DougsfastZ

iTrader: (4)

I just bought a set of used chrome ZR1's. They were sold to me as "17" x 9.5" (+56mm offset with 7.4" backspacing) 17" x 11" (+50mm offset/7.93" backspacing)"

I just put them on the car and found two issues. One, the rears seem to stick out more then I thought. I was ready to pound the wheel well to make them fit, but there is plenty of room back there. Are these 38mm offset wheels?

http://www.zmydust.com/dougsfastz/im...1's/Rears/

Also, it looks as if I have two different offsets in the front. I thought the 9.5's only came with 56mm offsets? The front passenger is perfect, tucks nicely, but the front driver sticks out like the rears. I tried to take picutres of the difference of how far the spokes come out from the brake caliper between the two wheels.

http://www.zmydust.com/dougsfastz/im...t%20Passenger/

http://www.zmydust.com/dougsfastz/im...ront%20Driver/

Anyone have an idea as too what these offsets are? Any way for me to check?

Thanks,

Doug D

ls2 bait

iTrader: (11)

looks like u got sold some mismatched wheels. if i had to guess on the fronts id say one is a 9 (slp style) and one is a 9.5 (any other aftermarket style) if u also look at the lugs the ones on the drivers front looks like the lugs go in the wheel more so than the pass side. the rears look like a toss up. pass doesnt look bad but drivers side sticks out. rears prob not centered correctly. there should be less than 1/2 inch between ur wells and the tires on the rears if they are the 50 mm. mine come incredibly close and on a real hard turn (45+ mph) they will rub a bit on the inside.

JGKadell

iTrader: (4)

my wheels have the sizes cast into the back of the spokes. Looks there.
http://i30.photobucket.com/albums/c3...6/DSC00677.jpg
http://i30.photobucket.com/albums/c3...6/DSC00679.jpg

99ssleeper

iTrader: (98)

The drivers front wheel appears to be a 38mm offset. GM/SLP wheels have a 50mm offset and some aftermarkets have a 56mm offset (tuck in 1/4" too far). That one looks like it sticks out too far.

The passenger front looks like it is a 56mm offset wheel since it tucks under a little.

The rear ones appear to be the 38mm offset since they are slightly outside the fenderwells.

I've dona a lot of research on the ZR1s so hopefully this helps. As JGK says, check the inside of the spokes, there may be something like 17/9/56...meaning 17x9 56mm offset...

TXAgZ28

iTrader: (1)

If you want to verify the backspacing, measure the distance from the mounting surface to the inner edge of the lip of the wheel. Check out the attached pic for reference.

Those rears look like 38's...

JGKadell

iTrader: (4)

take a look at my pics.
I have 17x11 on the rear with 50mm and the fronts are 17x9.5 with a 56mm
http://photobucket.com/albums/c305/JK1066/ZR1%20wheels/

I am pretty sure the GM wheels only came in 17x9, and not 9.5 on the f-body. Now for the c4's I think they made a 9.5 GM wheel