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2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
Originally Posted by Street89vette
Trying to maximize inward offset to push 12" tires under fender wells. OK to stick out some. Will 12" rub inside at 40mm ?
Sounds like you'd get some rubbing when lowered but, at stock height (like mine), it's perfectly fine with 36mm offset rears. (Either sits beyond the fender line)
So you're clear, stock wheels are 56mm NEGATIVE offset. 40mm wheels will move 16mm outward -- not inward. 56mm offset sits under the well with 315's on GS models. And, the body is the same as the base cars.
Note: To be even MORE clear, if you're talking 40mm positive offset, that summabeach would stick out of the wheel well about 3". A 40mm negative offset (12") wheel is gonna stick out at least 1.5" Maybe a bit more if you're mounting 335s.
Sounds like you'd get some rubbing when lowered but, at stock height (like mine), it's perfectly fine with 36mm offset rears. (Either sits beyond the fender line)
So you're clear, stock wheels are 56mm NEGATIVE offset. 40mm wheels will move 16mm outward -- not inward. 56mm offset sits under the well with 315's on GS models. And, the body is the same as the base cars.
Note: To be even MORE clear, if you're talking 40mm positive offset, that summabeach would stick out of the wheel well about 3". A 40mm negative offset (12") wheel is gonna stick out at least 1.5" Maybe a bit more if you're mounting 335s.
There's a good bit going on there in that statement that's likely 'incorrect'!
40mm offset on a 12" nominal rim width would give you 8.07" of backspacing. I generally found that 7.96" was about the max without contacting the inside in places with my various 11" rims and 315 tires. I think if you ran 335s on 12s with 40mm offset, you'd probably get some rubbing. You might - might - get away with it using 315 tires. The tire width and diameter both matter here: the more of either dimension, the more likely you are to get rubbing. At 40mm offset, you will get a little poke out of the fender edges. 37mm offset on a 12 would give you the same 7.96" backspacing that works well with 11" wheels and 315 tires, but it will poke even a bit more. Your best bet may be to spec 40mm offset, but be prepared to run 3mm (or up to 5mm) spacers to fix any rubbing. That's fine to do, but you may need slightly longer wheel studs to run the spacers safely (depends on how much thread you can capture with the lug nuts).
Originally Posted by GREGGPENN
So you're clear, stock wheels are 56mm NEGATIVE offset. 40mm wheels will move 16mm outward -- not inward. 56mm offset sits under the well with 315's on GS models. And, the body is the same as the base cars.
Note: To be even MORE clear, if you're talking 40mm positive offset, that summabeach would stick out of the wheel well about 3". A 40mm negative offset (12") wheel is gonna stick out at least 1.5" Maybe a bit more if you're mounting 335s.
Sorry be pedantic here, but you have this backwards. Moving a wheel toward the inside of the car is positive offset, and pushing it to the outside is negative offset. This just semantics, but it will get confusing fast if we don't standardize the terminology. You might have been mixing this up with negative camber, where the top of the wheel moves toward the inside?
Also, the 17x11 rear wheel on the 1996 GS had an offset of 50mm, not 56mm (the 17x9.5 fronts and rears on C4s had 56mm offset, though). They do fit perfectly on the front or rear of any 88-96 C4, though, and that's why my car had 50mm offset for all three of my 11" wheel sets. I still don't know why Yak experiences rub with his set. My car was lower than his and still didn't do that. I believe him - I just don't have a good explanation.
thanks, should have ask what is the maximum positive offset for a 12" wheel with 335 tires.
No worries there. Nobody ever says "positive offset." It's just offset, and it's understood that you mean positive offset, because that's almost all that's ever used on cars. If you want to talk about negative offset, then you need to add the adjective.
