Tesla at Jan 15th AX - Drive it!

[Mmagus]

Never did hear the "raffle" results for who got the Tesla ride on the track

I believe the raffle was in Tesla's hands. I did see PCA members bring them through start (I was there most of the day) so there were winners. it was uncanny to have them blast off with no wheelspin, just a very light hum ann th soud of tires rolling. I saw them sneak up on a few corner workers throught the day!

[ttweed]

Never did hear the "raffle" results for who got the Tesla ride on the track

Of course, I checked around lunch time to see if I had won a track session, but no joy. The only name i recognized from the cards that were drawn from the jar was Craig Hill, who usually drives a blue GT3 with his lovely wife, Michele. He was walking up to the Tesla booth with his helmet right after my parking lot test drive, and I had to stifle my jealousy.

Hopefully, some of the lucky winners are members of the forum and can report on the car's handling at the limit. I must say from my brief experience that I was startled by how much performance the Tesla engineers have wrung out of the electric drivetrain. They truly were focused on performance, and making the roadster a sports-purpose car. Most EVs are designed for efficiency and utility rather than performance, and acceleration is limited to more "normal" levels of a street car. This is a compromise to preserve the battery pack and not squander the available power, but rather to maximize range, which is a concern for people who must commute fairly long distances on a daily basis. I can say without a doubt that this compromise was not implemented in the Tesla. They chose to utilize all the power available from the AC motor and make up for the battery drain under such circumstances with a huge battery storage capacity. The 56kWh pack in the Tesla is over twice the capacity of the 26kWh pack in the Nissan Leaf (whose electric motor is way less than half as powerful), yet the car weighs a full 600 lbs. less. Of course, it can only handle 2 occupants and little cargo as opposed to the 5 passengers plus trunk area of the econobox hatchback, but driven judiciously, it will go over twice as far without re-charging, accelerate over twice as fast, and achieve a top speed 30 mph higher than the Leaf. This is pretty amazing engineering.

After seeing how wide-open they allow the motor to operate, I definitely have to lower my estimate of what the range might be when driven "flat out" on the track, though. They are allowing the 288hp induction motor to draw prodigious amounts of juice from the battery to enable the kind of wide-open performance it achieves. I can see now how 55 laps in a track environment could use 80% of the available charge under those conditions. The Top Gear track at Dunsford Aerodrome is about a 1.75 mile circuit, so 55 laps would be 96.25 miles. If what the Tesla spokesperson said was true, that the car never had less than a 20% charge and did not need to be pushed off the track with a dead battery, as Clarkson dramatized it, then the Roadster's efficiency dropped by 50% when driven flat out, which is quite a bit higher than my previous 30% estimate, reducing available range from the claimed 245 miles to something like 120 or so. This makes sense to me now, though, seeing how little "governing" of the drivetrain is done to limit its power consumption. You would have to drive the car in a "hypermiling" manner to achieve maximum range, and that would not include stomping on the go-pedal exiting every corner!

If you took this technology and applied it to a purpose-built autocross car, the results might be quite startling. Stripping the car of creature comforts and also reducing its weight by installing a smaller battery pack capable of only completing the 20 miles or so necessary for an autox, along with some sticky rubber, i wonder what could be achieved? While there still may be a weight disadvantage to ICE cars, the fact they are not "gearing dependent" in order to keep the motor in the peak torque range may make a big difference--no shifting anywhere around the course, and no waiting for the engine to "ramp-up" out of those slow second-gear corners! I didn't really see what kind of times were being turned by the Teslas, but of course this is very driver and tire dependent. I did see that they were running the Advan Neovas, which are a very capable S/S tire. Did anyone notice how their times compared to the S/S Porsches?

I do know that there is talk in the SCCA of developing EV classes for Solo racing. Endurance racing is a whole 'nother ball of wax, but I know that in Europe, they are launching an EV road racing sprint series next year: http://www.evcup.com/ I guess we'll see how that goes. I wonder what it will be like to see cars ripping around a track without the usual engine noise? Less satisfying for fans, possibly, without the aural input?

