I'm trying to figure out rims for my race tires for autocrossing next year. I want to widen my track as much as possible to improve stability.

The Box will be about 1" lowered on Swift Racing springs come spring, and I'll be running a 15x6.5 or 15x7 rim with 195/55 tires.

I'm wondering what offset is best. My primary concern is getting as wide a track without risking rubbing on hard cornering, Aesthetics of what looks good is irrelevant as these will be my racing-only wheels.

I'm asking because the last thing you want is a rubbing or torn tire when you're doing this or this.

 

if ur gonna run 15x6.5-7 u should b able 2 run whatever off set u like, when u get into tha 15x8's is when offset becomes a big deal

 

I think you can get as low as a +30 mm offset & not rub at all. You could probably even get away with a +25 offset if you're doing a 6.5 to 8" wheel.

 

6.5 to 7 wide rim shouldn't be an issue.
im on ajustable coilovers that ive got set up to be a little lower that the s-techs, ive got 16x8 +15 and no rubbin.
well..... my rear fenders are also rolled.

but your not going that low.
my front end is a little under 4" off the ground.
my front is lowerewde about 2.2-2.4, and the rear is 1.8-2.0

if your only going 1" and a 6.5 to 7 rim you should have no problem with any offset.

go with a 0 is you can find it

 

+38 offset or lower i believe would be what you'd want. i'd go a 205 for section width on the tire put down a little more contact patch for hooking up.

 

you could run et15 f/r and you'll be fine.

 

^ on an 8"

You should be fine running anything that you can find (that is a positive offset) on a 6.5/7 and not have issues. Most will be +35 or so.