Using wheel spacers to even up front and rear track
 

Hello,

So after talking with a wheel vendor about gettign some 18' wheels to put a set of r compounds on for track and autocross use they recommended a some 18X 9.5s with +20 offset all around. I was thinking of running 275s all around. Now i know wider wheels will fit but, I just drive the car for fun so I don't feel I need the wides wheels possible.

Other than being a little worried about clearance in the font i also concerned that I will end up changing the track with relationship front to rear (fronts pushed out more than the rears). Is it a bad idea to run a 10mm or 15mm spacer on the rears to even up the track or should I just buck up and get wheels with different offsets?

Many people on here have installed spacers, including myself.

For NASA time trial events, I'm going to run 275 square setup with identical wheels front and rear so i can swap... will be using 15mm spacers on rear... problem is going to be oversteer, so I will tweak my suspension setup to try and get it more neutral with this config

Alright so it doesn't sound like I'll be the only one using spacers to accommodate a square set wheels. Now I just have to convince myself that a 20mm offset isn't too pushed out in the front.

if you lower it it wont appear like a 4x4.

Travis, can I ask what offset you are using in the front?

18x10 +34 all around

See that is what worries me, you're running 34mm offset . I think the 18X9.5 20mm offset that the wheel vendor recommended is too aggressive especially with a 275 tire I'm trying to run and without camber arms. They assured me that they won't rub but I can't anyone running that kind of offset without a lot of negative camber.

I run about -3 front negative camber and have maybe a quarter inch of clearance without rolling the fenders... that's also with a 285 hoosier series tire on the front, which runs more like a 295... so, what's the math? according to this calculator
http://www.1010tires.com/WheelOffsetCalculator.asp
you'll be an extra 8mm out... which is about 0.3 inches... I suspect if you run a 265 or at most 275 tire with -1.0 camber, you'll be fine