Brake cooling 101

[ho428]

68 Firebird, 11" vented rotors with single piston (for now) calipers. Can't go larger dia rotor due to HSR class rules.
Right now I have the dust shield backing plates still on, I was looking at cutting part of it out, making somewhat of a funnel and hooking 2" hose to it, my thoughts on this is it would spread the air over the rotor better rather than removing the shield and blowing air at an open area, also running a 2" to blow air on the caliper.
All this air comes from the front turn signal holes. I cobbled together a duct but haven't been able to figure out how to attach the screen so it looks good but the jist of what I'm doing is there.
The hose in the pic is just laying there, I'd have to move it up on the frame and A arm to keep it away from the tire.

Need some opinions on what I'm doing.

[Apogee]

Cool...pun intended. Most cooling ducts use some sort of "dust shield" with hose connections to push air to the center of the rotor to aid with cooling. Whether you modify an OE shield or make one from scratch, ducts can singly be one of the best modifications to any braking system, and also one of the most frustrating to package depending on the vehicle, sway bars, suspension, tires, brakes etc.

I'm curious to hear how your setup works out for you. Do you have any baseline measurements for the sake of comparison or will it be seat of the pants?

Tobin
KORE3

[ho428]

All seat of the pants stuff. I looked over several cars at the track and came up with this. Just part of the hobby to me, figuring stuff like this out.
I'm going back to the track Friday without the ducts since they're not finished, maybe I can start establishing braking points on the track to compare to when I add them.
I may also add some under the car where the mufflers would normally be and duct them onto the rear drums. Like Smokey Yunicks old T/A Camaro.
To run rear disc is an added wt penalty, with an early F-body so much wt transfers to the front I not sure rear disc would help much anyway.

[ho428]

I messed around with some screens to cover the hole. Not sure how to attach it though.
I may change all this, go to some 3" hose and recess the screen. Had several racers tell me they think it being smooth mess right over the entry that air will pass over it rather than in.
I like the way it looks though, but it has to function.

[Apogee]

A single 3" will give you more cross sectional area than (2) 2" hoses, so that's something worth considering. One 2.5" to 3" hose supplying air to the rotor is what I've typically seen work the best in the past.

I can see the concern over the mesh, but without playing around with it you'll never know. I'd probably test it out with and without the mesh, everything else kept the same, so that you can determine it's effect one way or the other. I've got this crazy idea about fabbing up a mini-wind tunnel with a leaf blower going through my head...

Tobin
KORE3

[ho428]

I've got this crazy idea about fabbing up a mini-wind tunnel with a leaf blower going through my head...

Tobin
KORE3

I had the same thought, scary.

[OLDFLM]

I messed around with some screens to cover the hole. Not sure how to attach it though.
I may change all this, go to some 3" hose and recess the screen. Had several racers tell me they think it being smooth mess right over the entry that air will pass over it rather than in.
I like the way it looks though, but it has to function.

Sweet! I like it! Looks GREAT! Hope it functions as well as it looks!

[jeffandre]

How about an exhaust-driven mini-turbo that would force air to the brakes? Probably not worth it, but it is a thought...

[jackfrost]

How about an exhaust-driven mini-turbo that would force air to the brakes? Probably not worth it, but it is a thought...

or, for that matter, an electric fan? not enough CFM?

[Randy67]

They use this: http://www.suzukaracing.com/1%20Blower.html
on Nascar cars on road courses. Should provide good cooling even at low speeds.

[HarleyR]

If you can move the ducts closer to the center of the nose the pressure will be higher... And make a piece to extend out approx 1 inch out of the outsides of the ducts to prevent air from spilling off the sides of the nose... I worked on something like that last spring at Martinsville Va and noticed on average almost 20 deg difference... Also the Pro systems brake blowers are expensive and if they get any rubber or debris in them they burn out.... Happens almost every time we run them.... You can go to NAPA and get an Atwood blower and it will accomplish pretty much the same thing.... Also some Castrol SRF.. fluid....