Brake pad selection

What do you think the average temperature of a rally car's brakes are? If you run Wilwood pads, what compound do you run? I'm pretty sure I want to run the A compound, but I'm not sure. Any thoughts on this? This *is* taking into account the transit stages and other times when braking wouldnt be done "red hot"

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Welcome to the cult of JVL drink the koolaid or be banned.

I think it depends on a LOT of variables.

Car weight and weight bias
Driver technique..do you coast into a corner or full throttle in and brake hard?
Type of stage...fast, slow, twisty, uphill, downhill?
HP of car?
Diameter of brakes and rotor thickness
Ducting to brakes

Any of these can change the final temps by a lot. There are some stages where you almost never touch the brakes, and others where the rotors will be absolutely glowing red hot. Can be anywhere from 600 degrees to 1300 degrees F!

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Opel is a 4-letter word...
http://www.flickr.com/photos/10498579@N07/sets/

Hmm. I was looking for more of a baseline sort of setup. Thanks though!

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Welcome to the cult of JVL drink the koolaid or be banned.

I think all of mine are D compound. We'll see how it lasts. I'll probably look into other options from Hawk or Porterfield for the next set. The front pads were free and the rears were cheap.

Can't really say how they'll do, but they work well around town. Feels like a stoppy at times.

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Grant Hughes

We have used Hawks and Porterfields. The Hawks just chewed the daylights out of the rotors; we stopped at one finish control and the timing volunteer said "DO you know there are sparks flying off your rotors, and you're not moving?!?" The Porterfields don't chew up the rotors, but stop as well; several folks have reported this same thing over the last coupla years. The R-4 compound is used by many rally folks; they work better when warmed up a bit, but it's not a bad situation on cold pads.

We also use KVR's in the rears of one car to maintain good bias balance; they fade easier, don't chew the rotors, but always recover. They would be fine on rear barkes if you can account for the fading on long stages, and would be fine IMO for rally-x use.

Do you have the stock braking system, including the stock proportitioning?

Regards,
Mark B.

I've always enjoyed Porterfield's R-4 compound.
They bite well enough when cold, do not eat up rotors and wear well.

The Volvo would use up a set of brake pads in a week-end with stock size rotors and calipers.

High temp fluid would boil before the pads would fade.

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JohnLane

Overkill is consistently more fun

I'm building a dual master cylinder system with a handbrake plumbed in.

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Welcome to the cult of JVL drink the koolaid or be banned.

I like R4's a lot, but you've gotta keep an eye on them. They work really great in a rally application, where they start out cold(ish) at the beginning of a stage, work up to being glowing hot, and then get to cool down after the stage is over. I've been running them for several years on my GTI with no problems.

A few years ago, though, over a period of several events I tested a variety of pads on my Miata track car. During one of the longer (40min) heats I was running R4s and was stuck in traffic (nose-to-tail) most of the time so I wasn't getting very good cooling. The last couple of laps I had a mushy pedal - my brake fluid was obviously boiling. Now I've run ATE SuperBlue for years without having that happen, so I know they were HOT. Well, when the heat was over, we let 'em cool down and then went to change the pads and bleed the lines. The pads pretty much just crumbled off the backing plate. I'd never had that sort of problem with them before so I was sort of surprised.

Now, that sort of extended cooking doesn't really happen in rally, but it's something to keep in mind.

(FWIW, the pads I ended up running on the Miata are Cobalt Blues, which suck when cold and eat the rotors like crazy, but they'll stop you on a dime even when they're at supernova temperatures. Also, they throw neat blue sparks when you're bedding them in...)

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Self-righteous douche canoe