LouieM

I run the occasional autoX in my stock 67 roadster with 215-65-15 tires. The Yokohama AVS tires (V rated) I just took off looked a bit "melted" along the mounting lip where the tire meets the rim; these tires still had some tread, but had some internal problem, since they tended to pull the car left.

I just put on some Yokohama Avid H4 (H rated) tires and want to avoid "melting" these. In the past I've set the air pressure at 38 pounds for an autoX or track day. I assume that this was too low, and that the tires squirmed on the stock steel 15X6 rims and deformed.

What is a recommended pressure for these tires? I'd like to find out before I run the Marina CA autoX this Sunday.

Gordy M

Its been since 1984 that I ran those size tires on a midyear. I believe they were Eagle GT's. Anyway, I ran 45 lb front and 40 lb rear with the F40 suspension and stock alighment. I am not sure if todays tires have stiffer sidewalls but I am sure they have better compounds. Any kind of tire pyrometer would also help.

LouieM

Thanks for the info. I'm stuck with these "motorcycle tires" because they are the largest that will fit FOR SURE without possibly trashing the fenders. My 67 has the base suspension, but with Bilstein HD shocks, so I'll go with your 45/40 unless someone else mentions a better set of pressures for this suspension. One day I'll have a pyrometer, but not yet. Thanks again!

Gordy M

You can also get 225/50x15's on without harm, but it takes a 3.70 gear and makes it a 4.56

LouieM

I ended up using 40 front and 40 rear, because the little air pump I used wouldn't go up to 45 for the fronts. The car understeered a bunch, which slowed me down a bunch, but the handling was very predictable. Time for a new air pump!

GordyM
I already have a 5-speed tranny in that makes my stock 3:36 act like a 4:36 in first gear, so I definitely don't need to go to those tires!

Louie