Positive Offset/ Backspacing

[2fine69]

Does anyone have max. backspacing measurement (positive offset measurement) on rear of 2SS? I know 305 is the max on factory wheel, but is there enough space behind wheel to add additional backspacing to the wheel to accomodate larger tire? My car is ordered, and I really want to order wheels before it gets here, If you have this info, please help!
I just have to believe theres gotta be some space left to fill!

[75rusty]

Pretty sure 305 is max width period, may want to search. The guys I've seen pictures of running 305's on stock wheels had them widened.

[Nine Ball]

The 2010 Camaro can easily fit an 11.0" wide rear wheel and a 315 tire. Custom forged wheels typically take between 5-10 weeks to build depending on brand, so plan accordingly. I'd be glad to assist when you are ready, the brands I carry are in my signature below.

Tony

[chevyss]

Does anyone know the back space on the stock wheels? I'm working to get a new set of wheels and the wheel company needs to know the stock BS. Thanks in advance

[2SSRS@Gen5diy]

Originally Posted by 2fine69

Does anyone have max. backspacing measurement (positive offset measurement) on rear of 2SS? I know 305 is the max on factory wheel, but is there enough space behind wheel to add additional backspacing to the wheel to accomodate larger tire? My car is ordered, and I really want to order wheels before it gets here, If you have this info, please help!
I just have to believe theirs gotta be some space left to fill!

Hope this helps you, This is from the Forge line Web site with the numbers off my car. http://www.forgeline.com/wheel_fitment.php

all for the rear.
Front spacing = 100 MM
Rear spacing = 235 MM
Caliper clearance =40 MM This you need to check (GM changed the brake pad)
Caliper height = 215 MM This you need to check (GM changed the brake pad)
Hub diameter = 67 MM
Hub height = 12 MM

[flht99b]

Resurrecting an old thread here. Does anyone know for sure if you take a stock SS 20x9 wheel and widen the inside of it 1" making it a 20x10, is there enough clearance in the inner fender well, suspension components, etc. to do this with a 305/35/20 P Zero mounted ?? How about if the car is lowered 1" with lowering springs ( no aftermarket coil overs ) ?? My measurements with stock springs/ride height look like there is plenty of clearance to do this. But I may go for 1" lowering springs in the future. It appears a 10" wide rim is sufficient for a 305/35/20 Pirelli P Zero as some folks have already mounted this tire on a 9" rim but I'll listen to the tire experts if I'm wrong. I do not want to run wheel spacers and I like the look of the stock Midnight Silver wheels.
TIA...Ed M.

[Nine Ball]

Ed,

Most widening companies prefer to go 2" or more on the hoop reweld process. Adding just another inch puts those two weld beads very close to each other. Most of the Camaro guys here simply put the 9" rear wheel up front and widen the front 8" wheel to 10" and put it on the back. Either way, spacers are needed to make them fit properly.

I hate spacers.

[nuptualnemesis]

I test fit an after market Z06 18X10.5 rear rim with a 8.04" back space and a +58 mm offset. It appeared if the tire was any wider than the rim the back would rub. It would probably rub in any event with squat on launch. The caliper also needed a 1/8 or 1/4' spacer not to rub on the front of the caliper. Some people say they run these without a spacer. Maybe a different brand would fit a little different.
The Z06 18x9.5 front rims have a 7.38" backspacing and +54mm offset which should provide enough back space but I don't know if a spacer would be necessary to clear the front of the calipers. http://speedwaymotors.com has the cheapest aluminum billet spacers.

Offset is from the outer part of the lug stud hole to the center of the rim either plus or minus. Positive offset moves the center of the rim toward the inside. More positive offset will move the back of the rim toward the inside of the car. (tire rub)

Backspace is distance from Inside of lug stud hole to rear of rim. Less back space less chance of rubbing inside of tire.

You also have to consider if a rim is center ecentric or lug centric. 2010 camaro has a centering ring on the inside of the rim that fits over the axle hub to center the wheel. The Z06 rim is also center ecentric and has a different size centering diameter/hub diameter. This centering is lost with a spacer, although a 1/8" spacer may be OK if the hub diameter is the same. Most people with spacers are using the bevel on the lug nut to center the rim.

I have 20x10 OZ rims with a +45mm offset and 7.28 back spacing that work great.