SCCA Autocross Class for the Model 3

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#1
SCCA released their revisions for July and the Model 3 now has a proper classification.

D Street:
https://www.scca.com/downloads/41816-2018-07-30-solo-rules-book-2e-reduced/download
Page 150.

Seems fair to me for the TM3 LR. However, it doesn't differentiate between the LR, Dual Motor or Performance. If they don't correct this in time for Nationals, a P3D owner with a little skill might want to consider giving it a shot.
 

tencate

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#2
What about 2017 models?
 
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#4
Jumping in here because I recently learned about SCCA and autocross as they were hosting a Solo event near my home. Seemed like great fun and I've been looking into trying it out. However, in my research, I see that Tesla's warranty does not cover vehicles used for autocross or racing.

Is this a concern for anyone using their Model 3 for autocross?
 

JWardell

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#5
Jumping in here because I recently learned about SCCA and autocross as they were hosting a Solo event near my home. Seemed like great fun and I've been looking into trying it out. However, in my research, I see that Tesla's warranty does not cover vehicles used for autocross or racing.

Is this a concern for anyone using their Model 3 for autocross?
I highly encourage anyone to try an autocross, it is the best way to learn how your car handles and drives, and is a ton of fun without the dangers and wear of real racing. Speeds usually don't even hit highway speeds. Something I used to do regularly in the old days and I very much miss it!
 

BostonPilot

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#6
Driving over uneven, rough, damaged or hazardous surfaces, including but not limited to
curbs, potholes, unfinished roads, debris, or other obstacles, or in competition, racing or autocross or for any other purposes for which the vehicle is not designed;
Interesting that they call that out. Not really sure how they can enforce that... Especially the M3P+ with "track mode".... It would be pretty difficult for them to claim it wasn't designed to be used on a track!
 
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#7
Interesting that they call that out. Not really sure how they can enforce that... Especially the M3P+ with "track mode".... It would be pretty difficult for them to claim it wasn't designed to be used on a track!
I know, and I'm sure my car would be fine, but I get nervous when they're calling autocross out specifically.
 
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#8
Notes from my first outing on June 23rd:

Sent: Tuesday, June 26, 2018 6:48 AM
Subject: AutoX-ing a Model 3 : Experiment #1

This past weekend I took the Model 3 out to a **** practice day. I didn’t know what to expect from it but I was optimistic. The setup is essentially stock with the only change being the wheels and tires (both stock sizes):

Wheels: Enkei Raijin, 19 x 8.5 +35mm
Tires: Continental Exteremecontact Sport, 235/40-19 (next step up from the 19” OEM Continental Procontact tire)

I charged to 100% the night before and drove down to ******* in the rain arriving w/ 72% charge from my place in ******. It’s worth noting that if I had been on the OEM tires w/ the aero caps I probably would have been able to get there with more than 75% charge. I’ve noticed a 10% decrease in efficiency from the OEM tires to the tires I have on now.

We ran a semi-Enduro course. The course was setup for Enduro but we only got one hot lap instead of 3. Because of this format one run of this course was equivalent to two runs of a standard auto-X course with only the last one timed. It was the usual; slalom-slalom-slalom…, u-turn, slalom-slalom-slalom…, u-turn course typical of the runway at ********* Field. It was the course from the previous weekend’s auto-X competitive event and seemed to favor the higher horsepower vehicles. It flowed well with 4 distinct hard braking zones. I recall seeing 67 mph while at one of the faster points on the course.

The weather was in the low 70’s overcast to partly cloudy and dry. There were about 22 cars present in the AM. I ran in the 2nd run group and had a chance to observe the times of the 1st run group noting several cars where the vehicle type and driver skill seemed to match mine. Two(2) F-chassis 3-series Bimmers and one(1) newer Mustang (V8, possibly a GT). For the most part other than exhaust they seemed stock to me. I didn’t know the drivers but from what I could tell, they weren’t novices to auto-X. Collectively their best times for the session were roughly in the 57-58 second range. Times were not recorded that I know of only announced via the PA system.

Run 1 (lap 1 & 2): I attempted to create a baseline and familiarization with the course and the car at the limit.
- SoC at start: 72%
- Tires Front L/R : Rear L/R (psi): 47/47 : 44/44
- Steering Mode: Sport
- Regeneration: Standard
- Slip Start: 0ff
- Time (sec): 59.8 / Clean
- Watt-hours/Mile: 1,206
- ESC was noticeable in some instances

Run 2 (lap 3 & 4): I attempted to push harder.
- SoC at start: 69%
- Tires Front L/R : Rear L/R (psi): 50/50 : 45/45
- Steering Mode: Sport
- Regeneration: Standard
- Slip Start: On
- Time (sec): 58.3 / Clean
- Watt-hours/Mile: 1,250
- ESC was more noticeable especially when attempting to rotate of the car with the throttle.