And don't forget the EV racing motorbikes: http://ridemission.com/motorsport/mission-r, and the Lawless Rocket Drag Bike that was built by Orange County Choppers and
did 177 mph @ 7.46 in the 1/4 mile! http://www.nedra.com/, not to mention this San Diego-based drag car company that I encountered at the auto show last year: http://ssi-racing.com/. "Lucky Dave" M. was talking to me yesterday about his days as a sponsored electric RC car racer! The near-future of this technology is going to be very intriguing, to say the least. Our dino-powered cars are not going to be displaced, but there are going to be some fun alternatives in motorsports developing.

TT

[Jad]

While I didn't drive the Tesla, I did instruct in one for 3 laps. To me, some things about the car were VERY impressive, unfortunately, some were pretty pre-production.

The Good: The acceleration was amazing, the handling seemed quite good, the ride was smooth and comfortable. As Tom said, the potential performance was amazing. No oil changes, much less to break, all huge pluses.

The Bad: The traction control was completely invasive. At any sign of wheelspin, it shut off the motor. It didn't seem to retard, or reduce wheelspin, it stopped it and waited. Can't tell how much was car vs driver, but I have never seen such aggressive t/c. The first corner with it off, immediately resulted in a spin as the torque kicked in. Clarkson may have been exaggerating things, but not by much. My student was borrowing the car, so he had taken co-workers for joy rides the night before, figuring he would plug it in overnight and be good to go. He didn't have a 240 chargers, so he estimated in 6 hours, he got 1/8 charge . Needing a minimum of 40 miles to get home without destroying the batteries by running them dry, and starting at 52 miles range, he was only able to do 3 laps comfortably as each lap took about 2 miles off running in normal mode, not performance. He said you get about 5 miles range per hour in a standard plug

A few nitpicks, you couldn't read the battery gauge in the sun as the cheap lcd washed out completely which leads to the other nitpick, the interior was nice for a $20k car, but ridiculous for ~$140k.

Overall, I felt this was a pre-production car, with amazing promise for the Model S due out soon. I will certainly consider the S if it is anywhere near the car they have promised as it seems to be a complete car, not a drivetrain in a test vehicle that wasn't completely developed. To be fair, that is what the Tesla is, they were years ahead of the competition in developing an electric car and had to emphasize the battery portion, not details like traction control, interior materials or track performance (LSD?). They are very much state of the art, green transportation, and as such, it far exceeded my expectations in the limited experience. Thank you Tesla

Let me know if you have any more question that I might be able to answer....

[ttweed]

Let me know if you have any more question that I might be able to answer....

Great observations from inside a car on the track, Jad. The car I drove was in TC mode all the time I was in it, and of course I was not able to throw it into a corner and try to accelerate out hard in the paddock, so did not notice the intrusiveness of the software. Sounds like they are trying to protect their customers from themselves in a heavy-handed way. This is what their website says about the subject: "In the Roadster, the motor torque can be accurately reduced either gradually or quickly - resulting in better control with less noticeable loss of power. With onboard sensors, the car predicts achievable traction when cornering before the driver can even command a change in acceleration. It’s much safer to avoid loss of traction than react to it. Expert test drivers have found they are able to achieve higher performance with the Roadster traction control system than in comparable gas-powered vehicles." Either the car you were in was an older model and they have updated their systems, or I would have to dismiss this claim as marketing BS. Maybe they need some gearhead engineers working on the handling side to complement the electronic geeks doing the EV systems. The software is whacked if that's the way the car actually behaves.

Obviously, some stickier rubber and maybe wider tires (with LSD/ARBs. etc.) could mitigate the traction control kicking in, or with enough experience modulating the throttle, one might be able to control the power to the ground better without the need for TC, but my question for you would be what do you think the car would be capable of on yesterday's track with an experienced driver, as far as lap time is concerned? I can only remember noting one Tesla lap time during the day, and it was a 1:14. Considering the range of times we saw, from Erik's usual otherworldly alien 1:00 to a well-driven S/S Boxster time of say, Kim at 1:07, where would the Tesla fall, in your opinion?

