Especially if it is build as off-road car. In fact the “car” I fell in love was one military offroad vehicle. It could swim, go full throttle in swamps or deep snow and climb hills more than 50 degree steep (in dry forest floor). Too bad it also used about one liter of gasoline in one kilometer, was very noisy, about 2.5 meters high, 2 meters wide and about 7 meters long and was quite slow in road use.
But that really isn’t something I call “handling”. Any civilian car would beat it in road use.
Although I feel this topic is being beaten to death, I guess I should throw in my ‘druthers as well. I fully understand and agree with every design decision Tesla has made for the Roadster. While things could have gone other ways and my personal preferences might have been otherwise, the most important thing for the Roadster to do is to dominate the requirements of a performance sports car that many people will be willing to pay a lot of money for. I feel they are doing an outstanding job of this.
For the Whitestar, the market will be much different since it is a more mainstream car and its buyers will likely be looking for some utility value rather than raw performance and handling.
Since I live on the side of a mountain, I very much want good controllable regenerative braking so I can avoid brake wear and so that I can recapture all the potential energy I store by climbing the mountain every evening. Clearly, a lot of regenerative braking drag on a rear-wheel vehicle such as the Roadster is a dangerous thing since the rear wheels could easily lock up and that might be very bad. Regen on a FWD, like the EV1 and today’s hybrids, isn’t so invasive since most braking is done by the front brakes anyway. The idea of AWD sounds attractive (although I drove for years in snow country on FWD and RWD vehicles -sans traction control - and never had much trouble gettting anywhere in the snow) and I suppose that All-wheel regenerative braking could be set up for optimal usage.
For Jean: There should be no problem with overheaing while regenerative braking as there is with normal friction brakes. Regenerative braking is similiiar to downshifting of a manual transmission vehicle except that you charge the battery as an added bonus.
Perhaps, similiar to the Toyota Highlander Hybrid AWD, Tesla should optimize the Whitestar design to be a FWD vehicle and later offer an option to add another motor (or 2) to the rear wheels to give AWD capability.
I’ll be happy to let Tesla’s engineers do the real analysis and testing as to the benefits of hub motors -vs- suspended motors and driveshafts to find the best solution(s). They are in a position to actually make informed tests and decisions about this stuff. If they do the design tradeoffs as well for the Whitestar as they appear to be doing on the Roadster, I’m sure the final product will be fantastic and we’ll all love it as much as we do the Roadster.
Go Tesla
Dan - One minor point: FWD stability in rain/snow is also due to the drive wheels being in front of the CG of the car. To use an odd (but accurate analogy), you’re “pulling on a rope” as opposed to trying to push it.
For everyone talking about hub motors: You can get hot and bothered all you want about how cool they are - but have you THOUGHT about the mechanical complexity that a hub motor entails? Think about what the hub motor needs and needs to do, and if you spend 5 or 10 minutes actually writing down the things that come to mind, you can compile quite a long list in a short time! And you want 4 of them? And its not just the weight or complexity of the hub motor - its also the upgraded structural elements (like bearings), too! What about the steering wheels? You want to have to engineer a steering system that can easily and reliably twist and turn all of that weight (which is going to be rotating and thus acting like a big ol’ gyroscope that doesn’t WANT to be turned)? How about in an accident when the wheel becomes disconnected from the axle - now you have a LOT more weight flying down the freeway and smacking into other cars, causing potential death and destruction. Oh, and your total power output gets reduced to the maximum power of each small hub motor can output. Oh, and the idea that AWD Hub Motors saves energy is a fallacy. Remember thermodynamics! You’re going to have efficiency losses whenever you convert energy into motion. You have friction and heat and all kinds of other things - and by moving from one motor to 4 you are quadrupling the places in which you have those efficiency losses… The only thing you gain in that realm by moving to hub motors is the lack of a transmission and differential. But of course you also add wire and connectors and other places to lose power efficiency while you work out a way to route power from the ESS to each motor… And those extra wires also increase the hazard for rescue personnel in an accident situation.
…And I haven’t even BEGUN to talk about failure modes of individual hub motors (how would you like it if 1 wheel motor broke and “locked up” while the other 3 were providing power?).
Hub motors are a cool concept, but for marginal (and questionable) gains you’re talking about dramatically increasing weight, complexity, engineering problems, energy-demands, etc. There are just too many “cons” at this point to outweigh the small “pros” that they offer.
Oh, one final note: Moving the brakes on ANY car inboard helps by moving the rotating mass closer to the CG of the car - but as long as the brakes are attached to the axles they’re STILL unsprung weight; because they’re not being suspended by the springs/struts!
I’m glad to see so much enthusiasm and excitement for the Tesla line of cars (especially since I want them to sell well enough that I can own one someday) - but please remember that they have to consider the engineering realities of their projects. They’re smart people who are already showing that they know how to be original and come up with innovative solutions. Give them credit for the intelligence we KNOW they have, and trust that they’ve done their homework on things like hub motors. If they say they can’t use them, then they have ruled them out for very good and very practical reasons.
NiMH EV, that is a great suggestion and the nice thing about using PML flightlink inboard is that you would not even need any breaks, 100% regen like on their mini. Their approach looks really nice actually.
# Bill C wrote on June 15th, 2007 at 9:19 am
## I’m curious about the balance between regenerative braking and the friction pads/ rotors.
## It seems the friction system is there primarily for emergency stops,… there’d be no way to stop with a full battery.
Some regen systems include a “when full” resistor to absorb excess electricity. So if the batteries are full you just heat up a big resistor instead.
Some had asked why the Roadster (apparently) has different brakes in front than rear.
I heard that the Roadster gets an aftermarket “big brake kit” because it weighs more than the Elise.
The rears are probably already OK because they have the benefit of the regen to go with the existing discs, but the fronts don’t have any regen so they need full disc action during hard braking.
AC propulsion talks about exceptional pad life on their test cars, so the regen must take care of a good portion of the slowing task.
www.acpropulsion.com/reports/Living%20with%20an%20EV.pdf
“An added benefit of effective regenerative braking is reduction in brake wear.
At 85,000 km, the original equipment front brake pads were less than 30% worn.
This wear rate will yield pad life of over 280,000 km (175,000 mi), essentially the life of the vehicle.”
Wired slideshow new today “Green Speed Demons and Other Alternative Autos”:
www.wired.com/cars/futuretransport/multimedia/2007/06/gallery_future_engines?slide=1&slideView=1
Here is my two cent concept for reducing mass. I always wondered how well using a hybird RIM process (super duper mmc/polymer/composite material here) to make composite wheels combined with non-pneumaticd tire system (michelin prototype), plus hybrid RIM the whole chassis, rotor shaft, drive train components,ess case, seats. It would be an interesting concept to proto and test. hmm…think bucky fiber, silicon carbide aluminum fiber, carbon fiber, and peek and a dash of dp460ns heheheh. No kissing here, just pure brain spoking.
Tanx, xlnt blog..
still saving!!
Pete wrote,
“NiMH EV, that is a great suggestion and the nice thing about using PML flightlink inboard is that you would not even need any brakes, 100% regen like on their mini. Their approach looks really nice actually.”
An EV’s ability to utilize regenerative braking (as far as I know) is based on two things:
1. The size of the motor, and this the amount of energy that can be regenerated.
2. The rate at which the battery can accept the charge the motor is regenerating
Let me give an example. ProEV’s Electric Imp has two AC motors that provide regenerative braking. The motors create 200 amps at I don’t know how many volts. They could regenerate more power, but the batteries cannot accept such a fast charging rate. Now, if they had something like AltairNano batteries that can accept fast charges then they’d be able to regenerate more power. But they can’t, so friction brakes are also used. Now, under normal conditions friction brakes are RARELY used, but are sometimes need in an emergency stop or in racing.
So, there are two ways in which PML’s MINI does not have brakes. Either they do not use friction brakes, even though they should for safe stopping distance; or PML is using batteries that accept a very fast rate of charge.
while hub motors sound like a neat idea, a lot of comments on this post raise real issues with them. Additionally, I can’t see it making sense to put this expensive component in an area of the car that suffers the most abuse.
I don’t recall if this was mentioned somewhere, but what is the Roadster strategy for rear wheel traction control?
A traditional sports car may have a limited slip differential that starts to transfer torque from a slipping wheel to the one that still has traction.
I don’t think the Roadster has a limit slip differential. Does electronic traction control negate the need for the limit slip differential?
AES asked this question way back on July 25th, 2006, but I don’t recall seeing an answer.
Typically if electronic controls are used, the ABS system will apply the brakes to a slipping wheel which does force more torque over to the other wheel, but it puts some wear on the brakes and wastes some power as heat.
One benefit of “hub motors” is that they can cut their own power if there are wheel spin concerns.
Normally this is an infrequent concern, but a car like the Roadster seems like one where the driver may frequently request possibly tire slipping acceleration forces.
Traction control on the power wheels (rear) usually works by applying the brake on the wheel that is slipping (losing traction), this can alternate from one wheel to the other with varying degrees of brake application. If the driver insists (very slippery conditions) the traction control will flash a warning and shut down the engine. In slippery conditions traction control works best at lower speeds.
For performance applications (the smoky burnouts) in most cases the traction control is deactivated, there is a switch to deactivate the traction control, and the cars can even go in “dyno mode” to deactivate traction and stability program to allow sideways slides (drifts). A car with traction and stability activated does not do “doughnuts”.
Most cars with 500HP the traction control comes on instantly, and temporarily shuts down the engine, its not a fast way to accelerate. By deactivating the traction control and wihtout a “limited slip” there is the possiblity of spinning only 1 rear wheel, or not drifting as easely. Even F1 cars have one form or another of a “limited slip” differential.
On a high performance car (lots of power) it should have traction and stability for daily driving, and the ability to deactivate both (electronic nannies) for a “spririted white knuckle time”.
# Joseph wrote on June 15th, 2007 at 9:29 pm
## So, there are two ways in which PML’s MINI does not have brakes.
## Either they do not use friction brakes, even though they should for safe
## stopping distance; or PML is using batteries that accept a very fast rate of charge.
I already mentioned what they actually do:
www.pmlflightlink.com/motors/hipa_drive.html
…”Built in brake resistor (for full charge regeneration situations)”…
IMHO, the biggest hurdle against hub motors right now is regulatory.
“or PML is using batteries that accept a very fast rate of charge.”
Or, they simply route the extra power that they cant dump to batteries, into a big fat resistor where it turns to heat as in normal friction brakes. There is no fundamental need for mechanical friction brakes, nor high charge batteries. If you get too much power from motors while braking, you can always just connect a heating coil or resistor.
An emergency lock brake would be a big fat copper bar across the motor coil leads.
I was lucky enough to see the Roadster again today at the Beverly Hills car show. There was a tremendous amount of positive interest in the car — even people who all-but whipped out their checkbooks to buy. A couple of points I was able to glean from the reps:
1) The initial Whitestar renderings are done (but not public, of course). The design is said to have a bit of both Teutonic and English influence, which might make it look like a cross between a BMW and an Aston-Martin — which is to say, it looks like a car.
