Autocross Setup for the ZL1

[ZL1_TA]

Curious who has had their ZL1 on the autocross track and what setup you are using? I am new to autocross but have tried a few in my ZL1.

I typically run in PTM mode 5, 40psi in the stock tires. Have been running in 1st gear but sounds like I should be using 2nd.
Even in the PTM modes the car looses traction easily on the course and I am sure running in 2nd will be a lot smoother.... going to try this next time.

Would like to hear about your experience and car setup:

Everything off:
PTM on/off:
PTM Mode:
Tire Pressure:
Gear:
Others Info:

Tony
2013 ZL1 M6

[prostcj]

Haven't autoxed the Zl1 but I would say for sure 2nd gear. Also, 40 psig sound like a lot of pressure. Usually you would run a little on the low side for the most traction.

[Stoneb1]

I ran in ptm4, and for sure in 2nd gear. I started with tire pressure 35-36. If you are still on the stock Goodyear tires, then you are going to have trouble with traction in auto cross. They are pretty good on a road course where you can get some heat in them. In auto cross, not much chance to get them up to temp.

[ZL1_TA]

Typically they recommend 10psi above standard for autocross from what I understand and given the car is so heavy maybe even more would be better?

Still running the stock tires and they are definitely slick when cold but around corners they seemed to hold ok it was the suspension that seemed be
limiting. Acceleration is a different story... very poor when cold but the PTM modes help out a little... coupled with running in 2nd I am guessing there
will be enough traction accelerating out of the corners... just need lots of seat time to figure it all out...

[Nor Cal ZL1]

Tires that are over inflated are just as bad as those that are under inflated. The 10 PSI is a little bit old school tire with high sidewalls. I can't say what the best tire pressure would be, but I would adjust it in the Autocross environment, so that the wear is just to the outer edge of the tread. The GY's probably won't get warm enough in that environment due to the short runs. The higher the pressure the cooler the tire will run.

[pumpkinrancho]

Everything off:
PTM on/off: on
PTM Mode: 4
Tire Pressure: 26
Gear:1 or 2 depending on length of the course, I try it in first and only shift if I hit the rev limiter
Others Info:
tire wise you are supposed to let the tires decide what air pressure. Take a run and look at the little arrows on the sidewall. If the tire scrub is not reaching the arrows let more out till it does. The tires are designed for this. Saying this the best times you will achieve in the autocross will not be with the factory goodyears. I am replacing with Michelin Pilot super sport k2s. Other hot tire currently is the bfg g force rival.

[Novie LE]

I would start with 35 front and 33 rear cold. I have been using around there with my 1le and it works great. As for which gear to use. My advice would be to shift out of 1st gear as early as you can and leave the car in 2nd gear.

[littlebuffalo]

Originally Posted by Novie LE

I would start with 35 front and 33 rear cold. I have been using around there with my 1le and it works great. As for which gear to use. My advice would be to shift out of 1st gear as early as you can and leave the car in 2nd gear.

I agree, except the front pressure. I run about 32-34 on all 4. If your sidewalls are rolling over a bit much add pressure, if they aren't at all, lower some pressure. With a zl1 a bit heavier on the front try a couple pounds more and work from there. 40 is way too much in my opinion. Grab 2nd gear asap, the zl1 has plenty of power for most autox courses even though the butt dyno says otherwise, shifting gears loses time.
Finally use race mode 5, it gives plenty of wiggle room but should save you in a bad situation.

[ZL1_TA]

Thanks for all of the advice so far... keep it coming! Never knew what those little arrows were for on the tires... I was definitely not hitting those.

Curious why some are running PTM 4 vs. PTM 5. I think PTM 5 uses stiffer suspension so it would be the best choice... I only tried PTM 3 and decided to move to 5 after 3 seemed to be way too restrictive when sliding the car a little...

Thinking I will try 35psi in the fronts and leave the rears at 32 to start with next time.

[jksynergy]

I can't help you with the ZL1 traction control suggestions, but regarding the tires, I have a 1LE, I've found 33-34 all the way around to be good for autox. My last runs the outside temp was high 80's and the track was plenty warm when I started in the 2nd heat at noon. No sidewall roll over or movement from them. I mark the sidewalls and my marks had very little rub off on them. Good luck, and have a blast!!!!

[mgue67]

I have a vert so less options. I run in second the full course. I have never topped out. I was running lower pressure mid-30's but went threw a set of tire very quickly. I have since went to BFG's and running 40. I like the feel and the wear is much better.

[ZL1_TA]

Originally Posted by mgue67

I have a vert so less options. I run in second the full course. I have never topped out. I was running lower pressure mid-30's but went threw a set of tire very quickly. I have since went to BFG's and running 40. I like the feel and the wear is much better.

I tried 33 in the front and 31 in the rears at the last Autocross. Seemed to be just right... could see where I was getting close to the arrows on the sidewalls but did not touch them. The course was faster than normal hit the rev limiter in 2nd on the first run. Definitely will upgrade the tires when the stock tires wear out. Don't like how they are so slippery when they are cold. Luckily it was a hot day so they weren't too bad out there but still could have used more traction on most of the corners... Used PTM 5 again but wish I would have tried everything off for a run... think having full throttle response on the fast course would have helped... just not sure how much the suspension would hurt in sport vs. race? Which BFG's are you running?