brake fade question @ 240 klm/hr

Joined
15 January 2003
Messages
49
Location
Canada
I had a brake problem 2 years ago.....during track day my brakes faded(totally) at aproximately 240 klm/hr.....fortunately I managed to come to a stop(via downshifting and luck)without incident. I inspected the
brakes and found that all the front pads had
cracked and the rotors suffered some scoring. I had all the rotors machined and replaced all the pads. All seemed O.K till just before storage this winter....when I noticed a brown heat checked line (1/8") on the rotor and upon inspection, on the brake pad(right front) as well. The brakes continue to work O.K. but I think I need an upgrade before I have problems. My question is should I replace all the rotors (for brake balance) with cross drilled rotors..or just the front. I'm considering using KVR rotors(told there made by Brembo) and semi metallic carbon pads all around. This mod will be both for street and track use (split about 80/20). Any advice is appreciated.....thanks, Chris.
 
It sounds like the problem you had was caused by the pads, not by the rotors.

The two most common problems of brake fade are (a) brake pads that are not designed for track use (metal masters, pads from your local auto parts store, etc), or (b) brake pads that have not been properly broken in. Regarding (b), "green pad syndrome" is very common. You have to get the pads VERY HOT a few times before they will hold up to the hot temperatures of track use. They won't get this hot from street use unless you are intentionally going out on the highway and doing a bunch of HARD 80-20 mph stops. You have to get them hot enough to fade, then let them cool down, and do it 2-3 times. If you take brand new pads (ANY kind of pads) out on the track without breaking them in, they will fade big time after a few laps. Bring the car into the pits, let it cool down for a while, and take it out again. It might happen again the second time out, but it shouldn't happen at all after that.
 
Thanks for the advice......nsxtasy. So instead of replacing the rotors, I should re machine them to get the imperfections out and install all new pads and put them through several heat cycles (break in). Any idea how many times you can machine stock NSX rotors?
 
Originally posted by CFNSX:
So instead of replacing the rotors, I should re machine them to get the imperfections out and install all new pads and put them through several heat cycles (break in). Any idea how many times you can machine stock NSX rotors?

Well, the problem with machining rotors is that they will be more susceptible to warping and hot spots, two phenomena that manifest themselves as brake shudder, when used on the track (or VERY hard braking on the street). If you're planning to continue tracking your car, I would suggest not turning the rotors every time you change brake pads; I would just leave them and let them bed in. If you have significant problems such as the scoring you mention, you MIGHT try turning them but I wouldn't do that more than once; if it happens again, I would replace them rather than turning them again.

HTH
 
I have machined the rotors already once (2 years ago) and 3 of the rotors have a excellent finish.....only the right front has a 1/8" line,upon close inspection, you cannot feel with your finger nail but you can see and it appears as a scuffing mark (perhaps heat related) on the rotor surface.
Perhaps I should go just with new pads then. Is it possible to scuff the rotor surface with emery paper? I seem to recall with my prior Corvettes in years past that the dealership, under warranty, when you had brake squeal just emery'd a cross hatched pattern on the rotors but it was such a long time ago I don't recall exactly what they did (If emery paper can be used what grade would one use?)P.S. Thanks for your input.
 
Since you can't feel it with your finger nail, I wouldn't bother doing anything to the rotors; I would just replace the pads.

You might want to check with Andie at Cobalt Friction for the pads. He's got an assortment of different brands for different purposes, offers great prices, and (since he tracks his NSX) can give you great advice on what will stand up best to track use.
 
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