2) The expected behavior of the Roadster while pointed uphill at a stoplight is to roll backwards, similar to a stick shift. Or at least that’s what the current version does.
3) Roadster range statistics at given speeds (e.g., how far at 50 MPH) are being worked out and tested in real world conditions (thanks, in part, to questions from the blog). The numbers will probably be well above 200 miles.
4) Current orders are over 500. If you order now, you probably won’t see a car within a year, and probably much longer.
5) If battery pack capacity increases, Tesla will likely make those available to owners who want to substitute the newer pack for the original. The replacement may require a software upgrade, but non-battery hardware enhancements probably won’t be necessary.
Just a quick note to say that I found myself flanking one of the AC Propulsion Scion eBox conversions on Hwy 280 in San Jose earlier today. I must give it its props: the eBox was zipping right along, keeping up with aggressive Silicon Valley traffic, and in fact pulled ahead of me and left me behind at one point. I may have been doing, ahem, better than the speed limit at the time, so the eBox was doing even better than that.
Someday, it will be a gorgeous Roadster in the lane next to me, instead of the hideous eBox (which, my passengers simultaneously declared, was perhaps the ugliest car they had ever seen).
Here’s a Tesla video that I haven’t seen yet.
www.prospermag.com/prosper/junespecial/video.htm?u=http://www.prospermag.com/prosper/junespecial/media/tesla_640×480_lg.flv
Strada Auto Store wrote
# On a high performance car (lots of power) it should have traction
# and stability for daily driving, and the ability to deactivate both
# (electronic nannies) for a “spririted white knuckle time”.
If you look at Roadster interior pictures you see there a telltale button “TC”.
So yes. Roadster has TC and it can be deactivated. I don’t have a clue which kind of TC it has, but because all other things have been made well in it I assume that this has been made well too.
The Smart for Two, Smart USA Distributor LLC, has been taking reservations now for several months. The cost is $100.00.
I am quite sure this a simple way to check interest. I would love to see Tesla take reservations on the White Star, say for a
$1,000.00 to $5,000.00. I think numbers like this would seperate the men from the boys. I am ready to place my order.
Is this a “Tesla Authorized” poster, or some knock-off? :
cgi.ebay.com/Red-Tesla-Roadster-Electric-Car-Poster_W0QQitemZ130121198530QQihZ003QQcategoryZ66465QQrdZ1QQssPageNameZWD1VQQcmdZViewItem
Their listing says the Roadster does 0-60 in 3.6…
To flabby: I read in Car Magazine online that the Lightning will sell for £150,000 ($300,000). If that’s anywhere near right they won’t be selling many in England or anywhere else! Much as I would love us Brits to come up with a real competitor for the Tesla I haven’t seen anything yet that makes me feel that we have. I’m sure Tesla’s approach is the right one and of course they’ll adapt to better battery technology once it has been proven and tested. A usable electric sports car for a third of the price of a Lightning is a pretty halibut good start in my opinion. If you want to compete with the big boys you have to think it through and develop the car properly before you launch it. Tesla seems to be doing just that with all its cold weather running and crash testing. The Lightning looks more like a concept car to me that’s way behind the Tesla in terms of actually coming to the market.
TIMO I agree with your tractor comment
If Tesla keeps true to their current ideals of making cars for people who like to drive I don’t believe 2 vs. 4 wheel drive is going to keep me from purchasing a Whitestar.
Earl, thanks for the information.
Editor! Nice touch on the home page, I like the rotating display. What is the reservation count up to these days?
Well, this is certainly getting off topic from the initial blog. But, it’s all good!
I like Tesla’s roadster. But, like all 2 seat “midshippers” it doesn’t score very high on the practicality meter, no matter how fantastically it handles. Which is fine for it’s market segment. I hope they sell a lot of them!
But it would seem that adding something like AWD gives you a lot more versatility for a relatively small amount of extra cost (compared to the battery 
. It would seem to be a much better value proposition to me. For example, if Whitestar were to cost $50k, would you spend $55k to get an awd version? I certainly would. Saves me from having to buy an entirely additional car with AWD for the few times I actually would need it.
For something like Whitestar, I think many of us are trying to make the case for a car with as much practicality and performance as we can get yet at a price we can somehow afford.
Frankly, the battery systems seem to be expensive enough I don’t know if I could afford the battery strapped to some wheels.
Also, for those wondering if electric motors can work effectively as brakes, there are applications successfully using magnetic braking systems, now. I know the Drop Zone uses magnetic brakes for nearly all it’s braking. Can’t find too much information about the systems being used in roller coaster rides and the like, though. I think it’s being used because it’s smoother and requires less maintenance than traditional friction brakes. These industries seem to be satisfied with the reliability and operation of magnetic braking, at least in general.
But many cars already have completely separate parking brake systems, so it would not be unusual.
One link I found: www.velocitymagnetics.com/
Unfortunately, you probably can’t get by with just magnetic brakes on a car. While stopping, sure they recapture power and if your batteries are full you can always get maximum stopping power by effectively shorting them, anyway, but once the rotation actually stops, you need to then apply power to actually provide further “holding” torque. This means you would be capturing power until you actually stopped, then you’d need to expend it to keep you stopped (if you’re not on a flat surface, obviously
You wouldn’t really want to use magnetics as your parking brake for hills…
Yeah! I’m going to second that one. Nice work on the homepage editor! Those photo’s are very captivating. Actually I enjoyed them that much so to place one on my myspace
. Hey what’s the status of your online store?
# Bob Gardner wrote on June 18th, 2007 at 4:41 am
# The Smart for Two, Smart USA Distributor LLC, has been taking reservations now for several months. The cost is $100.00.
# I am quite sure this a simple way to check interest. I would love to see Tesla take reservations on the White Star, say for a
# $1,000.00 to $5,000.00. I think numbers like this would seperate the men from the boys. I am ready to place my order.
While this is a good idea, I anticipate they will ask for a reservation payment of about $20,000 around a year prior to it’s delivery. A small reservation payment now would only be useful if it is agreed that there will be a larger reservation payment later.
NiMH EV wrote on June 18th, 2007 at 6:56 am
# Is this a “Tesla Authorized” poster, or some knock-off? :
#cgi.ebay.com/Red-Tesla-Roadster-Electric-Car-Poster_W0QQitemZ130121198530QQihZ003QQcategoryZ66465QQrdZ1QQssPageNameZWD1VQQcmdZViewItem
Looks like a wallpaper from download-page.
www.teslamotors.com/learn_more/wallpaper.php
Someone has made an poster from it and is now selling it in eBay.
flabby wrote on June 17th, 2007 at 11:37 pm
# Here’s a Tesla video that I haven’t seen yet.
Nice video. This is better than any previous video, you can actually hear the engine whizzling and there are many great shots. There is one silver-colored Roadster in about 45 seconds before end of the film. That looks cool. Better than red or black ones. At least in that backround.
There is one shot with hood open. Since engine is into back and battery is into middle I don’t know what is all that stuff in front. Battery cooling system?
Great link Flabby. Thanks for posting it.
# Timo wrote on June 18th, 2007 at 3:12 pm
## There is one silver-colored Roadster in about 45 seconds before end of the film.
That is an original prototype “test mule”. You may notice it has different wheels. It isn’t even a fully designed Roadster.
## There is one shot with hood open. Since engine is into back and battery is into middle I don’t know what is all that stuff in front. Battery cooling system?
Yes, and the radiator for the air conditioning system as well.
“Since engine is into back and battery is into middle I don’t know what is all that stuff in front”
From the video it looks like the front of the car has some electronic systems along with the cooling systems in front. But my question is this: If you have the battery, motor, and major electronics in the back, then up front there is very little weight; isn’t it best to have have somewhere around a 50/50 weight distribution?
I know that a 40/60 weight distribution is good to since it allows for a car without power-steering, but I mean pretty much the whole car is in the back, from the info provided and my assumptions it seems like weight distribution would be (this is a wild guess though) more like 30/70!
By the way, has anyone seen this video? It’s an EV1 with a mini jet engine in it! How the guy got an EV1 or if he did it before they were crushed, I don’t know. there’s 4 different videos of the car; there’s a video from the interior that shows the battery guage, so it looks like the car is still electric. I guess it’s a plug-in hybrid then!
—-
Editor’s Comment: I see no video. Please post it and I will update this entry.
Joseph -
Don’t underestimate just how much stuff is required for a modern car… You have electronics, vehicle cooling (ESS and such), environmental components (heating and air-conditioning), possibly a spare tire (don’t know where they keep one - if they keep one; but many mid-engine cars put the spare under the hood), the steering system, the front suspension & brake systems, and more.
Plenty of things to weigh down the car with! Plus, if you look at the profile of the vehicle you’ll see a longer front overhang than in the rear - so that lets them “cantilever” the front weight out on a longer moment-arm.
I don’t know about the idea of 60/40 weight splits being ideal. My Miata had darn near 50/50 and was amazingly fun to drive (and surprisingly fast on the track). Remember that weight effectively shifts to the rear under acceleration, so you don’t *need* extra weight on the rear wheels when at rest; and too little weight on the front wheels means that under acceleration you have less front-end grip and therefore less steering authority when giving the car some gas. I know the Tesla is a street-car, but a proper “racing line” has you accelerating from the apex of a corner through to the exit (while still turning). The fastest way around a track maximizes the speed and length of each straightaway - and that requires a fast exit speed from each corner. If you lose too much front-end grip under acceleration, you’ll slide to the outside of the corner and have to back off, resulting in a slower exit-speed from each corner…
I’m willing to bet the Tesla guys have made sure this car has the best weight-bias they can give it - ESPECIALLY given its Lotus heritage.
Timo,
Thanks for the direction to the TC button behind the shifter on the console. Just noticed that the A/C controls are on the console in front of the shifter, its a manual A/C system.
Under the hood there’s a vacuum brake booster, which means that the Roadster must have a vacuum pump for the brake system. The radiator with the 2 electric fans must be for the water that cools the ESS, there should be another radiator for the A/C somewhere.
# Joseph wrote on June 18th, 2007 at 5:25 pm
## If you have the battery, motor, and major electronics in the back,
## then up front there is very little weight; isn’t it best to have have somewhere
## around a 50/50 weight distribution?
www.thetruthaboutcars.com/?p=3383
“…Tesla says that although the Roadster’s batteries add 25 percent to the weight of the elongated Elise; the weight distribution is still 40 - 60 front to rear….”
50/50 is an admirable goal, but I think that is rather unusual for a mid engined car.
