Model S (Performance edition) 1/4 mile time

[rabar10]

Here are some more Roadster timeslips:

These two slips really tell the story of EV drag-racing, at least for Tesla EVs.

Up through the first 330 feet (1/16mi), the two runs are nearly identical (0.1% time difference). This track section is completely torque-limited for the Roadster.

At the 1/8mi, the times are still very close (0.3% difference) but the slip on the right is almost one MPH faster (0.9%) at that point. Then by the end of the 1/4 mile, we have the final times different by 0.07 sec (0.5-0.6%) and speed different by 1.7MPH (1.6%).

Note that the earlier slip had the best time, and the runs are only 6 minutes apart. The car certainly wasn't recharged between runs.

So ignoring other differences like real-time wind speeds, steering corrections, etc., when the car is under full acceleration and gets up into speeds where it becomes limited by battery current instead of motor current, the slightly lower battery voltage in the second run reduced the max power of the car by just a bit in the last half to three-quarters of the track.

Tesla EVs are perfect for bracket racing. So smooth, consistent and predictable.

Requisite Model S prediction: 13.88

 

[Dan5]

Reaction time is not included in the times on all time slips I have, they are time runs based on breaking the starting line beam. I believe that is the case on these as well.

Yeah, reaction time is what I would like to know, that way I know the "level" of the driver, at least on normal cars it's kind of a good qualifier to determine the quality of the driver for drag racing. A very good driver will have a great reaction time which means he/she knows how to drive the car correctly for the 1/4 mile.

The first time I took my car to the track, I did 15's, the car was capable of mid 12's, I've witnessed it going mid 12's- I've gotten better, but have yet to break 13.0.

Point is you need that to determine the who was driving and if they were perfectly pushing the car to the maximum performance. Driving a car perfectly for 1/4 mile is a difficult task, no fishtailing, perfect track, no spin outs, not just completely flooring it, no hesitation, it slips for a split second and your time is screwed up- it's an art form, that's why my gut says the roadster is capable of 12.6 or less

 

[Robert.Boston]

Color me ignorant, but with a Roadster (or a Model S), why isn't the correct strategy to floor the accelerator throughout? The TC will ensure that the wheels never slip.

 

[smorgasbord]

isn't the correct strategy to floor the accelerator throughout?

A'Yup.

 

[vfx]

Better than human. Even the Stig?

 

[TEG]

Color me ignorant, but with a Roadster (or a Model S), why isn't the correct strategy to floor the accelerator throughout? The TC will ensure that the wheels never slip.

That is what was being done on those 1/4 miles runs I posted.
As was said, the Roadster is awesome for "bracket racing" as it is easy to get quite consistent times from run to run. ("So easy almost anyone could do it.")
Some time difference can be had by other factors, such as lighter weight driver, folding back the rear view mirrors, etc.
The real differentiator is launch technique... Reaction time - brake/accel pedal transition.
Is the best way to go with traction control turned off (although "off" is supposedly not 100% off), and hold the brake pedal and accel pedal both down at the same time, then release the brake when the "tree" light goes green? I heard some debate as to the best pedal technique for best launch.

 

[qwk]

Yeah, reaction time is what I would like to know, that way I know the "level" of the driver, at least on normal cars it's kind of a good qualifier to determine the quality of the driver for drag racing. A very good driver will have a great reaction time which means he/she knows how to drive the car correctly for the 1/4 mile.

The first time I took my car to the track, I did 15's, the car was capable of mid 12's, I've witnessed it going mid 12's- I've gotten better, but have yet to break 13.0.

Point is you need that to determine the who was driving and if they were perfectly pushing the car to the maximum performance. Driving a car perfectly for 1/4 mile is a difficult task, no fishtailing, perfect track, no spin outs, not just completely flooring it, no hesitation, it slips for a split second and your time is screwed up- it's an art form, that's why my gut says the roadster is capable of 12.6 or less

Reaction time doesn't matter, and rarely tells you what the driver is capable of. While It's harder to get the best times out of a stick shift car, the roadster has only one gear. Unless you screw up the launch(hard to do), your only other variables are battery temp, state of charge, t/c on/off. With that being said, I agree that a better time is possible, but it will probably take some tweaking like altering the gear ration through taller tires etc.

