I have H-sport springs with stock multi-piece wheels and 215/45/17 rubbers all the way around. I'm thinking about running 5mm spacers front and rear.

What are your thoughts on that? I wider really better? How wide can I go without rubbing issues?

 

wider is 'better' to a degree, but 5mm will probably make no difference
for street applications. (You really need to change at least 10mm to
really be able to tell a difference through your steering feedback).

depending on what offset you're currently running, you may run the
risk of rubbing the rear fender.

 

You can achieve the same thing going from 7" wheels to 7.5"

 

actually that is not the same as running a 5mm spacer.

 

Wider track through spacers may be better, but it also changes your suspension in a sense. Going 10mm in the front may give you a bit better oversteer, but will start introducing more scrub. Wider in the rear may induce more understeer.

I think I would try and stay clear of anything more then 5mm in front and 3mm in the rear if spacers are needed to help tire clearance. I'm not sure I would do it looking for any performance gains.

 

Correct! The additional 1/2" can be biased to the inside of the wheel's centerline preserving the original offset, or not. A spacer will change offset.

My everyday BBS wheels are 38mm offset and the track wheels are 45mm offset. The tires are different, so I cannot offer any advise.

...this just made me think of a problem...hmm... Onasled, what offset are your wheels?

 

"Was" using a 17x7.5 with a 45 offset, but I was using a 5mm front spacer and a 3mm rear, so that obviously changes the offest that much.

So, without the spacers, that gave me a backspace of about 5.75" (back of wheel hub to inside rim. I might bet Meb that you are more like 5.25" there being you have 7" rim with a 45 offset. (I think...:impatient )

 

You must know that I'm air head by now...I've been performing setup work - by feel - with the 205/45/17 summer rubber on 38mm BBS wheels while running on the track with 205/40/17 on 45mm offset TD wheels...another reason to have a track only car.

Onasled, did you have an opportunity to perform back to back impressions with and without spacers? Okay well duh, that's sort of not possible unless you change out the studs at the track. See, told you I'm an air head.

 

My 'studs' can take both ways. I had to run the spacers only because of tire clearance. So I never ran with them off with the same tire. (235-40-17)


(Yikes, that sounde kinda bad... )