Autocross- SCCA EV-X Class vs. SS

[randmness]

I went ahead and signed up for the National Solo event here in DC this weekend; Looks like I'm the only one in EVX. This is my first National event

Shot from the SCCA Level 1 school here at FedEx Field. Such a blast.

Photo credit: @fromsirus

 

[Fprodget]

Good luck !!
I would go but don’t have my control arms and shocks yet.

 

[gearchruncher]

Has anyone here experienced loss of traction control/other aids with sticky tires?
I moved up to Yoko A052's, and in 30 runs I have had two cases where in the middle of the run, the car beeps, slows for a moment, and shuts off all aids. This persists until I park the car and get out, and then all is fine again. (It's not the ABS wire!). It does appear to happen when the car is very dynamic and could be related to the e-diff or some other control actuating.

Never had this before on PS4S's or old RE71's. HOWEVER, I also switched my 12V battery to a DIY LFP at the same time, and it could be this, which is why I am asking if anyone else has experienced this with just stickier tires.

 

[SK360]

Has anyone here experienced loss of traction control/other aids with sticky tires?
I moved up to Yoko A052's, and in 30 runs I have had two cases where in the middle of the run, the car beeps, slows for a moment, and shuts off all aids. This persists until I park the car and get out, and then all is fine again. (It's not the ABS wire!). It does appear to happen when the car is very dynamic and could be related to the e-diff or some other control actuating.

Never had this before on PS4S's or old RE71's. HOWEVER, I also switched my 12V battery to a DIY LFP at the same time, and it could be this, which is why I am asking if anyone else has experienced this with just stickier tires.

Never even with a number of spins and drifts

 

[MasterC17]

Unless I am missing something being new to the Tesla....there are three choices Super Street, A Street Prep, or EVX. and maybe XSA.....but that Peachey fellow in the corvette is obscenely fast.

I'm running ASP this year; more fun to run with competition too than to be the only one in EV or EVX

 

[MasterC17]

Has anyone here experienced loss of traction control/other aids with sticky tires?
I moved up to Yoko A052's, and in 30 runs I have had two cases where in the middle of the run, the car beeps, slows for a moment, and shuts off all aids. This persists until I park the car and get out, and then all is fine again. (It's not the ABS wire!). It does appear to happen when the car is very dynamic and could be related to the e-diff or some other control actuating.

Never had this before on PS4S's or old RE71's. HOWEVER, I also switched my 12V battery to a DIY LFP at the same time, and it could be this, which is why I am asking if anyone else has experienced this with just stickier tires.

I was going to say the only time I've had that is with an ABS wire that was starting to die but not completely worn though. Do you have any video?

 

[superflyrolla]

Has anyone here experienced loss of traction control/other aids with sticky tires?
I moved up to Yoko A052's, and in 30 runs I have had two cases where in the middle of the run, the car beeps, slows for a moment, and shuts off all aids. This persists until I park the car and get out, and then all is fine again. (It's not the ABS wire!). It does appear to happen when the car is very dynamic and could be related to the e-diff or some other control actuating.

Never had this before on PS4S's or old RE71's. HOWEVER, I also switched my 12V battery to a DIY LFP at the same time, and it could be this, which is why I am asking if anyone else has experienced this with just stickier tires.

Yes! What errors are you seeing?

I've lost regen braking in the middle of autocross runs on more than one occasion. It was especially bad at SCCA nationals last year on 295/30R18 Hoosiers on some real grippy concrete. I talked to MPP about it. They said it was not due to small tire diameter. Overall not that bad, but causes sudden change in how the car reacts.

I've finished autocross runs and realized my my hazard lights turned on. Car must detect something unusual, don't really care.

Last week after a run, I got "front motor disabled, ok to drive" and "vehicle hold disabled." I discovered a little chunk of asphalt stuck between my caliper and wheel, cleared the rock out by putting it in reverse, but on my 2nd run the error came back so I quit racing for the day. Had no issues or errors on the 2 hour drive home. That event was my first on 275/35R18 so now I'm questioning the wheel diameter issue again.

 

[DFW_MVP]

Yes! What errors are you seeing?

I've lost regen braking in the middle of autocross runs on more than one occasion. It was especially bad at SCCA nationals last year on 295/30R18 Hoosiers on some real grippy concrete. I talked to MPP about it. They said it was not due to small tire diameter. Overall not that bad, but causes sudden change in how the car reacts.

I've finished autocross runs and realized my my hazard lights turned on. Car must detect something unusual, don't really care.

Last week after a run, I got "front motor disabled, ok to drive" and "vehicle hold disabled." I discovered a little chunk of asphalt stuck between my caliper and wheel, cleared the rock out by putting it in reverse, but on my 2nd run the error came back so I quit racing for the day. Had no issues or errors on the 2 hour drive home. That event was my first on 275/35R18 so now I'm questioning the wheel diameter issue again.

I had 10 ~58-second runs this past weekend on 275/35/18s, and no additional errors (vs the 12v battery errors that I'm expecting the next Ohmmu battery to fix).

 

[gearchruncher]

No in cabin video, just a through window dashcam. I've looked at my ABS wires and they look fine but that's interesting and I'll double check. When you lose the ABS wire do you drop regen and everything else?

