How much do you think I can widen the wheel inside without hitting? 11"? What is the formula to correctly keep side wall ratio to stock? I want to go about 305 or 315 and keep the profile I have now.

 

I'm not sure about the limits that you can safely widen the wheels before you start hitting suspension, etc, but this site may help with determining tire sizes.

http://www.rimsntires.com/specs.jsp

 

What factory wheels do you have? You can always run a spacer to push the wheel out. I would anyways, even if I didn't widen them. The offset tucks them in so much....

 

I want more meat on the metal.

Holy crap!!!! That link is exactly what I've been looking for!

 

I don't think you can fit 11" wide wheels under there.
Those would be huge and weigh a ton anyway.
Look into 9.5 or 10" wide wheels
Too keep the same overall diameter as the OEM brembo tires you need
285/35/19 tires (same size as the GT500 wears)

If you want to go wider you'll need to drop the sidewall height down and then the ride gets awfully rough.

 

I going to put 15mm. spacers on my factory 19s when I have it lowered. I was told 1" was too much and didn't look good.

 

Check the dimensions of the Steeda Spyder wheels for offset info. This wheel is 20 x 11, and I believe they run a 305 series tire, so you can definitely do it.

 

Steeda rear 11" wide 315/35-20, tire and wheel 69.5lbs, +13.5lbs more than stock

The deal is you have to go 20" to get the wheel away fron the pumb stop support. A smaller wheel 11" wide will hit the inside with the offset that clears the fender. So I assume you don't want the wheels sticking out or the car jacked up. I have seen 10.5x18 wheels clear.

 

Thought so, thank you sir.

 

I'm sorry to be dense.... NO REALLY! Are you talking about having someone take your factory Brembo Wheels and have them make them wider??? Sounds great to me, I love the look of the Brembo Package Wheels, but would love more rubber in the back. Keep us posted. SORRY if I completely misunderstood.

 

I've been pondering widening my rear tires and having them powdercoated blk but just buying new wheels in the exact size and color I want seems easier. Keep us updated...