As the new autocross season begins I am looking for a better tire selection than what I can get with the stock 16 inch wheels, I am currently running 245s but want wider, at least in the rear. I am running stock 1987 Trans Am GTA suspension. What Wheel and tire sizes would you all recommend the information on this subject seems to be hit or miss, What is the widest wheel & tire combo possible without excessive rubbing on a stock 1987 GTA?

 

Great idea for an upgrade, tires have a huge impact on your handling. To answer your question, the widest wheel and tire combo you can fit on your car is an 18x11" wheel with 315/35R18 tires at all 4 corners. To make this work, you need to tweak a few things, namely rolling your front fenders and doing a bit of trimming on the battery box. In the rear, you need to use a big hammer on the inner fenders to give a bit more clearance. Not hard work, but not a direct bolt on either. However, with your stock suspension, I would not suggest going with this setup as it will be overkill for you. It's also expensive!

What I would consider is going with a 17x9" wheel which will open up a ton of high performance tire options for you in the 275/40/17 size. These wheels will be a direct bolt on without any modifications and be a big jump in performance for you. Hawks has a bunch of options here. I would do this first, then focus on making suspension tweaks as you become a better driver. At least for me, it took a long time before I was out driving a good 275 tire!

Hope that helps...