Tesla: 40/60
Ferrari: 43/57 (F360)
Boxster: 46/54
Some front engined cars stretch the hood and move the engine back (front/mid) to get to 50/50:
Honda S2000: 50/50
Mazda Rx7 gen3: 50/50
# Joseph wrote on June 18th, 2007 at 5:32 pm
## By the way, has anyone seen an EV1 with a mini jet engine in it!
ev1-club.power.net/archive/990220/ejet.htm
www.youtube.com/watch?v=eaQLbx-opMA
www.youtube.com/watch?v=_lT0VGya43s
www.youtube.com/watch?v=cmmPofUlpSc
www.youtube.com/watch?v=xVxHa_7MKgE
Crazy! (But I think the vids may be from 1999)
You can find the VIN history here:
ev1-club.power.net/vin.htm
(Search for ejet)
Yesterday, as mentioned above, I was found myself driving side-by-side with an AC Propulsion eBox, and it left me in the dust. Today, I was doing my usual run on Ocean Street in Santa Cruz, and what should appear at my side but one of those ZENN cars. I was driving a larger vehicle than usual, and so the ZENN looked even TINIER by comparison! Although I was only doing between 30-35, today was the opposite of yesterday: I left the electric in the dust. But the little thing sure was cute. I got a pretty good look at it for a block or two.
C’mon Tesla! Drive a Roadster on the streets of Santa Cruz! Or down the El Camino in Sunnyvale! I’m tired of encountering all those lesser vehicles (including the occasional Lotus Elise)!
Timo wrote Tesla poster on e-bay: Unreal he makes a buck before Tesla Motors does. lol
I’ve read all of this talk about the importance of handling and performance as built into the Roadster, and I understand some of the design decisions. I am curious, however, about the performance of the Roadster and how it performs (presuming some Tesla folks who have the opportunity want to comment here) on mountain roads or very twisty highways like the Pacific Coast Highway in California (California Highway 1).
As an owner of an SUV who has driven onto roads that are barely recognizable as even being roads in the first place, there definitely is a role for vehicles which have 4WD (AWD?) and I’ve even had to used the “underdrive” gears of my vehicle in practical situations where the extra torque was absolutely necessary even though speed wasn’t really the issue.
All this said, that same vehicle driving up a smooth 2-lane highway going up a mountain canyon getting to those kind of roads in the first place is where the SUV is entirely the wrong kind of vehicle in the first place. By necessity, an SUV is deliberately top heavy (and thankful for it when I slam down on top of rocks and grateful for the 1/2″ thick steel plate protecting the oil pan in the process), has a much larger proportion of its weigh as both rotating mass (for the 4WD), and unsprung mass as well. For off road use, it is a real fun vehicle in its own way, but it is all too easy to flip the vehicle over when cruising around a mountain at 45 MPH facing a completely opposite cardinal direction in less than a minute. Just in time to turn back to the original direction in the next minute.
I’ve seen plenty of wreckage of even Semi-truck trailers who have had drivers clueless about mountain roads and went just a tad bit too fast (the speed limit signs really mean something on these roads!), but in the case of most Sports cars, they tend to “hug” the road much better and can deal with these conditions much better than most other vehicles…. especially when the weather conditions are sunny, dry, and temperate.
I am grateful that Mr. Vespremi has taken the time to explain some of these ideas, and it makes me want to take the Roadster for a spin up the canyons. I’m also hoping that the Whitestar keeps many of these similar design goals, where the experience with the Roadster is going to have a positive long term impression on the rest of the Tesla vehicle line.
So the Roadster is up to 500 cars sold in less than a year. That is a milestone worth noting.
Indeed there were people pulling out checkbooks at the last few Roaster show events. For those that ponied up in person they did a little weekend-sliding on Friday’s price increase.
The result of the flurry was that they have sold 10 percent of their cars just last week. More tha 50 cars!
Pretty good for a car that;
Has never advertised.
Has unproven (by consumers) technology.
Is a luxury car.
More than a fifth put down 100 percent of $100,000.00.
Almost no one has driven.
Few have ridden in.
Some buyers have never actually seen.
Is not from a known major automotive manufacturer.
Has not had significant major automotive press. (VP 10, a silver car should be going out to auto press for quick looks late July, Aug.)
Congats!
I’m sorry Editor! (What a mysterious name!) I forgot to put the video itself! Can you put my post on the bottom so that it doesn’t just wash away with the dozens of posts?
youtube.com/watch?v=eaQLbx-opMA
Robert Horning wrote:
I’ve seen plenty of wreckage of even Semi-truck trailers who have had drivers clueless about mountain roads and went just a tad bit too fast (the speed limit signs really mean something on these roads!), but in the case of most Sports cars, they tend to “hug” the road much better and can deal with these conditions much better than most other vehicles…. especially when the weather conditions are sunny, dry, and temperate.
With that in mind… Mr. Vespremi I have the perfect race for the Roadster. The Pikes Peak International Hill Climb ( www.ppihc.com ) is the second oldest automobile race in the country, only takes about 15 minutes to complete, and is a course of only 12.4 miles. The Roadster would have a distinct advantage over the ICE vehicles since the race covers about 5K ft. of vertical gain and ends at 14,110 ft elevation.
# Jean wrote on June 19th, 2007 at 12:50 pm
## Pikes Peak International Hill Climb ( www.ppihc.com )
## The Roadster would have a distinct advantage over the ICE vehicles…
FYI:
“Electric Pikes Peak Race Car Sets World Record”
www.megawattmotorworks.com/display.asp?dismode=article&artid=36
# “Electric Pikes Peak Race Car Sets World Record”
If you looked more closely you would see that this electric car took almost 50% longer than the fastest car which was close to beating the 10 minute mark.
This isn’t to say that an electric car like the Tesla wouldn’t do better since it doesn’t care about altitude and has torque always available.
# mark wrote on June 19th, 2007 at 3:30 pm
## If you looked more closely you would see that this electric car took almost 50% longer than the fastest car which was close to beating the 10 minute mark.
## This isn’t to say that an electric car like the Tesla wouldn’t do better since it doesn’t care about altitude and has torque always available.
Well the fastest cars tend to be turbocharged which helps an ICE deal with high altitude.
Also the fastest cars tend to have 4WD, extreme ground effects and chassis customization to deal with the difficult dirt terrain.
So, I don’t think the Roadster (out of the box) would be able to take the record.
These are examples of the fastest vehicles that climbed the peak:
www.weismann.net/millen.html
www.rallyracingnews.com/pikes-97.html
As always, another excellent and informative blog entry on Tesla’s part.
On the video that flabby posted, the display screen is shown that has battery state, temperature, etc. On the energy usage screen, it listed a little over 400W/mile. Was this number just higher because it was the last instantaneous power, or perhaps because of the agressive driving that was being done during the demonstration?
In answer to the statement that inboard brakes are unsprung: it depends on where the swing point is; if the brake is inboard of the swing point on the axle its sprung and not unsprung. Additionally, I suggest an engineering exercise to study the idea of a clamp braking system around the axle instead of the common heavy rotor/pad system. I believe if the Regen braking is creatively used, the brakes need not be as heavy duty.
As you all know when a car turns, the inside wheel travels less distance than the outside tire. How does Telsa handle this with one e motor in the back? Do they use limited slip, a Detroit locker, what? The common differential has always been a danger because once one wheel slips, like in snow and ice, traction is lost at the other wheel
I fully understand the difficulties of bringing a radically new car to market and I don’t expect Telsa to go off into left field with engineering studies right-away. Perhaps braking studies are a thing for the future when the company is pushing GM for the most cars sold title.
NiMH EV wrote on June 19th, 2007 at 5:34 pm
Well the fastest cars tend to be turbocharged which helps an ICE deal with high altitude.
Also the fastest cars tend to have 4WD, extreme ground effects and chassis customization to deal with the difficult dirt terrain.
—
Alas, the remainder of the dirt road is scheduled to be paved over by the end of the year. The conservation groups won out regarding erosion on the mountain and the remaining dirt portion of the road is supposed to be paved.
I think they could take one of the VPs once full production is underway and convert it to a racer (or not) and let one of the Unsers drive it in exhibition mode. I still think it would be a good race to show off the Roadster and get some well deserved publicity.
Thanks also for the link!
# Isaac Ladson wrote on June 20th, 2007 at 12:28 am
## How does Telsa handle this with one e motor in the back? Do they use limited slip, a Detroit locker, what?
## The common differential has always been a danger because once one wheel slips, like in snow and ice, traction is lost at the other wheel
Many modern cars just use a non locking diff and then use electronic controls (tied into ABS) to apply braking force to any drive wheel that starts to slip. It puts some wear on your brakes, but it allows you to use a more simple differential.
I haven’t gotten confirmation what Tesla does, but I am guessing that may be doing it this way. I didn’t see limited slip differential advertised as a feature.
Jean wrote on June 20th, 2007 at 8:44 am
## I think they could take one of the VPs once full production is underway and convert it to a racer (or not)
## and let one of the Unsers drive it in exhibition mode.
Unsers, like Hell! Put Danica Patrick or Milka Duno behind the wheel if you want to stir up a little press.
Hey guys. Check out this recent interview video of Elon Musk:
abclocal.go.com/kgo/story?section=global_warm&id=5399716
Interesting… says him and Martin will drive the VPs for 2 months before they produce any customer cars, so as to make sure they’re absolutely perfect. He also states a 0-60 time of 3.9 seconds… wonder if they’ve done some official testing on that and are now confident they’ll beat 4 seconds. Hopefully we get a new blog update soon…
Eric wrote:
“On the energy usage screen, it listed a little over 400W/mile. Was this number just higher because it was the last instantaneous power, or perhaps because of the agressive driving that was being done during the demonstration?”
When Tesla Motors shows off their roadster to customers, do you think they’ll drive it normally, or do you think they’ll do 0-60 sprints and the such? I’m pretty sure Tesla Motors drives their Roadster hard! Every single video I’ve seen of the Tesla Roadster is of it racing across roads. I’d assume that Tesla Motors doesn’t do much “real-life driving” on their Roadster. i.e. traffic, clogged highways and precious little room. Also, Tesla Motors says that ~250 mile range would be greatly decreased with spritied driving, leaving me to assume that they do alot of spirited driving! Plus, I don’t think physics permits for the tiny roadster to consume 400w/h mile!
#hideous eBox (which, my passengers simultaneously declared, was perhaps the ugliest car they had ever seen)
Ouch. Uglier than an Aztek, even?
Seriously though, in defense of the eBox (and the Toyota on which it’s based), although it may not appeal to your aesthetic sense, it’s a fantastically practical vehicle. The Toyotas were designed for the Japanese market, where compact, efficient, and practical generally trump curvy space-wasting designs. If you think good function is the ultimate expression of form, the xB is a nice little package. (If not, then forget about it.)
eBoxes are:
- only a few hundred pounds heavier and $30K cheaper than a Roadster
- approximately as efficient in terms of AC watthours per mile
- a full meter shorter than a typical mid-size sedan
- able to seat 5 large adults plus baggage
- actually available today
NVIDIA has unveiled Tesla Computing Solutions: www.nvidia.com/object/tesla_computing_solutions.html
Yay for brand dilution.
#O. Emry wrote on June 20th, 2007 at 7:32 pm
##hideous eBox (which, my passengers simultaneously declared,
##was perhaps the ugliest car they had ever seen)
#Ouch. Uglier than an Aztek, even?
Before that moment on I-280, I must admit, they had deemed the Aztek the ugliest of contemporary vehicles.
