I'm trying to improve the look and the stance of my 11' GT's tires without dropping alot of cash on a new set of rims.
What kind of wheel spacers would work well with my stock 18in rims?

 

Americanmuscle should have what you are looking for on the cheap.

 

I was thinking about the same thing but have a slightly different question -- is there a rule of thumb or guideline on how much spacer to use?

Or do you just eyeball the amount you want to shift the tires outward to fill the wheel well?

Is there any down-side to using spacers? (Other than the car getting dirtier because the tires will throw more stuff onto the side of the car now that they stick out more)

 

I have .25" in front and 1" in the rear. It depends on the car, but a general rule of thumb is anything over 0.5" you will want the bolt on spacers, under 0.5" you may get away with the slip on type. My rears bolt on to the hub like wheels...then they have new studs which the wheels mount to. Maximum Motorsports' spacers come with instructions on how to properly measure how much wheel stud you should have for the lugs to properly secure. They measure it by a certain amount of threads the lug should cover.

 

Wheels spacers will add areas of increased stress into the system. Depending on how far out you can create greater shearing forces on the studs and with a parting line (due to being a multiple piece system) you'll have localized stresses at that point.
People seem to use them without problems but they seem scarey to me. I'd like to hear from some road racers that use wheel spacers to see if they've experienced any issues? A road racer would probably be the most extreme environment for these cars that is why I'd be curious.
Maybe you could consider just going with wider tires and changing the profile to fill up the gaps? To me that sounds safer...so if you have a 255/40/18...maybe you could try a 275/45/18? I dunno, I havent given it too much thought...just an idea.

 

If you use hubcentric spacers this will not be an issue. The spacers will fit tight to the hub just like the wheels do, so there won't be any stress on the lugs. All quality spacers are hubcentric. Use cheap non-hubcentric (lugcentric) spacers and all bets are off. I've used spacers on Many cars....Porsche's, Audi's, Z cars, Ford Explorer's etc without any problems ever. As to race car usage, remember back to the early Porsche 930 Turbos.....That wide body look used really wide spacers to adapt the Stock chassis and wheels to the body. Lots of race history there!

A bolt on style Hubcentric spacer will look like this. Note the center which is sized to mate with the wheel perfectly, just like the spacer has a recess to mate to the hub. If you are using aftermarket wheels you may need "Hubrings" which adapt the new wheel to the OEM hub diameter.

 

I personally won't use anything over 1/4" spacers without going with longer studs. I've used spacers from H&R and Maximum Motorsports and both have been very high quality IMHO.

 

Definitely...If you're using the Sandwich style, you'll definitely need longer lugs...