Autocross

[ViperBite]

There is a charity event (autocross) next Sunday I will be running in for fun. With stock tires, what cold pressures do you recommend front/rear? I figured this would also be a quick way to learn more about the car at some low speed limits.

For those in STL it is at the Family Arena on the 4th. This is a non-points event.

 

[1TONY1]

Probably stock pressures. My stock pressure is 26psi cold....I would start there and keep it there when warm. Maybe 1 or 2 psi higher in the front.

 

[Fred(DrivingSchool)Kinder]

Start with 35-38 psi and adjust from there by looking at the tire edges excessive roll add psi.

Skip Barber runs their Vipers in the high 30's at their autocross portion of the school.

 

[Jeff-00-ACR]

I usually run 28-32 in the Pilots and check the edges for roll after each run. If you have scuffing on the sidwall then go up in pressure. Usually won't have to at that pressure. You want to run a low pressure but without any tire roll. You can put small chalk marks on the edges of your tire to help see the scuffing.

Here is a funny video of me losing it in a corner and making some smoke...
Autocorss smoke

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[Steve 00RT/10]

I've found 47F/44-45R to work well.

Steve

 

[ViperBite]

Jeff, how did you mount your camera in the car? Also what did you use to display your number. I would say you smoked em, too bad the doughnuts don't count.

Since this is a once or 2 times a year deal for me, I may just get some legal size paper and tape it on. I am going to run novice class. I have autocrossed in my miata and cobra several years ago. Hopefully it is like riding a bike.

Well I have seen everything from 26-47 psi. I think I will start at 34/34 front/rear.

 

[Jeff-00-ACR]

I got a piece of plexiglass about a square foot and drilled a hole in the center. Bought a cheap tiny tripod and took just the top part off and bolted it to the plexiglass. Then put just the hook side of velcro on the plexiglass. It grabs the carpet perfectly and the whole thing removes easily.

The numbers are a paper number sign taped on with painters tape.

The doughnuts were fun and no biggie since we got 7 runs that day.

Just a reminder that you want your tires to have lower pressure. The harder your tires are, the less flex they will have, and the more they will tend to want to slide. But not so low that they roll. Which is easily seen by scuffing on the sidewalls. It won't scuff the sidewalls very much, but if you have some then go up on the pressure. If you start high on your pressure and you don't see any scuffs then you can try dropping a pound or so on each run and check your tires again.

More Autocross pics