 

[smorgasbord]

Is the best way to go with traction control turned off (although "off" is supposedly not 100% off), and hold the brake pedal and accel pedal both down at the same time, then release the brake when the "tree" light goes green? I heard some debate as to the best pedal technique for best launch.

If you can be rolling just slightly forward, then I'll bet the best is to be in neutral, hold the accelerator down, and simply punch the "D" button (v2.0 & later). I guess that's called a rolling start, but you can be moving even less then 0.5 MPH I believe. It won't work if you're stationary.

When I take people for rides I do a California Sushi stop, go into neutral and press the accelerator down. Then I ask the passenger to hit the "D" button. It's alot of fun.

 

[cinergi]

Without doing the math, I feel like we're seriously under-estimating the Model S. While the sport is 4.4s 0-60 and 4,000 lbs (theoretically), it has *WAY* more power than the Roadster (which will be a huge bonus above 60 MPH).

 

[Doug_G]

If you can be rolling just slightly forward, then I'll bet the best is to be in neutral, hold the accelerator down, and simply punch the "D" button (v2.0 & later).

Will it switch to D if you're not holding down the brake?

 

[spatterso911]

... traction control turned off (although "off" is supposedly not 100% off), and ....

do we know how the traction control is set up on the S? Is there a different TC logic for the Perf? My M5 has 3 settings, On, Partial TC, and off. Even with the relatively low torque and slow onset of max torque for the M5, it is ill advised to floor it with TC off, as the rear end can go loose and ruin your run. This car has max torque at go, so I wonder if they would ever give us an option to completely kill the TC.

 

[TEG]

With the Roadster at least, it seems like Tesla designed in some amount of tire preservation and "gentleman's sports car" behavior where it really doesn't want to wildly spin and smoke the tires even with TC in the 'off' position. The one speed gearbox doesn't multiply torque the way something like the M5 would. In exchange for seamless power delivery (no shifting) you have to give up some of that "beastly" behavior you can find in some other supercars.

 

[spatterso911]

Is there a reasonably accurate idea of the torque on the S Performance? or the S (85)? I wonder if there is a power curve plotted out somewhere ...

 

[ggr]

Will it switch to D if you're not holding down the brake?

Yeah. You need the brake to get out of P, but you can switch from R to D with no brake, even while rolling slowly backward. If you're rolling too fast you get an error message "Unsafe transition denied". Make sure it actually switches before flooring it!

 

[Doug_G]

Interesting... will have to tinker with that.

 

[smorgasbord]

U

Make sure it actually switches before flooring it!

No need to, at least going from Neutral to Drive - that's the whole fun of it.

 

[TEG]

If you're rolling too fast you get an error message "Unsafe transition denied".

LOL... So 'matter of fact' and technical... Part of me wishes it said something like "Don't be an idiot", "The car will break if you do that!", or "Abort! Abort! Danger Will Robinson!"
Well, OK, more like "Reverse speed too fast to change into Drive..."
I guess they have limited space for error messages, so have to be creative with the short wording.

 

[brianman]

"I'm sorry, Dave. I won't do that, you retard."

 

[ggr]

No need to, at least going from Neutral to Drive - that's the whole fun of it.

Yes, I agree; I meant switching from R to D or vice versa.

 

[GSP]

....What I am really interested in is the skidpad results! I'm betting that those are truly impressive!! >1.0 g ?

I am not an expert, but if I recall correctly skidpad G results are almost completely determined by the tires selected, as long as the chassis is at least reasonably well set up. So I am not expecting anything out of the ordinary for the Model S.

However, the low Cg will make actual driving extraordinary, with very little body lean in corners, also low squat and dive when accelerating and braking. The test results most affected should be slalom speeds and emergency lane change maneuvers. Actual everyday driving will be much more impressive than the numbers, making the "EV grin" even larger - as hard as that is to imagine!

GSP