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.
