Contour Enthusiasts Group Archives Forums General Autocross and Open Track Autocross - Tyre Pressure

On the topic of door stickers, if you arent running stock size tires they no longer apply. My 18s are 40-42psi every day.

And yes, most people air up on track days to avoid the rolling over the sidewall. Here is the trick. If you dont have access to air while at the track, put a bit more air in your tires than you think you might need. Now, rub some chalk on the outer 1" or so of tread, and a bit down the sidewall (on the outside edge). Now go out on your first run.

If the tire is overinflated, there will be some chalk left on the edge of the tread. If underinflated, some of the chalk will be missing from the sidewall. Good inflation will remove the chalk from the tread, but it should still be on the sidewall. Simple enough?

The tyre chalk is a good thing to do, that will tell you a lot about what your tyres are doing. I almost always do that.

The air tank we have is small so i try to have enough pressure in the tyres and only use the tank to tweek the pressure, or if you are at an open track event and you have let a lot of air out when they were really hot, when they cool down you might not have enough to go home, the other reason for the air tank.

The next autocross is a two day event, the first day is test and tune, the second day is the race. That should give me a good day to set the car up for the race.

For day to day street use, i run 35 psi all around.

The autocross is at Grand Valley State Unversity July 1 and 2. It is being put on by the Furrin Group, not SCCA. West Michigan SCCA, doesn't do much in autocrossing anymore and that is too bad, they are only holding two this year, one at in K-zoo at Wing and one at Gratten Raceway.

A few of us are talking about going to G-man in july some time.

We go to Gingerman about every 3 to 4 weeks, so next time should be about 2 or 3 weeks away. I will post on here and in the W. Michigan section next time we go. And if you go, make sure you let me know, if i don't run, i will for sure be there.

Are you going to the SVTOA event there, or anyone else for that matter?

I would like to, in the process of moving and changing shops soo money and time will tell

I've always considered the psi on the door stickers to be crap. Even with factory sized tires and stock suspension. It's an averaged (one size fits all) specification that leans more towards squishy than stiff. "One size" rarely fits "all".

On stock suspension with almost stock sized tires, I prefer 38-front, 34-rear.