Quote:
Originally Posted by robc
Sort of, in a closed system yes, kinetic energy is all that matters mass * velocity = X no matter whether it takes 5 seconds to go from v1 to v2 or 10 seconds. However -- you have significantly less time to cool if you are on the brakes too much.
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Convection rate <<< conduction rate, and as I said above, the heat you are transferring into the environment via convection
while braking is negligable unless you really are sitting on the pedal for a much longer time than you need to, but who brakes that way anyway? You'd be going painfully slow.
Quote:
Originally Posted by robc
My statement is simply that as I got faster (better lap times), I was on the brakes for a shorter duration into each corner, and I had lower brake temps -- measured with an infrared thermometer adjusted for track temp and cool down lap times. I did say that I had lower brake temps when I was "faster" -- meaning faster lap times, so, yes, I was "putting in slow laps", that was my assertion.
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My point is that you were converting less kinetic energy to heat as you starting going faster (you were braking LESS and scrubbing less speed). That IS the explanation for why your temps were lower as opposed to the specific of your deceleration rate and the time you spent on the brakes (yes, they are related to how much kinetic energy you are losing).
Quote:
Originally Posted by robc
Second theory: temperature created at lower pedal pressure for longer (lower pad to rotor pressure) actually creates higher temperature than higher pressure for shorter duration due to unknown (to me) properties of brake pad material.
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What is the basis for this theory??? I don't see any.
Quote:
Originally Posted by robc
I do not know how long it will take to reach the max temp (is that what MOT means?) of the RS19's (1382F/750C), but the hottest temp I ever was able to record was at Laguna Seca with no cool-down lap, 1000F -- and there did not seem to be any damage to the pads, I went on to use them for another 12 days or so. Longest session in normal events is 35 min, and that has not been a problem temp wise since I "learned" to drive the car.
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I saw 610C at the paddoc at Watkins Glen. My Pagids held up, but wore down.
I am not familiar with West Coast tracks. How many major braking zones, and what were the top speeds you were reaching before them (corner entry speeds would help as well)?
MOT is max operating temp. The sustainable limit for the RS19s is 700C. 750C is for a very short period of time, meaning it is probably pretty close to breaking down at that point.