Run 3 (lap 5 & 6): I attempted to find a better line that the ESC would like.
- SoC at start: 66%
- Tires Front L/R : Rear L/R (psi): 50/50 : 45/45
- Steering Mode: Sport
- Regeneration: Standard
- Slip Start: On
- Lap 6 Time (sec): 56.9 / Clean
- Watt-hours/Mile: 1,324
- ESC was not as noticeable in some instances

Run 4 (lap 7) with a passenger: standard autoX
- SoC at start: N/A
- Tires Front L/R : Rear L/R (psi): N/A
- Steering Mode: Sport
- Regeneration: Standard
- Slip Start: On
- Lunch runs - No Time
- Watt-hours/Mile: N/A
- ESC was very noticeable especially when attempting to rotate the car with the throttle.

Run 5 (lap 8) with a passenger: standard autoX
- SoC at start: 63%
- Tires Front L/R : Rear L/R (psi): N/A
- Steering Mode: Sport
- Regeneration: Standard
- Slip Start: On
- Lunch runs - No Time
- Watt-hours/Mile: 1,327
- ESC was as noticeable in some instances

Observations:
- Camber challenged suspension or the sidewalls of the tire are too soft. I inflated them to the max (50 psi) and I was still exceeding the tread contact surface.
- The car did not roll as much as I expected for a stock car even in the high transitioning sections
- Quick suspension for a stock car
- Braking:
o Strong and linear
o Never got soft, remained consistent
o The ABS does not feel like a traditional brake booster powered brake. There is no ‘farting’ when it kicks in. It’s hard to perceive.
- Steering:
o A little numb, at times it felt like I had a reduced tactile feel of where the tires were pointed
o Steering ratio is quick, works well, very little need for steering shuffling
o Steering wheel size felt good for quick movements
- Power delivery once you get rolling is linear and strong, I could not feel a difference in power from the first to the last run
- Electronic Stability Control:
o Womp, womp… To me this seemed like the biggest weakness.
o Turning on Slip Start is the most that you can do to disable some of the traction control, but my understanding is that it only works at very low speeds.
o The car could be considerably faster if it could be allowed to yaw a little more. It would not allow me to rotate it with the throttle through the corner. On my 2nd to last run (lap 7), I attempted to put the throttle to the floor right before the exit of a 270 degree right corner. The car should have swapped ends but instead it reduced the power and applied some rear brakes.

My friend ***** was there with his lightly modified 2006 Subaru STi, we are equal in skillsets, gauging my performance against his was a good comparison. His STi usually runs the comparable times as my 350Z (lightly modified) when we both are at an autoX. His best time was in the low 57’s.

Near the beginning of my 3rd lap (run 2) I heard very audible “thump” from the driver’s side front during a hard braking event. I thought it might have been a piece of runway coming up and hitting the inside of the wheel well. After my run I checked out the car it and it turned out that the windshield washer cap had popped off and washer fluid went everywhere. It had either not been closed properly or it’s a design flaw that could happen when the fluid is forced forward during a heavy braking event. I secured it and it didn’t happen again, quite possibly because it lost nearly half a gallon of fluid.

There will be another practice on July 7th. Hopefully it will be a regular auto-X so I can record more laps, get some video and try different things. I have to start considering an altered line around the course where I can get more time and distance to help rotate the car for faster times (due to the ESC). I won’t attempt the ABS disconnect trick as it wouldn’t be considered stock class eligible if I did and also for the concern that it could start logging errors and/or reporting back to Tesla what’s happening.
 
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#9
I know, and I'm sure my car would be fine, but I get nervous when they're calling autocross out specifically.
No worries, the car can handle the occasional autocross just fine. The OEM tires however... well... they were never very good to begin with.

It'd be great if you could share your experience and data from the event so we all can benefit from it. The more people that do performance events w/ their TM3's and share their learnings, the better we grow as a community. "Racing improves the breed." - Soichiro Honda
 
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#10
Notes from my last outing on Sept 15th:

This past Saturday was the last **** practice day of the summer and probably for the year for me. The weather was overcast with periodical light drizzle typical of this time of year. Ambient temperature was in the low 60’s for the entire day. The course started out damp but was, for the most part, dry for the day. We were able to keep a dry line even when it began to drizzle by having cars run in through lunch. It was awesome to see **** come out with his TM3 on (T Sportline?) spring, running on the 18” OEM wheels and tires. I’m looking forward to reading any write-up he or ***** do on their experience.

The course ran clockwise with the cross-over coming at the end. There were 4 distinct hard braking zones. The top speed that I was able to observe was 63 mph on the speedo. It was a very ‘technical’ course. It was later reconfigured for the PM to avoid some rough spots and after a Miata driver stated that it was even too tight for his car. It was so tight in some places that a 5-series Bimmer could not make it through one element without coning regardless of speed. I ran w/ my tires inflated to F: 50 psi, R: 40 psi, attempting to keep them in that range.

