Tommy T-Bone

I know this just came up in another thread but I didn't want to cut in on the other posters action. My thinking was was that higher pressure would give you firmer sidewalls hence better handling on the corners. Such as tires not folding under on high speed turns. I'm running on Firestone Firehawk wide ovals and I realize I'm at the upper end of the spectrum on tire pressue. Should I lower it to 35 when I'm running an auto-X as well as on the street? Or even 32 psi? Always looking to learn. Thanks for the advice.

AORoads

Go to Autocross Racing section of CF and ask same question. Should be interesting answers.

Vettin08

You'd think that was the case, but at that pressure, you're ballooning the tread and not even riding on the full contact patch. So while you may in fact gain side wall stiffness (I don't know), you lose traction/handling.

eschoendorff

DarkBlue88

What are your tire sizes and rim widths?

Redeasysport

As I said in the previous thread I work for GM mounting tires and the specs for passenger cars are 35psi + or - 3psi.40psi is not excessive but will affect tire wear.Higher than that is asking for trouble.Better to try 38 psi if you must.

ghlkal

I saw the post where he was running at 44psi (max allowed per the sidewall) and I wondered the same thing. I usually run ~ 35psi because running at the max scares me but, I don't really have anything to base that on, so I'm willing to hear what the experts say

Gary

Tommy T-Bone

I've got (4) P275/40R17 98W on stock 90 Corvette wheels. From what I've read so far I'm planning on dropping to 32 psi pronto. Unless I hear something different. Went and cross referenced Auto-X forum as suggested by LT4Compyell. Lots of good info on beginners sticky.Also explained a little about the tire pressure. Beginners t.p. + 6 lbs. That's where I got the 40psi from. Adjust with experience.

CMYC4GO

I run 40PSI in my tires, and I have had no significant wear problems. The car handles very well at high speed,on curvy roads.

Redeasysport

Just curious how many miles do you get on a set at 40psi?

Vettin08

Would handle better w/ less, but glad you're happy with it. How many miles on your tires?

Vettin08

I used to run at max pressure too when I was a kid. Just didn't know any better for a couple of years. Let that be a lesson to you divorced dad's out there, be a dad and teach your kids car stuff when they're old enough

Mine didn't

Cozmo

I went to an autocross driving school conducted by the local NCCC driving king (not sure of his actual title). He recommends 40 psi for agility during autocross.

C4driver99

35 psi should be significant. Over filling them causes premature treadwear and lose of traction. Bigger tires with more air pressure would seem to be a obvious soloution to traction but yet only a patch of each tire is on the ground as large as our palms(average size). So id advise to keep your tread up tire pressure at 35 and get good suspension to have better handling. Also a camberbrace/crossbar and other accessories have quite dramatic effects on the cars frame. Our C4s are flimsy in the bodys so it always helps to tighten it up and our stock shox are horriable compared to the gas ones used today. If im wrong someone please correct me

Vettin08

But wouldn't that be just for the quick turn in and not alot of sustained high speed corners? He said 40psi for autocross only right? Not all the time I hope.

C4driver99

with vader86

GGTOOLS

OK I'm no expert but I was always of the understanding that the MAX psi on the sidewall was just that max psi not to be exceeded. Like when tring to set the bead. I just always went by the placard. I think
tire psi. is some what subjective to conditions and prefercene. say +-3

Cozmo

Yup,
40 psi for autocross. For normal driving, I inflate my tires to 32 to 35 psi.

If you are going to the drag strip, deflate the rears for better traction and inflate the fronts for less rolling resistance on take off.

CentralCoaster

Miata tires and vette tires are like apples and oranges. Would this be different for wider tires? I see the contact patch being more sensitive to pressure on wider tires.

C4driver99

the vettes with the wider tires have a larger impact point. Making them more suceptiable to traction differences. Just follow the guidelines and it should work out.