Dori Dori wrote:asad-Yes, iron can withstand more heat but due to the design of an aluminum rotor hat and the fact that it is aluminum, the heat dissipates faster.
Ah, but you're forgetting that iron has a lower thermal conductivity than aluminum. So given that the cross-section for conductive heat transfer into the hat is extremely small (probably a factor of a few hundred less than the cross sections for heat loss through convective and radiative cooling. So the amount of heat that gets into the hat is very small in the first place, compared to the amount of heat that the rotor friction surfaces see -- and it will be nowhere near the amount of heat needed to raise the temperature of the hat to a point where the material weakens. Temperature in this argument is a non-factor (well I suppose it actually goes against your argument for aluminum hats, due to aluminum's higher thermal conductivity, which will transfer the heat more effectively to the face of the hat)
Quote »That's why your calculations have nothing to do with the real world. You are only taking one thing into consideration and thats surface space. [/quote]I didn't take the thermal effect into consideration because I already claimed that the heat would be a negligible factor in the strength.
And believe it or not, the "filled" surface area does give an indication of the strength of that area -- and in this case the change is negligible compared to the safety margins designed in to brake components in the first place.
Quote »BTW, why did you quote me 2x.?
[/quote]Ah, I quoted that later, after the first reply.
Quote »rotor hats do see a lot of heat. That is why ustcc race cars w/ modified stock brakes usually go through wheel bearings every race and why other components become thermally stressed. [/quote]That's all well and good, but the amount of heat needed to stress a wheel bearing and the amount of heat needed to affect the strength of a flat piece of cast iron (the rotor hat) are VERY VERY different.
Quote »I still stand by what I believe. [/quote]Again, the problem is that you're "believing" rather than listening.
It's fine for you to prefer to have something that you believe is stronger (BTW, I still stand by my statement that a redrilled cast iron hat is stronger than an equivalent single-drilled aluminum hat).
But don't spread misinformation, and don't project your illogical biases onto others.
Asad