I'm autox-ing my 93 R1 - as stock as the day it left the dealer - and running Kumho Victoracer V700s. Usually I just air up to 40lbs F&R, and they seem fine, don't roll over the sidewalls, neutral handling. But without a heat gauge, I'm guessing. What is everyone else running as to pressures???

Don

 

They say to start at 40psi and adjust accordingly during the day. I have yet to run, first day this saturday, so I will let you know where I end up.

 

I have used Kumho's for years but I have never run an autox. for road racing my setup was to start around 29psi(depending on track temp) cold to try and achieve 35psi hot and 180*F tire temps. 40psi sounds high to me but if it works then it may be the hot setup. I might start at about 35psi and experiment a little bit.

 

for road racing at summit point.... LF 26 RF 27 LR 27 RR 28

the left front takes the most abuse. the idea is the have the tires at the perfect pressure when there hot. this takes some experimenting coming off the track and taking pressures immediately. but for running the street... mid 30's id say

 

i don't autocross, but for road racing i use 28ish cold and shoot for 35-36 hot. at 40 and above the v700 seems to have progressively poorer grip on my car and setup.

good luck
fabian

 

What size tires? It makes a difference between 16's, 17's, and 18's? On 245/45 16's, I usually start out with 34psi (F) and 30-31 psi (R). Depending on the surface and the ambient temp, I'll adjust accordingly.

 

yeah, excellent point. i neglected to mention my sizes are 285/30-18 all around.

fabian

 

all the info i gave is for 205 60 13

 

My tire sizes are stock: 225/60/16.

 

don't believe that's stock size....

225/50 or 245/45 should be the sizes you can go with.

 

Probably a typo. Kumho doesn't make a 225/60 16. At any rate, you should switch over to a 245/45 16 for the stock wheels. Much more grip available with the wider rubber. Trust me, you'll like it.

 

I agree with Red Rotor. I've been running on V700 Victoracers for the last couple years on my 94 is SS. I use 32-34 front and 28-30 rear. I have about 1.7 degrees of camber in the front, and about 1.1 in the rear. If you have less than that, you should bump up the pressures by a pound or two.
245/45-16 are definitly the way to go!

 

It was a typo, I do have 225/50/16s. The guy at Tire Rack told me the 245s wouldn't fit under the fender, they'd rub under hard steering. Not true??

 

No, not true. Fits perfectly. I have plenty of clearance even with my hellacious body roll and nose dive. (I need stiffer springs)

 

The 245/45/16s fit both front and rear, or just on the rear?

 

I run 245/45/16's at 38 - 40 in the front and 34-36 in the rear. I also have adjustable KONI's all 'round. Seems like the perfect balance for me, no over/understeer and V700's have virtually no rollover.

Tomas
'94 RX-7 TT SS #142

 

I ran 35's front and 34 in the rear. It warmed up a good bit throughout the day but they stayed with me all day. I could probably lower it just a little more all around as I was not even close to wearing up the sidewall.

 

Race tires generally have very stiff sidewalls, so I wouldn't worry too much about rolling over on the sidewalls. As low as pressures I've set the tires to, I've yet to see any signs of sidewall wear-and-tear.