I ran my RA1s at ~36 hot.

 

Hi Pete,

It wouldn

 

Too much. 31-34 hot is what you want. Pump them up for the freeway then drop them to about 28 at the track. That should get you close. Street tires need to run 39-44 hot, DOT-R 30-37, slicks much less than that. There are arrows on the shoulder. You should have enough pressure to wear the tire to the tips of those arrows, no more, no less.

 

Josh Goldberg and I did some testing of hot pressures on the skid pad at Buttonwillow. We experiemented with various pressure values for high 30s down and also with front to rear differentials. We basically did the same tests at the same time with different cars but both on RA1s of about the same wear and came the same overall conclusion.

We had the fastest speeds and best balance with 31 rear, 33 front. Since then that's what I've always run and have had the tires wear dead even, even front to rear.

 

As a noobie, I thank you!

 

[QUOTE]Originally posted by cthree

 

Yeah 42 is just about the grease barrier with the RA1's. I usually run at 38lbs hot front/rear/left/right and then tweak for the cars behavior throughout the day.

 

I ran my current set at about 31-32 hot on their 4th track day, and they actually started "going away" mid-session! I knew I must be doing something wrong, since a) they had a lot of rubber left, and b) RA1s *never* go away! Since then I've had much better luck with 35-36 hot, and I may even experiment with a little more.

Note that I'm on stock rims; I think the optimum pressure will always depend on the tire size and profile, and the car setup.

 

Yep, setup has a lot to do with it. All the RA-1 info I've seen that recommends the high pressure also wants a ton of camber, i.e., 2.5 to 5 degrees which is more than we can achieve in front with stock A-arms; the rears can just about get in to the desired range.

Not sure how that relates to pressures but I'm sure it's all connected.

 

[QUOTE]Originally posted by Ludedude
Yep, setup has a lot to do with it.