What is the best tire pressure for track?

[Hutash]

I will be driving Buttonwillow raceway this weekend. Temps tend to be high. 95-105F air temps, track alot hotter. I am runnimg Mich pilot sports on my TT 225 quattro. Normal tire pressure is 35psi front and 32 in rear. I am not racing, just having fun pushing the car. Everybody at the track has differernt opinions on the proper pressure for hot verses cold days etc. and the range all over the place. Is there any good rules for adjusting pressures for track/autoX driving?

[Oscar@tirerack]

There really is no guide lines. I would see who else in the padock is running something close to your car/tire combo and compare driving styles. From that, inflate to a few pounds more than what is listed on your door panel to start with, and adjust to what you feel once you have the tires up to track temp.

[Hutash]

Thanks. That is about what I figured, hence the reason there are so many, varible opinions.

[rex_racer]

actually ure starting temps aren't too bad. assuming u'll be doing continuous laps, the tires should end up warming up quite nicely to a decent level. besides what oscar said, u should also chalk up the sidewalls of ure tires in 3 or 4 spots. check out how the tire is rolling over and add or subtract lbs based on that too. and watch the temp of the tire across the tread to help w/ ure decisions as well. but if this is an open learning how to track event, don't be afraid to talk to other ppl, they will be very very willing to help out the new guy .

[Hutash]

How do you measure tire temps? It is likely to be a hot day, and I am concerned about over inflation. I have heared alot about marking sidewalls, and I get the general principle, but I am not sure just how to interpret the info gathered. As for talk with the other drives, I have heard so many differnt opinion that vary by 10 psi that it is hard to know who knows what they are talking about.

[rex_racer]

Originally posted by Hutash
How do you measure tire temps? It is likely to be a hot day, and I am concerned about over inflation. I have heared alot about marking sidewalls, and I get the general principle, but I am not sure just how to interpret the info gathered. As for talk with the other drives, I have heard so many differnt opinion that vary by 10 psi that it is hard to know who knows what they are talking about.

tire temps can be measured by purchasing an infrared heat gun. u pt and shoot and it tells u the temp. i think raytech makes temp gauges, but i forgot if i'm thinking of the right name or not. u can also just do the palm test, though its a lot less accurate u can at least get the general feel of the tire and see if the edges are warmer, or if the center section is warmer. warmer sections means more air is in that area. so if its hot on the edges u probably don't have enough air and if its hot in the center u mite have too much air.

as for the chalking. just look at how much chalk wears off, if its all gone, then the tire is rolling over a LOT and u probably need a few more lbs of air to stablize the sidewall. if none of it is worn down, even the very top edge where the tire shoulders are, u mite be able to remove a lb or so to get more bite from the edges of ure tires.

even though ppl mite give u very vague info or super varied answers, its still good to talk to them. it doesn't mean u have to take their advice, just see what other forms of logic are out there and what made them come to that conclusion. then u can compile all that info and formulate ure own opinions.

remember if ure gonna be starting at low pressure in hopes of letting heat increase the temp, make sure u take it easy for the first few laps so u dont' lose control of the car. oh and if this is ure first time, don't be fiddling too much w/ tire temps and tire pressure, concentrate on learning the line and getting a feel for the car. make minor changes, don't be drastic and keep a lil log book of all the pertinent info, like air pressure, time of day, track temp, air temp, lap speed and ure general feel for it. but most of all HAVE FUN!!! don't be concentrating on all of this.

[Hutash]

Thanks for the info. That is what I am looking for, some simple stright forward tips that make sense. I have been on the track several times, but still have so much to learn. I don't want to get to anal about all this info, but these are so great easy to follow tips.

Thanks again, I am running at Buttonwillow in California on Sunday, so I will put it to use.

[rex_racer]

Originally posted by Hutash
Thanks for the info. That is what I am looking for, some simple stright forward tips that make sense. I have been on the track several times, but still have so much to learn. I don't want to get to anal about all this info, but these are so great easy to follow tips.

Thanks again, I am running at Buttonwillow in California on Sunday, so I will put it to use.

haha sure sure, most of this is just simple logic, i mean if u think about it u can figure it all out its pretty simple. hav fun on the track and remember, fun and safety first!!!