86 IROC

I just yanked some thrust II wheels off my car.

This had pretty darn good fitment

Front:
17x8, 255/40/17 1.25" spacer. ET8

Rear:
17x9.5. 275/40/17 2" spacer. ET46

I am trying to avoid spacers, but so far not finding that possible, unless I'm willing to pay $600+ a wheel and I'm not

I bought some 18x10 ET20 with the idea that I could add 10-15mm of spacers with my updated studs and be okay..

Rear seems to be okay with 15mm of spacing (enough clearance inside and outside, sits a bit inside the fender I think I can manage this with custom spacers (the hub is different size than the front). Gen V1 rear brakes (9 Bolt)

Front I have updated spindles and Gen V1 Camaro brakes. Because our hub is so long (even though my setup is roughly 1/2" shorter than stock), these aftermarket wheels have a real strange idea of hub bore!!! So the fronts, I'd have to run a spacer just because I have to get beyond the hub and bearing end cap. That pushes the wheels outside the fenders (not good).

So what are the options. Did I make a mistake with thinking that a lower ET was the way to go to minimize the required spacer, or was my mis step the fact that our hubs are so long that you have to find a wheel that has a center section (like the American racing series), or is one just forced to run spacers?

@paul_huryk You seem to have been around a bit and know wheels and fitments, I've read a ton of your posts but I've been looking into this for so long, I think I'm starting to get wheel block I'm looking for someone to slap me around a bit and get me squared away..

Thanks!

 

In theory with an 18" x 10" wheel you would need a BS of 5.75" or offset of 6mm to fit flush with the fenders. But any sort of changes to the hub position or rear end width will alter this baseline.

What exactly does your car have to change the baseline offsets front and rear.

 

Thanks Paul

The rear 9 bolt is probably fairly stock in measurement, even with the added Backing plates for the Emergency brakes for the Gen V1 brake rotors. But i'm guessing this is very minimal of a change. (other than the large calipers and larger/thicker rotors(does have new longer studs).

Front different spindle, which changes the hub size a bit as well as push the hub a bit more out..So in theory I should have a bit more backspace available in the front.

The BS of these wheels should be in the 6.37 neighborhood, and as I stated with roughly 15mm of spacers they will fit in the back, but since I have the large hub length in the front, requires too much spacer to fit right. So the ET22 front can't overcome that, which tells me I need something in the 0-5mm, but regardless it's going to need an 1" of spacer to fit the hub. (I believe). I only have 2 wheel sets here that I cam reference with on this vehicle.

Tory

Fronts there really is no chance in heck based on the hub size. I understand ET/Backspacing but neither means anything if the wheel doesn't provide enough access for the super long hub bearing/cover.

Based on various checks, if our hubs were not so long, this fitment would work, but since I have to space the wheel out to handle the large hub length, it throws things off.