Brake Ducting

As part of changing my uprights I had to design new brake caliper mounting adapters, so I came up with a design that I could add a brake duct to. I've already been running these brakes on my old setup without ducting and they actually didn't fare too badly (time attack stints aren't very long) but figured it was worth designing them so that I have the option at least, as I'm planning on going a bit faster on the new setup :)

So here is my design. I guess I'm after a bit of feedback from those who have added brake ducting. These tubes are 2" (it's about as big as I could fit in the space) and I was going to connect these to intake ducts from the front of the car via SCAT tubing. Will 2" be an effective size? Do you think the positioning of the duct will be effective to actually cool the brake rotors or does it need to be directed in some other way? I figured having the air flow in to the centre of the rotor is best so that the air flow through the vanes to cool the rotors down as opposed to just blowing on the surface of the rotor.

Thanks in advance!

Hi Nick, you're on the right track. The discs work more or less like air pumps when they spin, so you definitely want to feed the air to the inside of the disc, not the face. The other thing you want to think about doing is sealing the areas of the inside of the brake disc to help make sure all the air from your ducting makes its way through the inside of the disc rather than escape, I've added an example of what I mean below. Keep the sealing plate as close as you can to the disc, ideally within 2-3mm clearance max.

As to whether 2" is enough diameter for the ducting, that's really difficult to say without knowing more about your application. I've worked with cars with no ducting at all with brakes that work great, and some with 2x 4" ducts on each corner of the car that have brake cooling problems!

If you're doing sprint racing on a medium weight GT style car, a 3" duct is probably a good starting point, to give you an idea. The place you feed the duct from makes a big difference as well. Take it from a nice clean cold source at the front of the car with generous radii on the inlet.