I have a 93 FD R1 that I use for street and auto x. It currently has 18” ASA wheels with 235/40-18 (front) and 275/35-18 (rear) Pirelli P Zero Nero tires. I am torn on which direction to go with the wheels and tires. I run in the street modified class with a gt35r single turbo. The car definitely has more power than grip. I have run a few events and feel that tires should be my first improvement, followed by suspension ( probably konis and springs). Should I get a second set of rims( maybe stock rims) and go with some sticky tires, or should I use the 18" rims and get better tires for them and then have some other set for street use?
I know the stock rims would be less expensive to source tires but will the larger rims benefit me for auto x?

 

I'll assume you haven't been autocrossing for years, and that means the nut behind the wheel is your best tuning opportunity. Find driving schools and test and tune events as much as possible. The second best is going to R comp tires.

Those 18s you have now are not much wider than stock. They are also massively staggered. Are you seeing big understeer? In any case I would tend toward keeping them as street tire wheels.

Stock rims with R-compounds will be an improvement. Stock wheels are very light and 245/45/16 tires are not a big handicap unless you're really trying to win your class. I think lots of driving work and this setup will get you much closer to the class leaders. No matter what tire/wheel you have you'll need to use your right foot well to go fast.

If your budget allows then a lightweight 17x9 or 17x9.5 with R-compounds (Hoosier A6's or Kumho V710s) will be ideal.

As for the subtleties of which size (17s vs. 18s) and how to stuff max tire on each corner, I'll let the vets who compete in SSM speak to that.

David

 

Yes, the driver "mod" will be my biggest improvement. The car does push through the corners to the point that I know it should be faster even at my limited driving skills.