A guy wants to trader me a set of 17x12 zr1's for the rear and 17x10 for the front.... He said they came off a 92 zr1, but I don't even know what that is.... I want to put them on my 99 camaro, which is lowered with the prokit... https://ls1tech.com/forums/western-members/511065-black-z06-wheels-sale.html is the link to the thread, so someone please help me before I end up with something that doesn't fit....

 

Read this thread then get yourself a ruler and go measure
https://ls1tech.com/forums/wheels-tires/346147-wheel-sizing-chart.html

 

if i understand it correctly, the offset is guaged by the centerline of the wheel. if you have a 0 off set that should mean that the mating surface of the wheel (up and down)is dead center on the width (side to side) of the wheel itself. on a ten inch wheel this would mean a 5 inch back space. i believe if you have a positive offset the wheels will be a shallower dish and if you have a negative offset you will have a deeper dish. so with a 40 mm offset on a ten inch wheel i believe you would have a 6 5/8 inch back space. (10 inch wide 5inches on center so 5inches plus 40 mm which is close to 1 5/8 inches.) back space is the distance from the rear lips of the wheel( engine side of the wheel) to the mating surface of the wheel. get a straight edge and lay it across the wheel so that it crosses the center. measure out from the mating surface to the straight edge and you have the back space of the wheel. so if you have a ten inch wheel with negative 40 mm offset you would have about 3 3/8 back spacing which would mean you had a pretty deep dish.

 

I would measure and that, but i don't have the rims, maybe i could have him do it... but then i how would i know if they would fit on my car?

 

you could have him measure and then you could make yourself a cardboard cut out using the dimensions he gives you and put it up under there. i would think a ten inch wheel up front might be tricky but that is the only way i know off hand with out getting a buddy who works at a tire stor to put a similar wheel on for you to try.

 

UH, they should be 17x11 and 17x9.5, I dont recall there ever being 12 inch or 10 inch zr1's. But I may be wrong.

Either way, the rears should be 17x11 with 50mm offset, and the fronts should be 17x95 with 56mm offset. I can guarantee that you being lowered with the prokit will require a BFH to the inner fender wells, and you will probably have to rent a fender lip roller. Other than that you should be fine.

Fry

 

T = total measured rim width (measured from outside lip to outside lip)
B = backspace (measured from back of rim mounting pad to the outside lip of back of rim. Place straight edge over back of rim and measure the perpendicular distance from the mounting pad to the straight edge)

rim offset = B - (T/2)

for example:
if you have a total measured rim width of 10.5" (266.7mm) and a measured backspace of 7" (177.8mm), then you will have an offset of approximately +44.45mm

rim offset = 177.8 - (266.7/2) = +44.45mm

note: 1" = 25.4mm

 

I agree with Frey51. The ZR1 corvettes came with a 17x9.5 front and 17x11 rear. Hence, the replica ZR1 wheels are made in those sizes.

 

Well you know how some guys measure things

 

yeh i thought it was a little weird for someone to have 17x12's but then i figured he must know what he's talking about since they are his rims.... but thank you guys for all your input.....