But seriously, how does the xB’s boxy design allow the eBox to be comparable in fuel efficiency to something like the sleek Tesla? Since when is the box an aerodynamically superior design? Perhaps the eBox and Tesla are roughly equivalent at lower speeds. But much above 50MPH, I’d think the eBox’s energy consumption would spike, further and faster than the Roadster’s would. And believe me, the eBox I saw the other day was doing WELL above 50! Maybe close to 80!
Japanese lithium-ion EV extravaganza:
www.youtube.com/profile_videos?user=moiragov
about 20 video clips of EVUK reporters visit to Eco Car World 2007.
Subaru R1E, Mitsubishi MiEV and others are demoed.
Theres the competition for Whitestar
An article in the Chicago Tribune states the reason for the bump in the Roadsters price is due to the weakening dollar with respect to the British pound (i.e. the Lotus parts cost more). It doesn’t say much else new.
Did anyone else notice the last blog from Darryl Siry was “disappeared?”
What is the story there?
Pete
—-
Editor’s Answer: It is still there ….
#Before that moment on I-280, I must admit, they had deemed
#the Aztek the ugliest of contemporary vehicles.
How did you manage to avoid seeing a Scion xB until then? They’ve been available in the states for four years.
#But seriously, how does the xB’s boxy design allow the eBox
#to be comparable in fuel efficiency to something like the sleek Tesla?
Sounds like a question for Tesla. The bottom line is that many (most?) EVs are amazingly efficient, and the reasons aren’t always intuitive.
As an engineer at AC Propulsion, I can tell you that an eBox gets about 250 DC watthours/mile overall, and maybe 280 Wh/mile at highway speed. If Tesla’s ESS stores 56kWh and carries the vehicle 200 miles, that works out about the same.
#But much above 50MPH, I’d think the eBox’s energy consumption would spike,
#further and faster than the Roadster’s would.
I can see why you would think that, but it would be more correct to say energy comsumption “rises gradually” instead of “spikes”. Obviously the Toyota’s boxy shape isn’t designed to be aerodynamic, but as you can see, the differences in air drag don’t lend themselves well to speculation, and probably aren’t all that significant in the end.
#And believe me, the eBox I saw the other day was doing
#WELL above 50! Maybe close to 80!
Yeah, that was probably me.
What you have created at Tesla Motors is a symphony of engineering brilliance. I am awestruck at the beauty and performance of the Tesla Roadster. You have redefined the American sports car. I wish your company the best in its endeavors. I have no doubt your name will soon be synonymous with the names like Lamborghini, Ferrari, and Porsche. Bravo for being pioneers in the automobile industry.
Sincerely,
Terry Montague
Marketing Major
Boise State University
Boise, Idaho
Editor! Where’s the new Blog?
—-
Editor’s Vague Answer: It’s coming.
ZF’s new torque verctoring rear axle:
www.motorauthority.com/news/technical/zf-creates-new-torque-vectoring-rear-axle-for-bmw/
(Appropriate for Whitestar?)
## TEG2 wrote on June 21st, 2007 at 7:17 pm
## ZF’s new torque verctoring rear axle:
[snip]
## (Appropriate for Whitestar?)
Uhm… is this the same TEG that has been posting all along? I’m not an engineer or even a mechanic, I don’t even play one on TV. But I can see that it’s (a) large and complex and (b) just large. Both run against Tesla’s design philosophy. Besides, an EV’s unique need to run power back to the motor for slowing and braking almost demands an entirely custom drive train.
#SRB wrote:
##Hey guys. Check out this recent interview video of Elon Musk:
##abclocal.go.com/kgo/story?section=global_warm&id=5399716
Wow great interview. Elon gives alot of let ons about the future company plans. He states that the WhiteStar will be in the 55k range, with more interior room and much more cargo space than the 5 series BMW. (The current BMW has 14cubic feet of trunk space.)
I am very excited about the Roadsters improved 0-60 time of 3.9s from a previous of 4.2s. I dont know of anything faster under 100k!
Mike B wrote
# I am very excited about the Roadsters improved 0-60 time
# of 3.9s from a previous of 4.2s. I dont know of anything faster
# under 100k!
www.arielmotor.co.uk/04/frames.htm
Here you go.
Not quite as luxurous as Tesla Roadster though
I’m sure this is more than just a bit random and I’m not aware of what would be a more proper place to vent my excitement so you”ll have to excuse my need to squeal like a little school girl. I had to say that everyone here has completely and totally made my day. I don’t care if you don’t actually have anything to do with the creation or production of this vehicle. You’re simply in the right place at the right time. Thank you. Thank you for having the ingenuity and sheer nerve to do what no one else has done. All I can think to say now is “its about #$@! time.”
~Leo
# Mike B wrote on June 22nd, 2007 at 11:50 am
## I am very excited about the Roadsters improved 0-60 time of 3.9s
## I don’t know of anything faster under 100k!
Well, there are some:
Dodge Viper SRT10 ( ~$80K)
Corvette Z06 (~$65K)
www.theautochannel.com/news/2005/06/13/124590.html
But, they are gas guzzlers.
# Mark Tomlinson wrote on June 22nd, 2007 at 11:29 am
## Uhm… is this the same TEG that has been posting all along?
Yep, thats me. I had a slight identity crisis as my initials became ambiguous on the blog.
I tried out using “NiMH EV” as my “blog handle”, but I am back (as TEG2) by popular demand.
## But I can see that it’s large and complex.
Well, yes, it does appear that way, but “Torque Vectoring” appears to be a bit of an automotive rage right now. Sometimes a little bit of size and weight is worth it for the benefits. Anyways, here are some related articles even if it turns out to be inappropriate for WhiteStar:
www.autoindustry.co.uk/news/14-06-07_15
findarticles.com/p/articles/mi_m0KJI/is_3_119/ai_n18770110
>> TEG2 wrote on June 22nd, 2007 at 6:59 pm
>> I tried out using “NiMH EV” as my “blog handle”, but I am back
>> (as TEG2) by popular demand.
I liked “The Original TEG”.
So… while we’re killing time waiting for the next blog, what’s everyone want in the White Star? I had this horrendous idea that the designers might do something stupid like put the trunk in the front because they can. I won’t buy a car that requires me to back into stalls at the grocery store. But then I saw the aforementioned interview with Elon Musk and he mentioned that the White Star will accommodate three child seats. Bingo! I don’t care about child seats, myself, but a woman I work with is expecting her third child and bemoaning the fact that she can’t find a vehicle that accommodates three child seats. Once again, Tesla proves that they really know what people want. I needn’t worry about trunk space.
I’ve read about adaptive cruise control recently – it slows the vehicle to keep a safe distance. I want that! I “drive by wire”, using the cruise control as low as thirty miles an hour, and am always looking for a better system. Something that’s always on, I can adjust by one MPH, and I can use even in traffic would be almost perfect. Give it the ability to accelerate quickly but in the most efficient manner when I [Resume], and a subtle indicator on the speedometer to show where I set it, and I’ll buy the car just for that.
At $55,000 it better have a driver memory system too. When I hit the keyless remote, the seats and mirrors should remember where I left them. Might be a little goofy when I grab my wife’s keys, but a driver #1 / #2 toggle button would remedy that.
Bluetooth is a “given” for a car designed by a Silicone Valley firm.
You’d think I’d want leather, but no. Great for couches at home; a pain in the butt for a car’s interior. Too hot in summer, too cold in winter, requires additional heating and cooling, and requires too much cleaning to keep nice. Make leather an option but discourage it with handsome two-tone fabric as standard.
Headrests for everyone!
As far a mileage goes, the more the better. But practically, I do 50 miles round-trip to work each day. On holidays or trips to Lake Geneva we’ll do 125 with four or five passengers. Add 20% fudge factor and that’s 150 miles. Throw in some optional photovoltaics in the back window deck and dashboard to trickle charge while we’re shopping, and I’m a happy camper.
Another article on Torque Vectoring:
www.autofieldguide.com/articles/060503.html
For the record I like TEG331/3 best
#Mark Tomlinson asks:
#…what’s everyone want in the White Star?
1) I have found the proximity sensors in my car’s bumpers to be surprisingly useful. I thought they’d be neat-but-not-necessary, but I’m relying on them more often than I expected. (I expect, too, that such an addition is last on TM’s list!)
2) A rear window automatic sunshade comes in handy at times.
3) Front license plate mounts. The Roadster photos I’ve seen never seem to include a front plate, but here in Los Angeles — or at least Beverly Hills — it’s required. Otherwise, you can end up with an unpleasant citation from your neighborhood meter maid.
4) Roof rack mounting channels would be nice.
5) Center mounted controls allow a passenger to utilize some functions — like door locking, which just might help prevent a domestic squabble or two. (”Honey, did you forget to lock the doors AGAIN? Well, dear, just press this button here…”)
6) Some small blank panel space with a cigarette lighter jack — or 110v jack — just behind. This will allow mounting and powering your favorite electronic device without running wires all over the car. It’s funny how my car’s navigation system, so advanced and chic in 2000, is now old and clunky. I might use a third-party device, but it just doesn’t fit cleanly anywhere.
7) Garage door opener or two.
8) For rear passengers — a bit of extra legroom is always appreciated, along with reading lamps and vanity mirrors.
9) If the car uses a “fuel” door, make it lockable so as to help minimize vandalism.
…and other such ideas. I have the sense that Martin and Elon, having driven a few luxury cars in their time, are quite cognizant of the features a $60-$70K car ought to have.
Mark Tomlinson,
Don’t get too carried away. For the sake of weight, I can’t imagine the Whitestar being as fancy as a Mercedes with the dozens of little features that do no good. Electric cars, unfortunately, are pricey. Unless Tesla Motors know of some sort of Voodo I’m not aware of or they invent some miracle, I don’t see the EV becoming mainstream for quite a while. In ten years though, I can see a world where every neighborhood has a plug-in car!
Take a bmw 3/5/6 series and look at all the acoutriments, nobody does a better job transcending excellent design. Tesla has much to chew on, to even be compelling to the average consumer of this class of vehicle. You are not just selling the best electric vehicle and all the great benefits of this. You are selling the whole package of the car experience from nuts and bolts under the body, to the feel of the interior surfaces, to the viseral sensations you experience when driving.
I also liked “The original TEG”
You could also try:
“The artist formerly known as TEG”
A team at MIT is working on wireless charging-for laptops, cell phones, etc.-said will work for range of 5 meters. So one day can drive Tesla in garage and it self-charges automatically.
# T.J. wrote on June 23rd, 2007 at 7:07 pm
## For the record I like TEG331/3 best
Hey man, that is the Final Insult!
# Mark Tomlinson wrote on June 22nd, 2007 at 10:24 pm
## So… while we’re killing time waiting for the next blog, what’s everyone want in the White Star?
* Electric powered (check!)
* Quick acceleration (check!)
* 4 wheel independent suspension with 4 wheel discs (given)
* Forged alloy wheels with creative design. (more than one style to pick…)
* Handles well (almost assured)
* Looks cool/stylish/hip (crossing my fingers)
* Small turning circle
* Not too wide (72″ max)
* _LARGE_ moonroof
* Good steering feel with just the right amount of road sensation.
