VIR is pretty hard on brakes

[Gray Ghost GT]

One of the best ways to help prevent your rotors from cracking is to do some slow cool down laps around the paddock to slowly bring the temperatures down, and then once you park and chock your vehicle - move your vehicle forward two feet after 5 minutes, and re-chock to move the hot caliper/pads to another portion of the rotor.

 

[Pony DNA]

I definitely agree with running brake ducting, but an additional "risk" you have to contend with at that point is rapid thermal cycling of rotors. If you go from a hard braking zone to a long straight to another hard braking zone, you're going to put a lot of fast temperature change action into the rotors that could cause them to crack--so keep an eye on your hardware between sessions.

With a simple single 3" duct to the spindles there is not enough cooling to worry about hurting vented plain faced rotors. I've been ruining spindle mounted ducts on my S197 GT for four years now with no issues. Originally I used the spindle duct setup with Teflon lined S.S. brake lines, stock calipers, OEM rotors and upgraded pads and for the last three years 14" 2-piece drilled Baer GT Plus brakes no problems. I only install the ducting for track use because the brake pads don't get hot enough to work well enough when cold and removing the ducts makes just enough difference that I don't have to change the pads.

Many historic vintage Trans-Am race cars running the historic race circuit are running two or even three large cooling ducts to their spindles with no rotor cracking problems. The seem to have picked this up from the vintage NASCAR road racers that are now making their way to these events. The NASCAR road racers are about 3,600lbs curb weight which is similar to a street S197GT.

HTH!

 

[Chris B.]

Is there any reason you are not running spindle ducts and 3" hose to the lower valance? This can make a big difference in temps, maybe 100F and your pad and rotor life on heavy cars (like stock S197) with stock brakes like you have.

I've had the Quantum Motorsports brake cooling kit on the car since last spring. It was on the car at VIR.

Wait until you go to 10" wheels in front and larger sticky tires, your brake temps will only get worse. I found that 2-piece rotors with spindle ducts improved pad life on my S197 20%-30% but you could also just use higher temp range pads.

HTH!

2 piece rotors don't seem to be very cost effective. For the price of a set of two piece rotors I can buy at least two sets of front brake pads. I already switched to higher temp brake pads than the HT-10's.