Pad manufacturers show mu vs temperature charts.
I assume that's the temperature of the rotor?
Hey there
That's how I've matched up my pads and rotors by using Genesis temperature paint on the end of the rotor at the vanes.
You get the max rotor temp with the paint and then get a pad that has a range where that rotor temp lands somewhere within that range.
Rotors are being actively cooled and have much more mass than the pad. So your pad temp will definitely be a decent bit higher than the rotor temp, which is based on... variables.
Ever notice how a pad compound that's borderline on fade works great when the pad is near new and has a lot of mass to damp out the temperature spikes in braking zones, but as it wears down it's much more likely to fade? This is due to there being much less pad mass to absorb those spikes of heat input, so your max pad temperature is going up as they wear down. So you can see that even on the same sets of components, as everything wears, the amount the pad will be hotter will vary over time.
My best guess based on a few temperature measurements and seeing pads fade is that the peak pad temp ranges from 200-400 deg F over rotor temp.
I know the thermal variations of the pad and rotor are quite dynamic. But isn't the pad material much less conductive of heat than the rotor?
So I'd think the pad material will stay lower than (not above) the average rotor temperature, where as the rotor temp will rise/fall quickly in hard braking zones.
As pads get thinner, yes, they have less thermal mass, so, I could see the average pad temperature running closer to the average rotor temperature as they get worn.
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And of course, depending on light, it either looks beige or yellow-green. UG.
I'm hard pressed to believe I'm getting to 800C temps, even on a 100deg day.
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I already had all this shit on m3forum.net so I don't want to post it all again, but I'm on HAWK DTC-60 pads up front and they're perfect with these 993TT Brembos fronts and DTC-30 pads in the rear on 996 Brembos.
Fronts:
Rears:
Kinetic energy is converted to heat energy at both the rotor face (which is continually moved away from this heat flux interface), and the pad face which just stays there and heats up. The rotor is more conductive, but all that means is it'll move the heat via conduction across its whole thickness easier than brake pads. Hence your pad interface temps definitely being hotter than the rotor temps.
I've definitely nuked/badly faded 1200-1300 F MOT pads with rotor temps that were about 750-800 F after a really quick half lap cool down (so probably seeing 900-950 F in braking zones).
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