I have a 96 SS and I'm considering getting 17x11 inch rims for the rear.
The ones I'm looking at have a 50mm offset. Will they fit???????

Thanx in advance

 

Just offering a little help. In the january 2002 issue of Chevy High Performance they claim the backspacing needs to be 7.75. They don't say but I assume this is inches cause it couldn't be mm. The 50mm ones your looking at only have 2 inches, sounds like they won't work. Call the guys at the Tire Rack to be sure.

 

I just bought 17x11s with the GS - 50mm offset. I believe they have something like 7.93" ~ 7 15/16" backspace. Becareful though and check out what you are shipped because I was sent 36mm offset (actual ZR1 vette wheels which have a backspace of something like 7 3/8") in 50mm boxes. Good thing I trial fit them (without mounting tires) because they really stuck out of the fenders. Some people like that look but I do not.

 

I stand corrected if you calculate a 50mm offset toward the front of the wheel this allows a 7.5" backspacing. You may have to do some mod to the lip inside of the wheel well depending on the tire. But these should work.

 

Thanx guys. I guess I forgot to mention that they are replica 50mm offset grand sport. does this change anything

 

It may change their weight. I'd suggest verifying the weights before you buy, just in case you're about to get some 35lb wheels in the mail...

Dave

 

Which replicas are they? The AFS replicas weigh 20.5 lbs for the 17x9.5" 56mm offset and 23 lbs for the 17x11" 50mm offset. This is for the painted versions, the polished may be ever so slightly lighter and the chrome will be heavier.

50mm is the offset you want for the 17x11"

 

here's a link from one of the mod's sites. great info for you

http://www.bfranker.badz28.com/96ss/11inchzr1.htm

 

The article on backspacing in the March 2003 issue of Chevy High Performance contains an error. They show how to measure backspace correctly - hub flange mounting face to the back edge of the rim, and they show a diagram of what backspace is, and the diagram is correct. But then they tell you backspace = 1/2 wheel width + offset, and that is where they go wrong. Backspace also includes the width of the flange that retains the tire bead. This is necessary, because wheel "width" is measured between the bead flanges, not the actual width of the rim.

In the case of the AFS 17x11 GS offset (50mm) replicas, the backspace is 7.93" which is made up of:

1/2 of wheel width = 11 / 2 = 5.50"

offset = 50mm / 25.4 = 1.97"

flange width = 0.46

Backspace = 5.50" + 1.97" + 0.46" = 7.93"

The AFS website confirms this backspace. And I just verified that measurement on my 17 x 11's, which are off the car.

The 50mm offset wheels, with a 315/35-17 tire on them, will fit completely inside the profile of the fender, when you look straight down from above. But, this MAY result in the tire rubbing on the inner fender liner, which can be hammered a bit to increase clearance. You will also find the jounce bumper bracket ends up "inside" the back of the wheel, which is not a problem at normal ride height, but will be a problem when you jack the car and let the axle go to full drop. Grinding the corner off the jounce bumper bracket cures this.

In an extreme case of body mis-alignment over the axle, it may need to be recentered with an adjustable panhard rod.

The 36.5mm offset wheels will move the outer edge of the tire another 1/2" toward the outside of the fender, and as a result it will stick out of the fender profile. Not the way to go, IMHO. Any further than this, and it is going to look "wrong":




17x11 w/ 50mm offset, 315/35 BFG DR's