BTW, your student's fears of destroying the battery by running it down were due to his inexperience with the car. The battery management system would never allow damage to the pack. The engineers would kick the system into a "turtle" or "limp home" mode when the state of charge became too low, cutting speed, turning off climate control and any other unnecessary power drains, and eventually shut the car down before the batteries could be totally depleted or damaged in any way. The packs are too expensive to risk such a thing. It's too bad he only had a 110V circuit to charge it with too--you really need a Level 2 (240V) charger to get a reasonable charge time with EVs. Ideally, the Tesla can charge completely in 3.5 hours with the right charging equipment, which costs on average about $2000 to install in your garage (but you can receive a 50% tax credit on the installation of the EVSE, or even get it for free if you agree to participate in the EV Project for 2 years like I have done). The L3 (480V DC) chargers that are being installed along transportation corridors for "opportunity" charging of EVs will give an 80% charge in 25 minutes.

Like you, I am very interested in seeing how the S model turns out with the "ground up" development they are investing in it. If they keep it under $50K with all the features they are promising, it will be quite a sedan-type "family" vehicle for the money.

TT

[Curt Yaws]

When I drove the Tesla, the representative put it in Sport mode for me. I'm sure that modified the traction control limits. We did a few spirited runs in the area south of the trolley tracks, and I put the car into a couple of skids where it under steered/pushed noticeably. David, the rep, indicated that the suspension was set up to understeer, but that the suspension was manually adjustable and could be set to a very neutral balance. In Sport mode I never felt TC kick in, though it might have and been a different feel than I would be used to. I did get the sense that you could set up the car to your own happy desires, and it would be wonderful fun. If I just had a sponsor to purchase the car, I'd be happy to sign on as the driver. Anyone?

[sean_v8_914]

they didnt give it a full charge before showing up to a promotional event

[ttweed]

they didnt give it a full charge before showing up to a promotional event

Sean-
Jad explained this in his message. It was one of the private Teslas (not the factory ones) that was actually on loan from a friend (must have been a VERY good friend to flip the keys to a $150K car to his buddy!) The guy who drove it down to the stadium did not really know much about the car (I tech'ed it, and he couldn't answer even basic questions about it), he had borrowed it the day before, run all around in it, and didn't have a proper charging station to put it on Friday night before driving it to the stadium.

Hey--didn't you tell me you are building electric 914s yourself? Any plans to autox one?

TT

[Jad]

I hope either they improved the tc or it gets better in sport mode as it seemed like they decided instead of doing it right, just prevent any problems before they start ala Lexus, very far from the modern Porsche PSM.

I can't really guess on a time, the acceleration was amazing, but handling didn't seem to quite match a Boxster, nor did braking, but 3 laps from the passenger seat with a driver learning a borrowed car, the track, and driving, is so far from optimum, that guessing if the car could go 15 or 18 seconds faster is beyond me. But my guess is the tighter the course, the more the torque would help, the power does fall off, instead of increase, as speed builds (max torque at zero and no tranny). My guess, 1:07 would be very possible driven and setup well, based mostly on acceleration.

The bad news, officially the Model S is up to $60, and probably heading toward $70K according to rumors before it reaches dealers, more with options

[sean_v8_914]

I have assisted in the building of 3 electric 914s but have not completed a build 100% . my customers have been very hands on, wanting the satisfaction of teh build. while they were quick to give me credit saturday, Peter and Richard did a fine job on their cars. both used a totally different system. this spring I am building another and look forward to applying the lessons learned from other builds....fasster and of course, greater range. both of these parameters are governed by budget

[ttweed]

The bad news, officially the Model S is up to $60, and probably heading toward $70K according to rumors before it reaches dealers, more with options

OUCH! I was looking on their website and the page to reserve one says:

Production begins 2012
$5,000 refundable reservation
Base Price: $49,000*
*Price includes $7,500 US Federal tax credit

So adding the $7500 into the base price, it actually appears to start at $56.5K and go up from there. With tax and registration, that will definitely be $60K. If you choose the "Signature Model S" it says "Price and options TBD," with a $40K refundable deposit! So obviously they're giving themselves a lot of wiggle room, and since it's going to be available in three range options: 160, 230, and 300 miles, the base model will undoubtedly have the smallest battery pack, and the long range option will be quite a bit higher.

What I would really like to see is for Renault to tone down the expensive bits and the garish interior in their concept DeZir EV shown at the last Paris show and go into production with it at a sub-$50K price point. I would be a buyer for that car.


TT