I've done a lil bit of searching and can't find a concrete answer. I've seen 18x8 asteroids on some cars, but can you go just a lil' bit wider. looking at some rims with these specs:

wheel size 18x9
bolt pattern 5x4.75
offset +24mm
backspacing 6"

Is it do-able and still be kept within the wheel wells? I don't mind doing a lil messaging to make it work(trim here/rubber mallet there/grind this sort of thing). They will have to have the centers bored. Any help would be appreciated and sorry if this well beaten dead horse subject. Thanks.

 

Wider wheel needs wider tire. If you got the offset skewed for a wider wheel and trimmed the bump stop mount you can run a 9 inch rim. The tire is another matter. The widest I was able to run with a 8 inch wheel was a 235 on a 17 diameter wheel...and I had to trim the fender lip back a 1/4 of an inch. Good luck!

 

icsamerica,

Do you remember what offset/back-spacing that was?

 

I cant answer your question because those are the the wheels I ran before I flared the fenders. I'm now running 9.5 in wheels with 6.5 in offset. This setup puts the inner side of the rim and tire extremely close the inner wheel wheel and I had to remove the bump stop for clearance. A quick calculation suggests the 8 inch wheel will need a 5.75 inch back spacing. This is a common wheel offset for the 3rd gen Camaro and thats the application I'm using for my wheels so I can get them off the shelf and not custom. Custom wheels are very expensive and choices are limited these days. If you dont want to trim your fenders lips you can get a wheel with a more custom offset like an 8.5 inch wheel with a 38mm offset. I chose not to go the custom route because I wanted to use off the shelf parts so I could send them back if they rubbed. Dynamic testing shows as the wheel travels up and down in on the suspension it tucks in quite a bit. So are rest and level the wheel may not rub but when the suspension compresses it may. If it does with with a custom wheel you're stuck or have to add a non ideal spacer.

Additionally I also wanted to use near stock offsets so thrust angle and front suspension geometry remain as designed. This way the handling characteristics would remain the same as designed and lead to neutral and predictable handling characteristics.

 

If you can source a rim that is close to what you think might work, it will help, by fitting it and taking measurements to see where the extra space is, and calculating the offsets from that, it will make the process a lot easier.

 

If I can make it happen in time. Wheels are a close-out and not being reproduced. The easy sizes (17x7/17x8/18x8) are basically none existing. I'll try taking a wheel off and do some measuring.

 

I think I have my answer. 17x8 with a 235 or 245/5017. Fronts need to spaced out for center caps and steering arm clearance. Rear needs to have bump stop trimmed as mentioned before by others.