az55

I'm running HPDE3 and Time Attack this Sunday at PIR. Temps in the morning 45degrees, afternoon low 70's. Should I start at 30lbs all around or 32/30 front/rear? I have 18" wheels all around and Kumho MX tires. Shocks are Koni dual adjust. It's my first run with this car, a 2002 ZO6. Any thoughts?
Cheers from Arizona.

wtknght1

Are you to the point in your driving where you can tell the difference between 2 lbs?

Have you run these tires before? If so, where did you start?
Suspension settings - camber??

Normally the fronts need a bit more pressure than the rear, but whichever you go with, take good notes and annotate all changes and how it affected the car/driver.

When/if you get a chance, find a pyrometer and take some tire temps and then adjust accordingly. Talk to your instructor before, during and after! You're there to learn, so don't get too caught up in 1 or 2 lbs of pressures here or there...not yet anyway.

Good luck!! Have fun!!

Lancer033

I used to run MXs at about 34-36lbs and adjusted from there

95jersey

I have run MX's on the track and 32f 30r is a good starting point. Keep your eye on them throughout the day.

ghoffman

I am not sure what cold pressures are good for you, but I recommend that you focus on your hot pressures, per the tire manufactures' recommendations. Do a few laps, then have a friend get the pressures just off of the track. When you get the hot pressures correct, then measure them again when they cool off to ambient (cold) and write it down for future events. I think you will find that all 4 tires will have a different cold starting pressure to achieve the correct hot pressures. A pound or 2 is very hard to detect until you have considerable experience and most importantly, are consistent and smooth.

az55

This forum is the GREATEST.

Thanks for the help. I will probably run 32 all around and then check temps. The other car I used to run required 40front and 36rear because it was nose heavy and understeered. This car is well balanced,
(unlike it's driver)

I will get two sessions in Group3 before I do the Time Attack. I should be able to dial it in pretty close. This will be an enjoyable learning curve.

Cheers from Arizona.

WNeal

Not sure about running in the cold weather, got my first one coming up at VIR next week.

But,
Did several events last year on stock F1 tires and started out with 30, Tried 33 once and it felt less "safe" for some reason. went back to 30 for a while but then tried it again. Although it felt the same as the first time, I was faster with the higher pressure. Took a while to adjust to the feeling and get comfortable with it.

JMHO as I don't have nearly the experience as most of these guys but could definitely tell a difference.