Gun

I new to the rim/tire world an d had a couple of questions. On my soon to have FD I plan on going single turbo hopefully having 400 RWHP so I was thinking that I would need to run wider tires to get more traction. I don't care about bigger like 19" rims but was looking at 17" rims but had no clue about width. So what is the widest rim you can use on a FD? Also if you have a 17" x 9" rim how wide would your mounted tires be? 9"? 10"? Help please.
Secondly I was looking at running the same size on all four corners. Is this the best set up for a street car? I don't think that when I get my FD that it will see the track or the strip.

Help me out so I can learn or at least point me in the right direction.

thanks Gun

SleepR1

READ ALL FOUR PAGES

https://www.rx7club.com/forum/showth...threadid=41789

SleepR1

With the stock-style springs and shocks, the widest possible tires and wheels to run at all four corners is 255/40-17 on 9 x 17, with offsets between 45 and 51 mm. 255-mm section width is roughly 10 inches. Usually this is a bit conservative, as most 255s mounted on a 9-inch wide rims measure ~10.25 inches wide from sidewall-to-sidewall. They're similar in overall height to the stock 225/50-16 tire, which is ~24.9 inches. The 255/40-17 will range from 25 to 25.2 inches in overall diameter. Acceration loss due to gearing will not be an issue with 255/40-17s.

If you switch your suspension to 2.5-inch springs and ride height adjustable shocks, you can run 275/40-17s on 10 x 17 rims with 51 mm offset, 7.5-inch back space for the front positions. The rear positions wheels would have the same 51 mm offset, but would require 7.375 inches of back space to help the inside of the wheel rim clear the stock trailing arms. If you went with M2 trailing arms, you could stay with 7.5-inch backspace wheels all around, and be able to rotate tires at all four corners. You would need to raise or lower the car depending on tire shoulder-fender lip clearance up front, due to the 275/40-17s being taller than the stock tires by ~1 inch (24.9 inches overall diameter for stock 225/50-17 and 25.7 inches for the 275/40-17s).

The 275/40-17s will hinder acceleration due to the taller 275/40-17 tires and heavier wheel/tire combo compared with a 255/40-17 tire on a 9 x 17 wheel. The taller tires trade acceleration for higher top end speed.

SleepR1

This question has been asked and discussed for 6 pages. See Best Wheel Tire Combo thread. It has a sticky on it.