Juhatee

I'm using C6 Z51 discs in rear. The car is a C5.

Rear brake temps were quite high compared to front ones (Stoptech 2-piece 360 mm discs with hub ducts). I can not use C5Z rear ducts because of 335/30-19 tires. I was going to do different ducting but I noticed these C6 Z51 discs take air from the wheel side, not the inside..

How have you people done this?

road pilot

Please tell us what the problem is with the rear ducts???
You know you can heat them and bend to suit your needs.

Juhatee

Rear tire is so close to frame that I don't know if I can make those ducts fit. I can try though.

But after that rear ducts direct air to wrong side of brakes. There's no air passage on inside of the rotor, at least not in C6 Z51 rotors.

z06801

do you run in competitive driving mode or with everything off?

Juhatee

That's a good point. I drove with active handling and the track was wet. Perhaps that was the main reason for rear brakes to heat so much.

But I'd still want to know how ducting to rear hubs from drive shaft side would work. These rotors flow from wheelside to outer diameter..

LEAVINU

How vital is rear brake cooling is my question (in ALL cases not just the OP's)? With so much bias up front is it really necessary for those not running pure wheel-to-wheel?

Juhatee

Well my front brakes were 375 F and rear brakes were 620 F. Ambient temp was 50 F. These brake temps were measured at the pits, which included almost 2 miles of slow driving before measurements.

Of course I need another track day with dry tarmac so I may drive agressive without active handling. After that I know for sure what will the temperature be.

I was testing my car at the track keeping in mind that I might have bad brake bias because of having C5 front calipers in rear and Stoptech ST40's in front. I didn't find any oversteer in brakings or things like that.

ErnieN85

Ok here are, some ideas stock C6 Z51 brakes are vented from the wrong side
so ducts will not help much. posssibly DBM rotors may be vented on the right side. you could also use front rotors and brackets on the rear however you would lose the emergency brake
if you have to pass a street inspection that might not work

LEAVINU

I run Wilwood rears so they are seeing some benefit then I guess, but it seems only when AH intervenes is when folks see excessive rear brake temps/wear. Without AH are the rear brakes really needing the cooling ducts?