I'm working on the C4 HD brake upgrade. I have 4th gen 50mm offset wheels 9" with 274/40/17 tires. I'm using 1LE hubs with the brakes. The hubs move the wheel out about .330". The C4 HD rotors move it out about .300" thats 16mm. If i were to go by the standard 2" spacers (51mm) i would get a 35mm spacer for the front and all should be well.

the question is:

If i were using stock brakes with a 2" spacer, and i lowered the car, would i have any issues with fender clearance? How much thinner could i go with the spacers (assuming stock brakes)??? I swear the 2" spacers normally make the wheels stick out a bit too far.

Lastly:

Will 1 3/4" spacers work in the back? with the wheels mentioned above? or will that cause issues too? I have 4th gen rear disks i'm hoping to retrofit will they move the wheel out anymore than stock disks?

 

When I installed my 17x9.5" z06 wheels up front with a brake upgrade and 1.7" adapters, fender clearance wasn't as much of a problem as wheel to tie rod clearance. With the 1.7" adapters, my wheel would come in contact with the outer tie rod (just barely), so I ended u with 2" adapters. My wheels are now flush with the fender lip. This was with drop spindles, so I don't know if the tie rod clearance is a problem with stock spindles.

 

Can you tell me what brakes you upgraded to and what hubs you used? were they 1le? What offset are the wheels you used?

 

I am running C4 12" brakes with 1.7" spacers and 9" Zr1 wheels, no problems so far. They are just inside of the fender, near flush. Perfect in my opinion

 

Are your hubs made from the 10.5" rotors or the 1LE rotors?