What is the biggest tire I can fit on the front and rear of a 1991 RX-7 Coupe using 15" and 16" using 7JJ rims? I want to AutoCross. Do you reccomend the use of spacers? If so what size? 25m/m or 50m/m? Would this be for front and rear or one size for fronts and another size spacer for the rears?
Thank you for your kind help in this matter.
Robert

 

I believe the biggest recommended size for a 7inch rim is a 225, but you need to checkout the Suspension/wheels/Tires/Brakes section for further information. Good Luck with the 7!

 

No larger than 225 on a 7'' rim. When you start going over the maximum size you will get sloppy handling because the side walls are pooched out part the lip of the rim and it lets it move side to side alot. id say 215 though would be ideal for 7'' wheels but some have gone larger, depends on the tire, some are different than others

 

get some rotas thatd be hot

 

Spacers aren't reccomended unless it's the only option left. If possible just get wheels that fit right from the start and spacers won't be needed. The size required would depend on wheel offset.

For autocross I'd get some 15x8's if at all possible and run some 225/45/15's for the best gearing and lowest height possible on 225's. I've only seen one 15x8 that'd fit our cars that's not terribly expensive, but it's a custom order item and they only make them when there's several people (5?) wanting them at once. I'll be trying to get a set early next year. They will require a small spacer, in the order of 10mm.

http://www.18racing.com/wheel_slipstream.html