* 50/50 weight distribution.
* Everything they could do to keep weight down.
* Rigid body/chassis.
* All expected comforts (AC, power windows, keyless entry, alarm, etc.)
* Kick a$$ stereo that can play MP3s from a USB memory stick.
* Best of breed VoiceNav/GPS system with maps of charging locations.
* Arm rests on doors and in the center console that are the same height and not too high.
* Self leveling xenon headlights.
* ABS (given)
* Airbags all around. (Elon mentioned “5 star crash safety”)
* Defeatable traction control.
* Electronic brake force distribution. (optimized portioning)
* Tunable regen force settings (dial controlled)
* Factory tinted windows (max that is legal)
* Push button keyless starter (like on the Prius)
* Dual climate control.
* Backup camera
* Under $40K (not a chance…)
Bonus points will be given if they pull off:
All-Wheel-Drive
4 Wheel Steering
Torque vectoring differentials
Night vision HUD
V2G
CHP Hall-Pass
(But I am not counting on any of these)
It will be tough to include all sorts of features and still keep the weight down and hit performance / range targets.
## I had this horrendous idea that the designers might do something stupid like
## put the trunk in the front because they can.
Hey - I don’t mind front trunks. My X 1/9 and Mr2 had them. Many Porsche’s do.
## White Star will accommodate three child seats.
I worry about it being too wide when someone says something like that.
I appreciate a car that can fit in a “compact” parking space.
## Once again, Tesla proves that they really know what people want. I needn’t worry about trunk space.
Or maybe they are trying to make up for the lack of trunk space in the Roadster?
## You’d think I’d want leather, but no. Great for couches at home;
## a pain in the butt for a car’s interior. Too hot in summer, too cold in winter.
YES! Someone who agrees with me. American’s are hung up on leather for luxury cars. Go to Australia, and many parts of Europe and you find high quality cloth even in higher end luxury cars. Leather is out of character with the “green” image Tesla is trying to promote. How much rain-forest did they clear-cut to farm those cowhides?
## Make leather an option but discourage it with handsome two-tone fabric as standard.
Sounds good to me. Or perhaps Alcantara (synthetic suede) if they just can’t handle a real cloth interior.
Still no progress (ground scraping) at the Tesla plant site in Albuquerque. It will located on the southwest side of the city a few hundred yards from I-40 - which provides excellent east/west access.
New F1 tech for road cars – the mechanical kinetic energy recovery system.
Its seems some people refuse to give up on the old ICE based power plants. Interesting idea though and I would like to see what it does for ICE well to wheel efficiencies. Let the war of words and ideas begin.
“The innovative combination of a Torotrak variator – providing mechanical efficiency that should be in excess of 90 per cent – with a flywheel of advanced construction, results in a highly efficient and compact energy storage system. Whilst Xtrac will supply variator units to its customers, the flywheels for these energy recovery systems are being developed separately by the Formula 1 teams themselves and their specialist suppliers. Torotrak will provide the control system expertise.
Torotrak and Xtrac believe that the variator-flywheel solution provides a significantly more compact, efficient, lighter and environmentally-friendly solution than the traditional alternative of electrical-battery systems.”
“The system supports the current trend in powertrain design for engine downsizing by providing a means of boosting acceleration, overall performance and economy independently of the vehicle’s engine and without the need for complex electrical-battery hybrid architectures.”
Full 3 page article available here gizmag.com/go/7396/
I have to say that I think, for the White Star and most future models, there has to be some type of on-board power generation. Sticking with the ‘electric only’ mentality would cause Tesla to fall into their own “perfect is the enemy of good” mistake.
The problem with ‘electric only’ is this; despite the fact that the majority of drivers commute less than 100 miles a day, virtually everyone has trips well beyond that limit. It may be once a month or once a year but it always happens. When those trips occur, people don’t want to have to plan their driving around the vehicles capabilities. Driving 200 miles and having to recharge for 3.5 hours would be a deal-breaker. On average I’ve had to make 1000+ mile trips about once per year and 500+ mile trips about 3-4 times a year. I would love to have a 100+ mpg vehicle but there is no way I would get one if required to stop every 200 miles for a 3.5 hour recharge.
The solution (in my opinion) is to reduce the amount of batteries to ‘only’ support about 100 miles of electric driving (still beating electric-only distance compared to any other mass-produced hybrid). That would remove about 500 pounds of batteries and should offset the additional weight of a high-efficiency generator or turbine. I lean towards the turbine because, properly designed, they a higher efficiency than your standard piston engine (but I’m not sure about the engineering issues). With this scenario, the standard daily drive is powered by the batteries and gets 100+ mpg and in the rare instances when traveling further, the on-board power kicks on and they (hopefully) get 60+ mpg. In this configuration they beat all other vehicles on the road for efficiency and still have excellent performance. They would also be vastly more marketable to the average consumer.
Separately:
Hey Tesla, any plans to enter the Automotive X-Prize with the White Star?
# Mark Tomlinson wrote on June 22nd, 2007 at 10:24 pm
##So… while we’re killing time waiting for the next blog, what’s everyone want in the White Star?
—
Well, my daily commute is under 30 miles round trip but my wife takes classes 65 miles away from home and we often visit family about 90+ miles away so a good 250 mile interstate range (75-80 mph) would be necessary. I echo your thoughts on leather, don’t want it! besides the reasons you stated it’s hard to be green when you are still using animal products. Lumbar support, electric adjustable seats and an adjustable steering wheel make it easier for us short folks to get comfortable. Sun roof, rear climate control and of course the all so important dual cup holder (or in our case water bottle holder). I would also prefer a spare tire(donut) over a can of fix-a-flat unless of course the tires are run-flat tires.
#Mark Tomlinson wrote on June 22nd, 2007 at 10:24 pm
## So… while we’re killing time waiting for the next blog,
## what’s everyone want in the White Star?
- Available in Europe
- Sporty (agile, not necessarily fast).
- Good handling
- Good looks
- Has a better range than Roadster (maybe with more advanced battery pack) Preferable over 450miles (I know, I’m dreaming).
- AC (being american this is almost guaranteed)
- Reliable GPS
- Quiet interior (almost guaranteed)
- Locking and anti-theft systems with electronic keys
- Standard size wheels so that I can put in studded winter tires in winter and summer tires in summer.
- Very good seats.
And everything you can add for what is left from 60000$.
# Mark Tebbutt wrote on June 25th, 2007 at 9:33 am
## New F1 tech for road cars – the mechanical kinetic energy recovery system.
## Full 3 page article available here gizmag.com/go/7396/
Hey - I like that! - on quick glance it looks very promising.
(thanks for the link)
Maybe we need a new movie: “Who Killed the Flywheel Car?”
www.time.com/time/magazine/article/0,9171,136542,00.html
findarticles.com/p/articles/mi_m5072/is_n16_v19/ai_19552593
www.bpa.gov/Energy/n/tech/energyweb/docs/Energy%20Storage/TRINITY.PDF
Jean wrote on June 25th, 2007 at 11:15 am
# Mark Tomlinson wrote on June 22nd, 2007 at 10:24 pm
##So… while we’re killing time waiting for the next blog, what’s everyone want in the White Star?
—
Almost forgot,
- All wheel Drive or the equivalent traction in snow
- Rear window defrost
- 120v/60hz power port to us the laptop or charge the phone on those long trips
- Keyless entry
- USB/Wireless connectivity so I/TM can monitor system performance (might be incorporated into the home charging system)
Is anyone else a little disappointed about the options on the roadster? This applies more to a true “different kind of car company” mantra than this particular model. I think it would have been nice to avoid the sales experience other car dealers are known for and not try and make crazy profits on add-ons that should be included.
I think VW has done a good job competing by including a lot in their base models so you don’t need to add it on. The manufacturer also gains since they have economies of scale on those “add-ons” driving the incremental costs down.
Something like a mobile charging system seems to be a requirement for an electric car not a $500 add-on. Also $15k cars have 8 speaker sound systems as standard you are asking $800. A high end XM satellite radio costs less than $200 (why are you charging $400 for this?).
I just seems to be something that is not inline with the philosophy of tesla motors. You have a chance to do things differently and I always dislike the idea of feeling ripped off. I remember on the last new car purchased it was 1999 and tape decks were still standard. The dealer wanted $500+ for a CD player at a time you could get a deck from a local retailer for $99. I hate that. If you need more profit / vehicle just increase the cost of the car don’t rip off your customers for the add-ons that should be included in the first place.
Perhaps come whitestar they will change their approach. It certainly would be nice to see.
For whitestar it would be nice to see an entry system like what toyota did with the prius. It really make a lot of sense and just works. If you have not heard of this before check out: www.toyota.com/vehicles/2005/prius/key_features/smart_entry.html and click on smart key.
You just keep the transponder on you and so long as it is in your pocket / purse you can open any door and start the car. Also with electric you never really turn it off (for example ESS fans / heater would always be active) so why have a start key? You can just use the car without any special action. I mean walk up to the car and open it (it unlocks / disarms like smart key prius) now get in the cart and remove the parking break and just start driving?
I think there is a lot about cars that when you take out the ICE can be rethought and really improve things. If you think of a car as a computer you can innovate a lot more quickly too for non safety related features. Being able to get upgrades online will happen in the future and would be great.
Let me comment on some other commenters!
## I had this horrendous idea that the designers might do something stupid like
## put the trunk in the front because they can.
I agree, DON’T even think about putting the trunk in the front. The car is electric, and that is already “too weird” to most people. The car needs to be as “normal” (although above normal luxury, handling, and performance are welcome!) as possible.
##Airbags all around. (Elon mentioned “5 star crash safety”)
Yes, airbags! 5-star safety rating is a MUST! I’m sure there’s millions of people yapping, “Electric cars aren’t safe.”
##We often visit family about 90+ miles away so a good 250 mile interstate range (75-80 mph) would be necessary
Well, for one, you can slow down to 65mph. (fueleconomy.gov/feg/driveHabits.shtml shows a graph with speed vs. mpg)
Two, 100 miles each way is 200, so with 50 left you’ve got plenty of room. Three, you could charge at your desination with the mobile charging station. Plus, the Whitestar will probably only go 250 miles (just my guess) if you pay for the premium version! The mobile charging thing is cheap in comparison at $500.
## There has to be some type of on-board power generation
It would certainly be nice if there was a tiny 1 or 3 cylinder or a turbine to keep your battery juiced up so that you wouldn’t need to rent a car for trips. Unfortunately I doubt this will happen. The 1 or 3 cylinder engine will require emmision controlls, belts, a spark plug, will have to pass the emmision standards, and the gas tank cannot leak in the event of a crash. Also, engines aren’t cheap. I’d expect at least a $5,000 price bump if it came with the range extender. I don’t know much, but I don’t think the “mini turbine” is a refined product good for use in range-extenders for EVs.
The only possible range extender I can think of for the Tesla Roadster is a genset trailer.
en.wikipedia.org/wiki/Genset_trailer
www.jstraubel.com/EVpusher/EVpusher2.htm
The only problem with a genset trailer is…well, safety. I don’t know if the government would classify the genset trailer as a car or what!
