Why is there a different offset on the GTA wheels from front to back? I'm guessing it has something to do with fitment under the wheel wells. Maybe something else...

I have a screwy problem. I have Ed's LS1 brake kit on my car that currently requires me to run 1/8th inch spacer on the fronts to clear the calipers with the GTA rims. It's real tight in there and my left wheel rubs the wheel well in hard right turn (presumably due to the spacer). Anyway, I have bent rims and am shopping for new wheels. I want to stay with 16 inch wheels and I would like to be able to do a 4 wheels rotation with the tires.

How do I know what to order?

Is this correct:

• 5 inch back space, 5 X 4.75 bolt pattern. Zero offset.

Will that be enough information I need to order the new wheels??

And yes, I read the sticky.

 

The factory 16" wheels, GTA or otherwise, have different offsets so that they clear the "frame" at the front of the LCA mounts on the rear, and the sway bar and fenders at the outer rear corners in the front.

GTA wheels have a "feature" on their inside surface that is brake-hostile. Other factory 16" wheels, and most aftermarket wheels, are not this way.

5" BS is too much. Factory is about 4" on the rear and about 3½" on the front (8" wheels). At 5", you will have rubbing problems EVERYWHERE. 4" will work, at up to about 9½" on the rear and 9" on the front, without too much rubbing, if you can educate the driver(s) of the car to be careful about not turning the steering wheel all the way to the lock, and if your Panhard bar keeps the rear end well-centered (can be a problem if the car is lowered or the springs are worn out).

 

Thanks sofa!

My interpretation of what you said is that I can get a set of wheels with the same offset and back spacing on all four corners using these specs:

• 16X8 inch wheel
• 3-3.5 inch back spacing
• Zero offset
• 5X4.75 Bolt Pattern

Will that do it?

Sorry to be dense...

 

Aww, forget it.

I'm just going to get some 17" ROH ZS's with tires.

Merry Xmas to me!

 

Cadillac,
Whatever wheels you buy that's cool but you still need to understand the terminology. Offset and backspacing are used by different people to mean the same thing. Let's say you have an 8" GTA wheel 8 inches wide. Divided by two is 4 inches on either side of center, so that is 0 offset or 4 inch back space from inside wheel measurement. If you have 3 inch backspacing then your wheel will stick 5 inches to the outside. The front wheels on your GTA TA are 0 offset or 4 inch back space. The rear ones I believe are 1/2 inch offset to the inside or 3.5 inch back space. I think that the rear wheels where that way because the rear end was to wide and so not to rub on the outer wheel well they were tucked in.

Marty