Brake fade again

[C M Smith <cmsmith@domain.elided>]

Carbon/carbon brakes do work better the hotter they get...until they catch 
fire, then they are crap. They also have a nasty habit of exploding when 
too hot. They don't work too well then either.

Iron rotors continue to brake the car even when glowing red or, 
theoretically even white hot. Iron has to get pretty darned hot before it 
begins to flow under pressure. SAAB rally cars with more or less stock 
brakes would brake fine with the rotors glowing cherry red. The key is you 
need pad material that likes the heat.  Trouble with that is pads that like 
heat usually won't brake worth a damn when cool.

Finally, the current limitation on street brakes is selecting a pad 
material which can be kept cool enough to still brake effectively when the 
brake disc is hot while also stopping the car when stone cold. Ceramic 
rotors offer some hope there. They hold the heat much better than iron so 
temperature rises are slower, but they also tend to stay warmer for longer 
preserving the "cold" performance. Mercedes and Porsche have some nifty set 
ups.

Bottom line: iron rotors don't get too hot, but pads sure do.

Cheers (Again)


Michael Smith
White 1991 164L
Original owner
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