I’m guessing the gov’t would test the safety of the car with the genset trailer attatched too, and my guess is, with a genset trailer, it wouldn’t pass…I mean, this thing that weighs, what, 500 pounds cruising on behind you doesn’t sound too safe! What if you need to turn quickly or something. I personally would like to have a genset trailer for a Tesla. I mean, no weight is added tot he car and you can still go on long, long road trips. I’d love to go on a trip with a genset trailer! But safety standards may inhibit the genset trailer. Also may the complexity of engines. I’d expect another 9 months to be added just to create the genset trailer, if they were to make one.
Pete said,
“I think it would have been nice to avoid the sales experience other car dealers are known for and not try and make crazy profits on add-ons that should be included.”
“A high end XM satellite radio costs less than $200 (why are you charging $400 for this?).”
“Something like a mobile charging system seems to be a requirement for an electric car not a $500 add-on”
I agree with your first comment entirely. The dozens of add-ons are annoying. MINI is terrible. Their car basically comes standard with nothing but an engine and a transmission!
The XM radio selling for twice its price? It’s called business. The GPS system in cars cost three to four times as much as something like a Tom-Tom, so I wouldn’t be complaining.
A mobile charging system should be standard for most electric cars. But the Tesla Roadster isn’t most electric cars, it goes over 200 miles on a charge. I think a $500 mobile charging system is justible. (Have you seen the price of EV chargers? It’s pricey!)
I’d give Tesla Motors a break. Anyway, they can get away with this since it’s mostly rich folks buying this. Just don’t do it with your next models. Seriously.
Whitestar option:
I was particularly taken by the transparent roof being shown on the concept Infiniti EX vehicle. Seems to me that making this available (default to opaque) would allow a slightly lower roof (thus improving aerodynamics and increasing rance), eliminate the mechanics/weight of a moonroof (increasing range), and provide an almost convertable feeling without all the wind tunnel action.
# Mark Tomlinson wrote on June 22nd, 2007 at 10:24 pm
## So… while we’re killing time waiting for the next blog, what’s everyone want in the White Star?
No leather for me either. Raising cattle for food and clothing has massive negative effects on our environment.
- - -
Has anyone given thought to the sound of the horn? Are there any standards based on vehicle weight and type? Horns are not used often; but when they are you want a nice sounding one. I have a Volvo with a squeaky sounding horn that one would find on a smaller vehicle.
MichaelV, I agree with your “perfect is the enemy of good” opinion about pure electric for long trips. However, I see no reason to be lugging that ICE around all the time. Have you seen the smallest uHaul trailer they sell? It’ll hold about 3 golf club bags, or maybe a small ICE and fuel tank. Now, dragging a trailer around (even a light one) isn’t so good for your handling, but I don’t generally want to do the cones on I-85.
It really comes down to psychology. People buy SUVs “just in case” they need to drive off road, never mind that they never will. But lots of us really do go on long trips, and even though renting a car for those occasions is a totally reasonable thing to do, I know that I don’t want to have to do it. A small trailer with a high efficiency generator in it solves that problem. And if you make the generator produce AC, then it can double as an emergency backup generator for your home, which is just the sort of “what if” excuse that people love when they buy these things. “Honey, I know I just spent our retirement account on an electric car, but look! It came with a generator for use on long trips and in case the power goes out! And, did you know this car has a trailer hitch and 500 ft/lbs of torque?”
Also, putting the generator in a trailer means that when it dies (as ICEs do), I can just replace it, rather than get some expensive maintenance on my car. Lastly, it lets Tesla “stay pure” to the mission of providing pure electric vehicles.
Heck, Tesla doesn’t even need to make these (although it would be cool if they did, because then it could match stylewise). All I ask is that they design the power control module so that it can recharge the batteries from “the outlet” while driving. I’m sure that when electric cars comprise just 1% of the cars on the road, someone will make one.
P.S. The entire site is still broken in Firefox. I don’t know how many hits you guys get, but multiply that by .08, and that is how many people can’t see your site, and might be getting the wrong impression…
# Mark Tomlinson wrote on June 22nd, 2007 at 10:24 pm
## So… while we’re killing time waiting for the next blog,
## what’s everyone want in the White Star?
A few more:
* Auto up/down power windows for all 4 window controls (driver + passengers)
* Active suspension?
* Large easy to read controls for climate control, radio, etc.
(Too many BMWs have little tiny buttons with minuscule labels)
Dials or sliders are preferable to up/down buttons.
Hey jonas meyer,
What version of FireFox are you using? Just tested and did not show any problems (2.0) visiting the blog, gallery, purchase page etc.
re: reducing the size of battery pack to make room for generator
You’d have a series hybrid then, not an electric car. And this would put a much higher strain on your battery ( individual cells ) in average use, meaning less life out of it. Consider this: you have 25 mile commute, and a 50 mile pack. This will mean you cycle the battery to 50% SOC each day. Vs. 25 mile commute and 200 mile range, where you only exercise the battery to 87,5% SOC.
Also, lets say your consumes about 30KW of power at 60mph cruise. Having a hypothetical 1000-cell 50-mile battery pack means you draw 30 watts from each cell. Now substitute that for a 200 mile pack, means you draw four times less from each cell, i.e. roughly 9 watts.
Given identical cells in both packs, with larger battery the individual cells get cycled much less and peak power drawn from them is much less in average use. Which means much better battery life and depending on cell peak characteristics, better available power.
Given the added complexity of series hybrid ( complexities of both worlds, battery electric AND ICE power ) i think lugging around larger battery pack is lesser of two evils, vs. lugging around dead weight of ICE.
I think for long drives, series hybrids with direct methanol fuel cells or something like that will win in the long run. In the near term, just rent a diesel guzzler if you can.
jonas meyer,
Just a thought: What about placing/packing a small generator in one of those arodynamic travel case thingy’s that attach to the roof of cars. Probably be much more efficient than dragging around a trailer. Refiling the generator with gasoline while it is on top of the roof might be a pain. Not very accident safe either.
#Joseph wrote on June 25th, 2007 at 5:52 pm
##Let me comment on some other commenters!
###We often visit family about 90+ miles away so a good 250 mile interstate range (75-80 mph) would be necessary
##Well, for one, you can slow down to 65mph. (fueleconomy.gov/feg/driveHabits.shtml shows a graph with speed vs. mpg)
##Two, 100 miles each way is 200, so with 50 left you’ve got plenty of room. Three, you could charge at your desination with the mobile charging station. Plus, the Whitestar will probably only go 250 miles (just my guess) if you pay for the premium version! The mobile charging thing is cheap in comparison at $500.
I’m sure my driving habits are about the same as the rest of the nation. I generally like to keep to the speed limit it just seems less intimidating to go with the flow than to have a tailgater upset because you are traveling 10 mph under the posted limit. BTW those tips were geared toward ICE vehicles, I’m sure there is an EV equivalent but I didn’t see it on the site. When I visit family we don’t necessarily stay at the house or apartment all day and it would be nice to use the EV instead of an ICE while scooting around town. if I had the time I would utilize the portable charger at the house but getting an extension cord that long for the apartment dweller would be a challenge. The Whitestar should be able to accommodate those short roadtrips or it will be considered a commuter vehicle only.
What Im hoping for most in the WhiteStar is rapid recharge. I believe that rapid recharge would help cement future batt EV success by creating a market for charging stations. Although the range would be reduced, the benefits of being able to take a roadtrip with the car would make up for it. Come 2010 and you can buy a desirable batt EV that is supported by a growing network of charging stations, people will start to question the ‘hydrogen economy’.
As for performance, 0-60 in under 5 seconds would be really great. At the very least, the number to beat is 5.4 seconds (the fastest 5 series 0-60 time).
kert wrote on June 26th, 2007 at 12:46 pm
# I think for long drives, series hybrids with direct methanol
# fuel cells or something like that will win in the long run.
And even longer run battery wins again. It only needs recharging station network. Many new innovations give 5-10 minute recharging for batteries, so recharging for less than that (you don’t drive your 400mile range BEV empty, right?) equals pretty much same as filling gasoline (or ethanol) tank.
Once you start to have decent number of BEVs into road those stations start to appear as service naturally even if nobody is promoting them. First as extra service for roadside restaurants or something like that and later as genuine recharging stations. If you can make money out of it *someone* will do it.
All you need to establish something like that is roadside restaurant/service station, decent grid connection and ESS of your own. Because ESS in service station is not mobile it doesn’t matter if it is big and heavy, so it can be made much much cheaper than car ESS. Flywheels or lead-acid batteries I guess for short run, more exotic later.
Some calculation for (big) recharge station with wild guestimates:
Lets assume you get 10 cars a hour on average recharging for 60kWh each. That’s 600kWh. So 600kW connection is what you need from grid. That is a one big connection to grid. 1kV 600A. For three-phase that is roughly 350Amps/wire. But very much doable if station creates enough revenue to pay connection costs to power company.
Then lets say you get 35 cars / hour for four hours peak time. That is 25 more than grid can provide. So you need to collect 4*25*60kWh energy in EES = 6MWh. Quite a lot. 100 Tesla battery packs
. But if price is less… lets estimate 1/10 of Tesla battery. That is then 2000 / battery. 100*2000 = 200000$. Still very much doable, cause that is one-time cost.
I’m not financial expert but I think salaries cost a lot more than anything else there. 10 guys working for 2000$ / month would be 20000/month + electricity from grid + equipment maintaining. Lets say 40000/month for expenses.
You got 240 cars / day. That is roughly 7200 cars / month. So you would need to get 40000/7200 =~ 5.55$ / car for this to be profitable. (can’t be that small. I was expecting something like 20$ / car).
Money makes the world go around
The world go around
The world go around…
:-)
what’s everyone want in the White Star?…
My daily commute is handled by any range, However my wife and I live 220+ miles from both our parents and 230 miles from a camp we visit/volunteer twice a month for the summer months.
I stay at each place for a few hours/days where I could charge before I go back home, So…. I really would like/need a safe, 250+ mile range, fun to drive car for my WhiteStar dream.
A HA! It’s a cookies thing. In firefox (latest 2.0 version), if you wont let the site set a cookie for you, then it infinitely reloads. Ok, so it’s not as big a bug as I thought, but it is still pretty big.
We are in the middle of a lull in new blogs. I am hoping this is because everyone at Tesla Motors is really really busy, (this would be a good thing). Meanwhile back to features we would eventually like to see on any Tesla Motors vehicle. Never mind I just want hear about “THE FIRST DELIVERY”. Like the good old boy says “LETS GET ER DONE”
Tuesday again, and still no new blog. Am I jumping the gun, or are you folk just really busy? Maybe I got spoiled but I like to think the blog is one of the key elements that set you apart from GM and the rest. Oh, and that whole electric car thing.
All these comments on the White Star got me thinking of other things I’d like to see. Where I coming from is that an EV will last much, much longer than an ICEV. In 2010 or so I’ll be in my mid 50’s and looking for a luxury car that will take me into retirement and beyond.
