John Lankes

Does anybody have offset recommendations for an 18x11" front wheel for the track? Car is a C6 Grand Sport, so I've worked out that the stock front rim is a 18x9.5" +40mm offset, which gives me 6.82" of backspace.

Going to an 11" wide rim, I'm thinking something between +39 to +46 mm, but I'm really not sure what hits first when going wider, so I don't know if I should bias more to the inside or outside. With the +39, I'm looking at an addition .71" or backspace, and .78" or outer face growth. with the +46, there is an additional .98" of backspace and .51" of outer face growth.

Right now I'm leaning towards splitting the two and getting +43, so that I can use a wheel spacer to push the wheel outward for clearance if I need to.

morris

I would touch base with the wheel manufacturer, they would know best I would think, plus if it is wrong you have some recourse

John Lankes

I ended up going with 18x11 +39, which is what Forgestar recommended so I'll figure out how they fit in a couple weeks.

froggy47

John Lankes

Just took the thing for a test drive and everything fits and clears pretty good. Front tires are a Pirelli 305/645-18 and rears are a 315/675-18. No issue with ABS / TC from rollouts, and no noticeable rubbing.