Brake cooling

[Al Seim]

Actually a small hole is drilled in the center of the brake pad FM and k type (I think) thermocouple is pressed in the hole and backing plate maybe .060" below the friction material rubbing surface. The wire comes out in the hollow part of the caliper piston and exits out a small slot in the contact face of the piston. That is the temp brake manufacturers are concerned about.

Not surprised. Since it's a bunch easier to put paint dots on rotor O.D. - is it possible at all to relate rotor temp to pad surface temp? They obviously relate, it would be convenient if there were some approx fixed or rule of thumb relationship.....

 

[JohnMcNaughton]

Jay L, what is the best way to determine appropiate air gap between the outer panel (the Pizza pie pan) and the wheel rim?
How much is too far, how much is not enough?

 

[Chris Schaafsma]

If the pan is under the rim size, you could attatch the thing to the outer edge with small machine screws into tapped holes.

Chris, could you feel any output air?

I use a whizz wheel to slot my pistons. 2 to 4 pretty good size slots.

Definitely

 

[danshonda12]

Dan, I have never made any but have entertained the thought more than a few times. I even bought some thin aluminum discs that I was going to make them out of earlier this year but never followed through. Maybe I will this next year. Noy sure how the aluminum would hold up in the long term, but we're not 'supposed' to be hitting things with our wheels anyway. :roll:
I know of a few other prod racers that use them to good effect, Chuck Mathis being one. He has some REALLY nice carbon fiber ones that he makes for his VWs. Find some pics of his car, both the Rabbit and his newer Scirroco and they are obvious on the front wheels.

I also ran across this photo sequence of some that were made for what looks to be a rally car, also Carbon Fiber. Not the best pics but the best I could find at the time.

Thanks!

 

[danshonda12]

Thanks everyone for all the advice/ideas.

 

[Larry Frankenstein]

Larry F. asked:

"Re fancy thermal barriers. Any specific recommendations?"

Years (decades?) ago I used a 2" fibrous asbestos tape material between the metallic thermal barrier and the pad. Remember it would char in a circular ring where the puck contacted the metallic barrier.

Asbestos NLA, but high temp, ceramic fiber material is. McMaster-Carr #87575K83. .032" thick, -300-2300 deg., 0.38 Btu/hr. x in/sq. ft., 12 lbs/cu. ft. $24 for 3" x 50 ft roll.

Have seen it used as welding mask effectively. Very similar to old asbestos material.

RJS

I thought Jay was referring to a coating in/on the piston.

L