A lot of manufacturers are boasting that the car stereo will accept your MP3 player. Big frickin’ deal. They add a 49 cent phono plug I can pick up at Radio Shack and the marketing department has a hay day. I want a USB plug. There are plenty of aftermarket radios that have them.
Not so sure about the panoramic roof some people have mentioned. Popular Science dreamed up an energy efficient car and discovered that enormous savings can be achieved by better insulation to reduce the heating and cooling demands. My car was a toaster oven when I came out of work this evening. I don’t need more glass. (It would be cool to look at, though). And glass is heavy, although I suspect Tesla would use a lighter weight plastic. Besides, I drive into the sun both going to and coming from work and glare is already a problem.
I liked the idea of letting the aftermarket suppliers come up with a plug compatible range extender. But Martin once mentioned that he and Elon differed on the idea of adding photovoltaic cells to the car body. I’m all for it. Whilst going on a day trip to the Galena territory, I won’t be running an extension cord across the sidewalks. I only visit some members of my extended family for weddings and funerals; God forbid that I should want to plug in at the funeral home! Earlier I mentioned the idea of adding cells to the dash and the back window deck for a variety of reasons. They wouldn’t add unsightly “trim” to the exterior. They would be better protected from the elements. There’s plenty of unused space there in most vehicles. And I suspect 30% efficient cells will lower the interior temperature in summer by absorbing a portion of the energy. (Probably all wrong about that). Goofy as it sounds, I’d love a big photovoltaic array that fits in the trunk and can be popped out and aimed at the sun when I’m parked in the far end of the mall parking lot.
I want plastic side panels! Don’t get me started on how stupid GM was for dropping them. Bottom line is that I want the car body to last as long as the power train.
When can we expect the next blog entry?
The Tesla does NOT and should not, try to accomodate the needs of long-range driving at this point. Certainly most people will not want to drive 1000+ mile trips having to stop every 200 miles for a 3.5 hour charge. But that should not be a consideration for the car at this point. There is a HUGE niche for this car to fit into the lives of people who
a) do not have these long-drive needs
b) have more than 1 vehicle available
c) willing to rent or find alternate transportation for long trips
We need to get rid of the notion that Generation #1 of the 21st-century EV has to be able to do EVERYTHING that an ICE car can do. Just like complaints about the first-generation iPod: only 5GB drive, only 5-6 hours battery, monochrome, no picture or video. Guess what, people bought them like hotcakes and the success and technical advance made possible the current models.
For EV to fill the gap for cross-country driving it just needs about another doubling of range. Most people can easily live with 500 mile per day travel. Stop for the night and recharge. The day will come and increasing success of EVs (bought by people who can live with TODAY’S limitations) will lead to the advances and gradual adoption of infrastructure (charging stations). In fact I would expect the proliferation of charging locations to be much quicker than happened with gasoline service stations. Who needs a service station when you can plug-in at your motel, etc?
Okay I consider myself a very patient man, but where is the new blog? It’s been two weeks!!!
# Mark Tomlinson wrote on June 22nd, 2007 at 10:24 pm
## So… while we’re killing time waiting for the next blog,
## what’s everyone want in the White Star?
Along with all the features that everyone has described, there are some things that sway me to buy one car over another.
Those things include:
* Fit and Finish
* Ergonomics
* Materials Quality
Fit and finish shows up in the size of gaps between the doors and body, trunk lid, etc.
Ergonomics has me finding that all controls seem within reach and in logical places. A car that feels “natural” to drive is preferable to one where you have to learn.
Material Quality is important for the long term. I am less inclined to buy more Ford products because (compared to Toyota) I have found that the dashboards tend to crack or the glue attaching the instrument cluster to the dash material tends to let go over the years and you get gaps, seams and rattles inside the car.
Cars can sell with lower quality materials, but you really need good quality glues, foams, rubber and plastics for everything to hold up in the long term.
Couple more “Whitestar” suggestions: the new Corvette electric push-button inside door latch is quite nice. And now for something completely different, as an option: an oversize, fat center armrest between the front seats (top opens, as usual,for storage below)-only this optional armrest also lowers down to be flush with the front seats (seeing as how ain’t no transmission tunnel in the way) , so you can sit on it (upholstered like seats, extra padded top ) -making for a bench seat option. This way the Whitestar ” has the potential to seat six- or have an extra spacious feel for two front seat passengers.Retro nice, huh?-sure, sure: swell ! -Bogie would dig it .
give me something to work with tesla, no new blog entry and i might die of anticipation
# T.J. wrote on June 27th, 2007 at 10:04 pm
## “Whitestar” suggestion: an oversize, fat center armrest between the front seats
Yeah - when I badgered Toyota / Lexus to put an armrest into the IS300 the Toyota engineers responded back something like “Silly American’s and your armrests. We just got through with the cupholder craze!”
I guess some people could care less about armrests, but those that use them really like them.
alternet.org/environment/54218/?page=1
Great article entitled “The Great Biofuel Hoax”. This issue needs more publicity to get us away from this ridiculous notion that we can grow enough fuel to replace oil. It’s been known for a while that it won’t work, and we can either cut our losses now, or experience years of problems and then watch the market implode.
If you haven’t noticed, the Media page has a new entry to a CNNMoney article: Business 2.0 - The 50 Who Matter Now with a link to Martin Eberhard in the ranking at #19. money.cnn.com/galleries/2007/biz2/0706/gallery.50whomatter.biz2/32.html
However, if you didn’t look through the other 49 in the list you might have missed Elon Musk, ranked at #43. money.cnn.com/galleries/2007/biz2/0706/gallery.50whomatter.biz2/8.html
Two ideas for Whitestar sedan that got lost in bloggerspace (?): central vacuum system for the car (with outlets in front, back & trunk), plus liquid crystal “flip a switch & make windshield opaque gray to block sun in parking lot”.
I have no problems with leather. It has great feel and the smell is wonderful. It lends an organic feel to a car. Using a leather product is not promoting the raising of cattle. People eat beef. Should we just throw the skins away?. In any case, it’s easy enough to offer the customer an option.
#The Tesla does NOT and should not, try to accomodate the needs of long-range driving at this point. Certainly most people will not ##want to drive 1000+ mile trips having to stop every 200 miles for a 3.5 hour charge. But that should not be a consideration for the car ##at this point. There is a HUGE niche for this car to fit into the lives of people who
##a) do not have these long-drive needs
##b) have more than 1 vehicle available
##c) willing to rent or find alternate transportation for long trips
The problem your point ‘a’ is that the huge niche you’re referring to still require long distance driving every once in a while. I know very few people who never drive over 300 miles at least once a year. The problem with ‘b’ is that if I spend $50k for a super efficient car, I don’t want to be stuck driving my 15 mpg SUV/truck on a long distance trip. As for ‘c’, it’s feasible but, again, I don’t want to spend a lot of money for a primary car and not be able to use it.
I *think* I’m like most people. I have a primary car, then other vehicles that are more like toys than transportation. I have my everyday car, a 2-seat sports car and a motorcycle. I would love to get a White Star to replace my everyday car but not if it meant that I had to take the two-seater or the motorcycle on all long distance trips. Yes I’m sure they would sell plenty of White Start even as electric only, my point is that the demand would multiply greatly if they provided some means of realistic long distance driving (ie, no 3.5 hour recharge).
One of the problems I see with today’s hybrids is that you can’t get very far on electric alone. Making a car that could deal with 95% of daily driving needs on electric and only use gas on those rare long drives (or when you forgot to plug in last night) would be ideal. Even the Chevy Volt is planned to only go 40 miles on electric alone and that’s with assumed 2009 technology (and the designs so far are pretty ugly IMO).
Quick charging would be a great solution for the distance problem but so far the technology is limited and prohibitively expensive. Also you run into the issue of supplying an amount of power that isn’t currently available. An optional generator device that you could remove when not in use would be great but not especially realistic (that I know of). The most realistic solution that I could think of was the small on-board generator.
Other items I’d like to see:
- UV tinting on the windows to lower internal car temps and extend the interior’s life
- All-wheel steering (if that would give better track performance)
- Fold down rear seat for additional cargo space
- Traction control on/off switch
Unrealistic options:
- Directional EMP for those…individuals… with loud subwoofers
- An electronics suite to scramble speed detector return signals
++ on the fold down back seats. In fact, that is kind of a must. It makes any sedan like 200% more practical.
++ on the UV window tinting, and the LCD window blocking. Not sure if LCD likes being in direct sunlight for years, so I don’t know if this is practical at all, but it has the added benefit that it will polarize the light coming in, eliminating much glare (if they install it so it blocks horizontal polarized light). Actually, just polarized windows might go a long way towards cutting interior temperatures in the hot sun.
++ on the armrest / bench seat. That is a really innovative feature. As Cake says, “Stick shifts, and safety belts, bucket seats have all got to go…”
On the other hand, I really don’t see why you can’t stick a generator in a trailer. My friend has a 2KW generator for backup for her house, and it is small enough. You probably have to do crash testing on it, but they certify ICEs for crashes all the time. All you need is a white star that can charge and drive at the same time (dunno if that is easy, but it SOUNDS not to difficult). Then you have transportation that can do the first 3-4 hours pure electric, and the rest of the day of driving guzzling gas. As you said, people buying a $65K car have an expectation that it will serve ALL their needs (even occasional moving and or road trip needs). And unlike the Roadster, the White Star is NOT a toy for the rich. It’s practical transportation for the mostly rich, so it actually has to be engineered to a higher standard. A simple $4K trailer solves that. And, as charging tech changes (say fuel cells become feasible), you just swap out the trailer.
- Directional EMP for those…individuals… with loud subwoofers
Aww man. Second best option for a car ever, right after James Bond’s completely impossible (with 2005 tech) invisible car, and right before the rocket launcher and ejection seat.
# jonas meyer wrote on June 29th, 2007 at 7:34 am
## it has the added benefit that it will polarize the light coming in,
I have heard that polarized glass on a car is a “no-no” because it could cause a problem if the driver wears polarized sunglasses.
You could get in a situation where you tilt your head and suddenly you can’t see out the window anymore.
We would love to see a new blog post - it’s been two and a half weeks. Even just some pretty pictures of the new VPs would be fantastic! How is the VP crash-testing going? I heard Elon and Martin were going to drive around the first production cars for a month before the rest would begin to be delivered, which sounds good. Could you post more of those beautiful NYC shots? Is there a single page where we can find all the blog pictures of the Roadster? I remember one with the ocean in the background that was really nice, but forget which blog post it was.
Is there a timeline for the webstore? The first Tesla Motors Store opening? Albuquerque groundbreaking, LEED plans?
Thanks again for all your hard work - for the sake of the country, I hope you make it!
—
Editor’s response: We just published a new blog on regen braking.
Assuming by 2009 WhiteStar averages 250 miles/charge. Are those 250 miles based on one passenger? Would one still average 250 miles if the vehicle has 4 or 5 occupants?
how about a free iphone when someone buys a new car from you???
At last!!!
I live in Perth Western Australia and was a member of the electric vehicle association Perth branch (now defunct through lack of progress ib the industry). It has taken the development if the mobile phone to provide a battery with sufficient power to weight ratio for the electric vehicle to come of age.