 

[gearchruncher]

That event was my first on 275/35R18 so now I'm questioning the wheel diameter issue again.

Oh, I hadn't considered the tire diameter- I did go from 265/35R19 to 275/35R19.
I'm getting a ton of errors- I guess I need to take a photo next time. I just know the car has no regen, no traction or stability control in this mode, and the power feels like it's reduced (not all bad with TC off!).

 

[Fprodget]

I am curious here. My Falkens are 275/35R19.......which per the tire rack site are 26.6" over all diameter and the OEM tire on my M3P which were 235/35-20 at 26.5"......that should be close enough to not be a contributor to these issues. I have yet to run an autocross as first one here is not till end of April.

 

[gearchruncher]

@Fprodget - I had hundreds of runs on various 265's (and even some 285's) before this, so I bet it's not the diameter. Most likely my crazy 12V DIY battery, but could be the extra grip too. The other local guy on Cup2's hasn't had any issues. I'll have to swap back the battery next time and find out.

 

[SK360]

Prepping the car for the start of the 2022 AutoX season tomorrow. Switched from 265/35/19 RE71R to 265/35/19 RT660, glad I grabbed 5mm spacers because they weren’t lying when they say the 660’s run wider, comparison pics with no spacers at the end.

 

[Fprodget]

Prepping the car for the start of the 2022 AutoX season tomorrow. Switched from 265/35/19 RE71R to 265/35/19 RT660, glad I grabbed 5mm spacers because they weren’t lying when they say the 660’s run wider, comparison pics with no spacers at the end.

View attachment 791842View attachment 791843View attachment 791844View attachment 791845

Here is my clearance with 275/35-19 on wheels with et of 29

 

[SK360]

Here is my clearance with 275/35-19 on wheels with et of 29

What width? These are 19x10 +35

Things look much better once I threw the 5mm spacer in

I’ve been testing stiffer compression/rebound settings on the MPP Sports, I found I really liked how the car felt at 5/5 front and 4/4 rear last season so I went back to it, see how it goes.

 

[Fprodget]

What width? These are 19x10 +35

Things look much better once I threw the 5mm spacer in

View attachment 791884


I’ve been testing stiffer compression/rebound settings on the MPP Sports, I found I really liked how the car felt at 5/5 front and 4/4 rear last season so I went back to it, see how it goes.

My wheels are 9.5

 

[dsgerbc]

Prepping the car for the start of the 2022 AutoX season tomorrow. Switched from 265/35/19 RE71R to 265/35/19 RT660, glad I grabbed 5mm spacers because they weren’t lying when they say the 660’s run wider, comparison pics with no spacers at the end.

View attachment 791845

Looks fine to autox w/o a spacer. Probably a bit sketchy for the street, in case some rock gets stuck on the tread and shears off that ziptie.

 

[gtechie]

Autocross #3 with the SR+ is in the books! The course designers Saturday claimed the course was over a mile long, and the ~80sec runs seem to back that up. It was tons of fun, but also put a ton of stress on the poor car - when a buddy saw the color of my front rotors he grabbed his laser thermometer and got a reading of 399f and 370f on the front rotors! I never had any problems on course, but on the way home realized just how squishy the brake pedal was. Thankfully the regen braking kept us safe. Sunday afternoon, I bled the brakes and put brand new ATE200 in there, verifying the pads have plenty of thickness left. My pedal feel is back to normal.

Tires: I have a set of Nexen N'Fera Sport R tires ready to use whenever I kill the OEM Michelin Pilot Sports, which is happening quicker than expected, honestly. In previous cars I could go an entire autox season on a single set of tires (RE-71Rs, Nexen SUR4Gs, Maxxis VR1, and Hankook RS4s were my last 4 sets in a Miata or S2000) but these Michelins are looking well worn already. My tire wear so far is interesting - the rears are more worn, whereas the fronts generally have more tread left except for the outer edge, which is almost dead. I had been running about 40psi; next event I'll drop the rears a bit more, down to 35-38ish and raise the fronts to 45ish to save the outer edge. What's the go-to answer for front camber, the adjustable upper arms?

Charge: we started our runs with 97% charge, and after 6x2=12 runs (no reruns) we finished with 55%. It was just enough to keep us above the magic 50% mark, at which we start feeling a loss in acceleration.

Steering: I'm learning how to drive around the stability control - basically, if the wheel is turned you might as well not hit that pedal because it won't go yet. Turn, straighten the wheel, then hit the fun pedal. I used to be able to trailbrake and start to accelerate as I start to unwind the steering wheel, so I'm having to unlearn some of that. I've toyed around with the idea of buying a Party Box, but I want to learn the car first.

All in all, I'm loving this silly car!

 

[gtechie]

Sorry for the double pictures, I'm not sure what I did to cause that.

 

[dsgerbc]

What's the go-to answer for front camber, the adjustable upper arms?

Yeap.
At some point someone was planning on making offset camber bushings for the lower control arm, but I don't think anything came out of that.

If you're dead set against non-OEM upper arms, you can gain some camber by lowering, a hair more by loosening everything in the front suspension and re-tightening while trying to utilize the available slack in favor of more camber, and, finally, by extending the bolt holes for the front shock tower bracket to move it inwards a bit.
The latter involves the same amount of work as swapping the arms.