Experiences with brake cooling...
02-20-2006, 08:15 PM
#16
Technical Specialist
Rennlist
Lifetime Member
Rennlist
Lifetime Member
Compared to 89 and earlier 911's, brake cooling on a 964 is a royal pain. 993's even have it easier (the referenced link above works on a 993 because of additional space in the wheel well that 964's don't have).
As one person noted, a popular choice is to replace your fog lamps with scoops and run hoses to the wheel well. Some kits include a piece to direct air towards the rotors. I added some aluminum pieces that effectively extend the stock rubber air directors higher, to catch all the air coming out of my front scoops (have to be very sure under all conditions that any air director extension will never contact the brake hose). Even so, this is pushing air towards the rotor, as opposed to feeding air into the center of the rotor, ala the pre-89 911's. If you really use your brakes, you'll see differences between the hotter outside and the cooler inside brake pads.
Some have mounted scoops under the car, as one person showed above, and run hose over the air arm towards the eye of the rotor. There's also a fiberglass kit that some have used or tried to use - I've seen it and wouldn't use it myself.
Porsche has said for years that it's wheels were designed to help move air through the brakes to assist with cooling. It will be interesting to see how the Jongbloed wheels work for Tom, hopefully they do the trick nicely.
Certainly moving to larger brakes helps with heat capacity - most who put Big Reds on, with minimal cooling, don't seem to run into heat-related issues. Another thing that can be done, as Marc did, is install titanium plates between the pad and caliper pistons, as titanium doesn't transfer heat well. Some have gone to the Castor SRF brake fluid, which is pricey but works, too. Oh, and removing the stone shield is a first step to get more air to the rotors.
I think my next step is to get a set of the pre-89 a-arm scoops and some hose....more air is good.
As one person noted, a popular choice is to replace your fog lamps with scoops and run hoses to the wheel well. Some kits include a piece to direct air towards the rotors. I added some aluminum pieces that effectively extend the stock rubber air directors higher, to catch all the air coming out of my front scoops (have to be very sure under all conditions that any air director extension will never contact the brake hose). Even so, this is pushing air towards the rotor, as opposed to feeding air into the center of the rotor, ala the pre-89 911's. If you really use your brakes, you'll see differences between the hotter outside and the cooler inside brake pads.
Some have mounted scoops under the car, as one person showed above, and run hose over the air arm towards the eye of the rotor. There's also a fiberglass kit that some have used or tried to use - I've seen it and wouldn't use it myself.
Porsche has said for years that it's wheels were designed to help move air through the brakes to assist with cooling. It will be interesting to see how the Jongbloed wheels work for Tom, hopefully they do the trick nicely.
Certainly moving to larger brakes helps with heat capacity - most who put Big Reds on, with minimal cooling, don't seem to run into heat-related issues. Another thing that can be done, as Marc did, is install titanium plates between the pad and caliper pistons, as titanium doesn't transfer heat well. Some have gone to the Castor SRF brake fluid, which is pricey but works, too. Oh, and removing the stone shield is a first step to get more air to the rotors.
I think my next step is to get a set of the pre-89 a-arm scoops and some hose....more air is good.