Could you please tell me the cost of replacing the battery pack as in Australia we do not dispose of our cars after 100,000 miles, many are still going after 1,000,000 miles.
Is it possible to use a titanium alloy to improve the weight/strength of the wheels after all the ring pull on aluminium cans to improve there strength.
While you use regenerative braking I would expect you have disk brakes for emergancy stoping, is this the case?
Is the car using LED lighting for all but the head lights reducing further the power requirements and extending the life of such components. (LED brake lights turn on quicker and so reduce tha chance of a rear end collision)
While I am now semi-retired and such a vehicle is out of my price range (but on my dream list for the loto win).
I would like to see such a car mass produced for the world market (right hand drive option included) as the manufactures of hybrid cars are having problems meeting demand.
The problems in maintaining the modern petrol driven(Gas) cars are far greater than those of maintaining an electric car.
The time is now.
Please consider.
Best wishes for your success.
John.
# John Cornwall wrote on July 4th, 2007 at 8:36 pm
## While you use regenerative braking I would expect you have disk brakes for emergancy stoping, is this the case?
Apparently the regen comes into play when you let off on the “accelerator” pedal.
Yes, there are traditional “friction brakes” that can stop you as quickly as you need.
## Is the car using LED lighting for all but the head lights reducing further the power requirements and extending
## the life of such components. (LED brake lights turn on quicker and so reduce tha chance of a rear end collision)
Yes, you should explore their site more. LED brake & signal lights are included.
I discovered this hi-performance electric car make some time ago and I consider that the contribution Tesla is making to the electric car industry is huge, since it shows how electric cars are superior in both efficiency and performance. However, a lot of work is still to be done until people really want to by an electric car. Here is where I would like to explain what seems to me an interesting way of promoting Tesla car:
Since Tesla is a sports car company, what about developing an electric-drag car?
As far as I know, a car using a high power density motor (or even one motor in each wheel hub) and some high power density storage device (such as ultracapacitors), would be extremely light and powerful. It seems it would easily be competive as compared to ICE cars.
I know similar initiatives have already been carried out. However I consider current technology would outperform those previous experiments.
I think Tesla has the required capabilities to develop this idea and it can be a great investment in terms of marketing, since new segments (less concerned wiht the environmental issues than with car perfomance) would become potencial customers.
I do not know if this is the right place to drop this idea; I just wanted to let Tesla peolple know about this.
Thank you
# John Cornwall wrote on July 4th, 2007 at 8:36 pm
# Could you please tell me the cost of replacing the battery pack
# as in Australia we do not dispose of our cars after 100,000 miles,
# many are still going after 1,000,000 miles
What kind of car engine is still useful after million miles? I bet repair costs for it are already reaching new car price. I have seen few useful old upper-class cars with 400000km in their meters, but that is only about 1/4 of million miles. It takes forever to even drive that long distance (8h a day, 100km/h average would take approx five and a half years to drive million miles)
Anyway. Battery tech is advancing fast. I bet there is no estimates because it is impossible to predict what kind of battery you would get in your car in few years from now. I bet it would be cheaper *and* better than current tech, but how much cheaper or better is anybodys quess. Tesla Roadster battery pack costs about 20000$. I bet replacement battery pack will be cheaper.
I was just looking at LED lights and they appear to have 50,000 to 60,000 hour life spans, so I’m guessing that most people may never replace the lights in their Tesla.
Everything I am reading about them is that they are cool running, very efficient and long lasting but they produce a lot less light.
I am curious about the light output that the Tesla is getting from them compared to their competitors who will have anything from Halogen to Xeon light fixtures. Most of these systems put out about 1,000 lumens with low beams on. With HIgh beams some of these systems are running 2-3,000 lumens or more.
Is driving the Tesla at night on a winding back road at night is going to be as safe?
Maybe they could even blog about how LED lights work in the Tesla. I’ve seen after market kits that mention traditional blinkers don’t work on LED’s because of the low power draw, so I’m betting that they did a lot of interesting stuff to optimize the power utilization while making all the systems work.
Nevermind, I see that they are still using halogens for the driving lights, which makes sense since the only mention i could find about LEDS for headlights said that they would burn out quickly if put together in a headlight assembly.
# Francisco Cebrian wrote on July 7th, 2007 at 11:08 am
## Since Tesla is a sports car company, what about developing an electric-drag car?
Electric drag vehicles are already here, for instance see these:
www.currenteliminator.net/
www.killacycle.com/
# mark wrote on July 8th, 2007 at 4:55 am
## Nevermind, I see that they are still using halogens for the driving lights,
I think you meant “headlights” not driving lights. Yes, LEDs have become bright enough to be used for brake lights, turn signals, and even traffic lights. I notice the police now use LED lights on their new low-profile light bars as well.
www.policeone.com/police-products/vehicle-equipment/light-bars/articles/118422/
I think it is just a matter of time before we start seeing LED headlights as well. Just as the eMotor should replace the ICE, I think LEDs will replace filament bulbs in all applications in a few years. They are just so much more efficient and last so much longer.
Big screen TVs and laptops are starting to use LEDs as well.
laptoping.com/notebooks-led-backlight.html
Hybrid Technologies announces their Mini Cooper based EV is going into production now:
www.hybridtechnologies.com/media.php
www.hybridtechnologies.com/media/pdf/mini.pdf
Any ideas on price on that MINI. The basic car is already quite expensive for what it is. Tesla’s plan still looks good to me. Start off with a premium car and work your way down to a mass-market model. Just don’t take too long getting there!
# andrew kelsey wrote on July 10th, 2007 at 4:57 am
## Any ideas on price on that MINI.
www.autobloggreen.com/2007/04/23/hybrid-technologies-working-on-mini-cooper-ev/
“Would you pay almost 60 grand for a Mini Cooper?”
The Lexus LS460 has LED headlamps
www.lexus.ca/lexus/experience/en/home/vehicles/tourandhighlights/DU46FC2008/veh_dt_exterior.jsp?model=DU46FC&year=2008
This is a follow-up on an earlier comment made by, I believe, Darryl Siry, concerning there being a video game in development that will have the Tesla Roadster in it.
It looks like the “mystery” video game is the upcoming Project Gotham 4 for XBox 360.
www.roadandtrack.com/article.asp?section_id=34&article_id=5558
2nd paragraph of the article:
Developed exclusively for the Xbox 360 platform, PGR4 blends simulator-like racing action with an arcade feel. Players can choose different modes of play such as single-player, local multi-player or multi-player over Microsoft’s online connection called Xbox Live. The 100 cars and 30 motorcycles, as is typical of these games, represent the crème-de-la-crème of motorsports. Your typical arsenal of superbikes and supercars is present, of course, but a few notable additions stand out. Take, for example, a 1955 Jaguar D Type, all the way out to a Tesla Roadster. For those who like motorcycles, how about a 1960 Honda RC161?
Thanks TEG2. No I wouldn’t want to pay 60 Grand for a Mini…even an electric one! Tesla are still out on their own in producing a thoroughly tested and crashed car for a sensible price that has great performance and acceptable range. They use batteries that aren’t made of unobtainium and should stay the course. I am beginning to think that maybe they should consider in-wheel motors in future though. Previously I ruled these out on grounds of unsprung weight but it seems that isn’t as much of a problem as I thought. A larger car like the Whitestar might benefit from the PML Flightlink in-wheel motors used in the $300,000 Lightning combined with Tesla’s ESS. With the 640bhp quoted, performance shouldn’t be any problem! I know in-wheel motors are a problem in the States as removing the conventional brakes would make the car illegal but maybe legislators could be convinced if sufficient testing were done. No transmission would be required either, producing further weight and cost savings. Just a thought.
Just an afterthought on those in-wheel motors. Surely PML or maybe Tesla should be trying to produce motors with half the weight and half the power. Nobody actually needs 640bhp in a car but you can’t use just two motors on the rear wheels as then you wouldn’t have any braking for the other two wheels. Four lighter motors with say 80bhp each would still produce a car with an excess of power and presumably use up much less battery power.
Google offers employee ride-share in plug-in hybrids:
blogs.business2.com/greenwombat/2007/06/google_powers_p.html
(although Toyota seems to be on a mission to disassociate itself from 3rd party battery modifications for the Prius)
Andrew Kelsey: Tesla could just as easily get 600+ horsepower by using a bigger motor like the one they have now. I’ll get to why they don’t in a moment…
Hub motors have other issues besides unsprung weight and legislation. For one, their reliability is uncertain–running high-voltage lines to two or four wheels seems a bit hazardous, plus they don’t have a lot of road history (thousands of miles versus millions for inboard AC induction motors). Another, and this is a big one, is that there aren’t a lot of sources for hub motors. If Tesla commits to using PML Flightlink, they’re locked into a single vendor, creating all kinds of risks. As Tesla Motors currently makes their own motors, they have a lot of confidence in their supplier
Now, back to the 600 HP thing, in order to get that much horsepower, you have to suck a lot of watts out of your battery pack. The Tesla ESS is based on standard cheap lithium ion cells and it really strains just to put out enough juice for the Roadster’s current 250HP motor if you really drive it hard. A different battery system would be necessary to get 600+ HP, and there aren’t (currently) any good choices. You’ll notice that Lightning chose AltairNano, and the result is the $300k price tag. A123 or Lead Acid could also deliver enough power, but sacrificing a lot of driving range.
The Tesla Roadster is presently very well balanced. The battery system is relatively cheap, yet still has enough power output for 0-60 in 4 seconds, the motor is exactly big enough to handle that power, the tires are all sized carefully, unsprung weight is quite low, overall weight is still excellent for its class, and the price tag is reasonable for its performance characteristics. If you change anything, there are ripple effects to many other areas.
The only thing Tesla really needs to do right now is get the car into customer hands, so they can say, from personal experience, that the car is perfect and nothing should be changed
Someone may want to update Arnold on the latest #s…
Recently added video:
www.youtube.com/watch?v=N-YgE_H0FaI
Arnold Sez:
“Tesla Motors Roadster…
0-60 in 4 seconds (OK)
135 MPH (OK)
250 miles without charge (um, well … )
Cost: $100,000 (OK)
2nd version will cost $50,000 (??)
3rd version will cost $38,000 (???)
“
Regarding Project Gotham 4. . . It would be nice if the Roadster eventually appears in a game that doesn’t require me to buy something from Microsoft, because that’s one thing I’m not going to do. I have some principles, you know.
# Tony Belding wrote on July 18th, 2007 at 7:49 am
## Regarding Project Gotham 4. . .
Yeah - I already bought the PS3, so I am hoping the Roadster shows up in “Grand Turismo HD” someday…
Thanks Ryan. I agree, obviously, that Tesla shouldn’t change a thing on this car and I only wish I could afford one. All I’m saying is that I don’t think we should rule in-wheel motors out altogether for the future. As I pointed out before I don’t think 600bhp is desirable but smaller, lighter, less powerful units on all four wheels could be worth considering. I’ll shut up about it anyway as I guess it is a bit off-topic.