AM Session, 1st Run Group
Run / Time / Notes / SoC after run (%)
1 / 72.89 / Damp course, 1st car out, recon run / 70
2 / 68.58 / /
3 / 67.46 / Lift oversteer attempted /
4 / 69.72, + 1 gate / Driving ****’s car /
5 / 66.62 / /
6 / 66.16, +1 cone / /
7 / 65.87, + 2 cones / /
8 / 67.25 / /
9 / 66.67 / Wiper fluid cap popped open / 54

PM Session, 2nd Run Group
Run / Time / Notes / SoC after run (%)
1 / 62.606 / / 53
2 / 62.710 / / 51
3 / 62.760 / Loose towards end / 49
4 / 61.592 / / 47
5 / 62.100 / / 46
6 / 61.073 / / 44
7 / 61.264 / / 42
8 / 61.154 / / 40
9 / 60.625 / / 38

The main difference from the AM to the PM session was the changes in the course. It was quicker after some elements were softened to allow bigger cars to get through. In addition, there were half as many cars in the PM session (AM: 10 cars/group, PM: 5 cars/group). Once you were done with your run in the PM and self-logged your time, you were back in the queue. You never really parked in the grid.

Times were not announced over the PA but I was able to do timing on the 2nd run group of the AM. Out of the 10 cars that ran that group, only 3 cars were faster than mine. Two(2) modified Miatas, one being driven by **** (who happened to get FTotD for the AM session) and a Porsche Boxster (non-S, stock-ish) all driven by experienced drivers. Of the remaining experienced drivers in that session; 2 newer 3-series Bimmers, a BRZ and a MK4 Supra all ran slower times. ***** (****’s buddy) ran a 67.XXX in his TM3.

For the AM session *****’s (black STi) best clean run was in the 68.5 range. I use ***** as a comparison since we have about equal skillsets and we would run very close times when I’d run my old 350Z.

The Continental Extremecontact tires I run are decently grippy despite carrying a 320 tread wear rating, but their sidewalls are pretty soft. After Saturday they were looking a little ragged but still have plenty of tread. In their current condition they’re showing a reduction in range as well as becoming considerably louder. They might be better suited for a lighter vehicle. The next tires will have to be ones with stiffer walls if they will be used for daily driving and auto-X use.

**** gave me a good tip. Having owned a Lotus Elise he was familiar w/ throttle lift oversteer. I was only accustomed to throttle on oversteer (only autoX-ing FR cars) but the TM3LR is balanced like a MR. When applying throttle lift to rotate, where it was applicable, it definitely helped. I also noticed that the regen could be used to your advantage by causing the back end to drag helping to recover from an understeering situation better.

For the most part, the challenge of the day was trying to find a line and inputs that the ESC would be happy with. It is, IMO, the current weakest link to overcome to make the car faster around an autoX course is the ESC. Prior to the practice, I experimented with the ABS disconnect. While the increase in power and the ability to throttle oversteer at will were great, the heavy steering, increased braking effort, lack of rear braking from regen and no ABS seemed like it wasn’t going to yield any faster time for this course. Brakes were used so heavily that the whole grid area had the strong smell of burnt friction material. Everyone left that day with blued rotors even if you only did the AM. In the PM session instead of just getting back into the queue, I would drive down the access road into the pits and then back for some brake cooling. I should probably bleed the brakes, there was a hint of the pedal getting long in the PM session. Surprisingly there seemed to be no significant loss of pad thickness after a brief inspection.

Something that I was concerned about was the SoC and how much power loss I’d experience. From 70 – 38, I would not have been able to tell the difference on any of my runs. Referencing the data that Mountain Pass Performance collected, it seems that torque as speed up to 30 mph there is no difference in torque from 15 – 90 SoC and only a 18% drop over that range. At 38 SoC I think it probably would have been no loss of torque up to 35 mph. My fastest time in the PM session was my very last run indicating that, at least in autoX, SoC is not a significant factor in performance as long as you’re not below 20%. Probably would be more noticeable on a track.

I got home with 7% charge. Plenty to spare. I charged for 45 minutes at ****** ****** ****** at their L2 in the morning on my drive up arriving at ********* Field a 72% SoC. Once the ******* Superchargers come on-line it may be possible to arrive in ******* with 90% SoC without spending a lot of time charging.

Lastly, that silly wiper fluid cap popped open again. It feels like a positive lock when I close it, but it opened up again and spilled wiper fluid. I think it may be associated to the air pressure increasing inside the bottle as components of the car heat up adding to the force of fluid being pushed forward under braking. Or it’s a hidden feature where if the frunk is removed, ta-da… instant radiator sprayer.
 
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