Posted by Sinewave on September 20, 1999 at 22:02:03:
I ran my 3rd autocross yesterday and it's becoming evident that I've reached the limits of the stock Goodyear GA's (205/65R15) on my '95 GLE. I want to remain in Street Touring class so any changes will have to be within these parameters:
max wheel width - 7"
max tire size - 225
min. treadwear rating - 160.
Also, the following tires are specifically NOT allowed:
BFG Comp T/A R-1
BFG gForce R-1
BFG Drag Radial
Hoosier Autocrosser
Hoosier R3S03
Hoosier Radial
Hoosier Dirt Tracker
Kumho V700
Yokohama A-008R
So here's what I'm thinking. Get a set of stock steel rims (7" wide, I think) and mount a set of USED Dunlop SP9000 Sports on them and change them at the track. I've been told that tires with very little tread left will perform better on a dry track.
I've been told by a guy at a tire store that 215's are the widest you can go. I would prefer to go with 225/50R15's if they will not rub. Wether 225, 215 or 205 I will still go with a 50 series tire. I know it will be a smaller dia. than stock and that it will throw off the speedo, but it's just for the track and I'll effectively get a gear reduction for quicker acceleration.
So here are my questions:
What is the width and weight of stock steel rims?
Should I buy alloy rims to reduce unsprung weight? If so, which ones?
What is the max width I can use in a 50 series 15" tire?
Any other tire recommendations (remember 160 rating min.)?
Will worn tires really stick better?
Any comments would be greatly appreciated.