Has anyone used coatings on certain brake components to keep the brake system cooler?

 

hmmmmmm... The heat goes by conduction from the pad/rotor
face to the disc, and to the brake pad, fluid, and caliper. The
place I'd consider is a ceramic coating on the fluid-facing part
of the pistons, and both the piston wall and caliper wall.
However, you fundamentally aren't lessening the heat,
which *will* be generated by braking, corresponding to
the weight of the car x the drop in speed, so if you insulate
one area, you just force the heat to increase elsewhere.
The pad will stay hotter, and the disk will get hotter. This
may be why we don't hear much about htis being done.
It is probably better to concentrate on dissapating the
heat with air flow.
Joe

 

Joe,

I didn't even thinkabout it until I saw it discussed by Swain www.swaintech.com Then click on "Racing" and then "Automotive Coatings." They are saying it helps prevent the brake fluid from boiling.

They talk aout a Thermal barrier coating on some parts to keep heat away and a Dissipant Coating on other parts to dissipate heat. Go to their price list and it appears they are coating calipers, back of pads, pistons and rotors.

 

I'm with Joe (very interesting post as usual from him) on this. I think you already have the brake cooling ducts since you were the one that discovered them What brakes do you have and are they slotted rotors or?

 

Chad, I'm a chemical engineer and understand thermodynamics thoroughly. I would like to really understand what components they want to coat. Joe is correct here and I would need more info to see if what they are saying makes sense.

 

Ive used swaine on many internal engine applications in the past, they know there stuff. I would just give them a ring or write then an email, im sure they will give a more then informative answer.

 

I think you can put some coatings that might help to dissipate heat better then stock but I dont think it would help that much. The only thing I can think of is a coating on the calipers that makes the radiative heat losses greater. You could put a heat shield inbetween the rotors and brake lines to prevent a little heat from getting to the lines. Without more info I dont really see the benifit of coating the brakes.

Any updates on KA?

 

Wouldn't it make sense to ceramic coat the back side of the pad? I am referring to the steel pad backing plate. I would assume this would function similar to the tiles on the space shuttle (when they work that is!! ) I would think that it would create a barrier against heat absorption by the pistons, caliper and, in turn, brake fluid.

What are the holes in this theory??

Here I am, standing at attention, ready to be shot down!!

 

I agree with your point on the ceramic coating. I never thought about coating the back side of tha pads with anything. I know on computers they put a paste inbetween the CPU and the heat sink, to fill all the gaps and allow for a better heat trasfer coefficient. Using the same kind of idea someone could put a sort of paste or gel type medium that would increase the contact between the pads and calipers so that the calipers could cool off the pads.

Or that the pads are transfering heat to the pistons and then to the fluid. Insulating the pads then makes sense to me.

 

For that matter, why not make the backing plates out of ceramic. From a structural persepctive, I can't see any reason you wouldn't be able to do that. They are simply in compression.

The intent with this idea is simply to insulate the piston+caliper+fluid from the hot pad. This is exactly how the shuttle survives the heat stresses of re-entry into the earth's atmosphere without buring up the occupants or the cargo.

Think of the system this way:

• Heat producing rotor/pad frictional interface = the heat producing air/shuttle skin frictional interface
• Ceramic backing plate = the shuttle tiles
• Pistons, caliper and fluid = the shuttle occupants and cargo.

 

I do not see a reason except for price on why they dont make the backing plates out of ceramic. Do you think there is any shear caused by the pad inbetween the rigid caliper and rotating rotor?

 

Red,
I was minimizing the effects on the backing plate for convenience. There are other forces at play of course, shear being one of them.

My point is....regardless whether the backing plate was ceramic coated, a steel plate encapsulated in a ceramic or completely ceramic, conceptually it should ward off excessive heat gain by the pistons, calipers and fluid.

 

Ken I agree with your point about warding off heat. My background is chemical engineering, so I do not have a background in structural or material engineering. Since I am not familiar with ceramics I was speculating that the backing plates are made from steel to deal with the forces acting on it.

It would be interesting to see what some race cars do with their brakes, besides air ducts.

 

Ken, people often install titanium backing plates (me included) behind the pads to help thermally isolate the pistons/fluid. Your idea is correct, I just don't know how much a ceramic coating there will help. The second concern is the brittleness of ceramic against the pistios.