I realize backspace for rear tires is a really hot-topic subject, but you never see people discussing front backspacing. If the stock front rim on my GTA is 15 x 8, and I reduce it to a 15 x 7, would i be required to reduce/increase the backspacing of the tire? Should I run a 4.5" or 5.5" backspace? Thanks!

 

teh stock rim on a gta would be a 16x8, if its a 15, its a 15x7, unless its a aftermarket wheel.

a 16x8 on the front wants to have about 4.5" of BS, which is the stock size, you can go a little deeper, no more than 5 or you will get into the tie rod.

15x7, would work with 3.5-4.5 depending on where you want the tire. 3.5 being just in from the fender lip, to 4.5 being an inch further in, and anywhere in between accordingly spaced.

 

16x8** that was a typo, planning on reducing to a 1#x7, I'll probably end up running a 17x7 with a 3.5 backspace then, thanks for the info.

 

Why go to a narrower wheel? Unless it is a drag racing only car, stay the same width (at least) or go wider & help increase cornering traction.

I have 17" x 9"/5"bs with 275/40sZR17s up front.

 

i have to agree, why not just bump up to a 17x8?

 

The car is being built up towards a street/strip drag car including a big block so I am not too concerned about handling, smaller tire is less drag/resistance/weight is it not?

 

Correct and why I asked the drag racing question. For drag racing,wider is not better up front, but for dual purpose, you wouldn't want 3" wide wheels & cookie cutter tires up front either, so yeah. 7" is a decent rolling resistance compromise between street & strip.

 

The larger diameter will put the rotating mass back to what it would be stock if not more. Ideally you should go with a smaller diameter along with the less width.