quote:[HR][/HR]Heh. On page 3, that guy Cobra, posts the most thorough and complete "flame" I've ever seen on the Internet. It completely disassembled the nutjob that started the thread. Beautiful, just beautiful. [HR][/HR]
Nothing like arming a salesman with just enough knowledge to stick both feet in his mouth. Of course, this is after he pulled his head from his... well, you know.
I thought this was the funniest post (from about p13, and obviously very censored):
Kevin, on the other hand. . . . Dude, what have you got going for you in life beyond being an ignorant hired hand at some little performance shop in God-forsaken Arizona? Exactly where did you earn your degree in knowing a GODDAMNED THING? You tell me how I talk so much poop, but what the hell comes from your own proximal orifice? The same thing as what comes from your distal orifice, only less opaque and in far greater quantities. I suggest you humble yourself a tad bit, and learn from what has been offered to you and the rest of the readership of this board as an educational experience. I would venture a guess that everyone who wasn't already committed either to you or themselves to buy some of your 'holy-rotors' will certainly think better of it after having read this thread and the info for which links have been provided. [HR][/HR]
So, to sum up (I guess because I didn't read every page).
Brakes depend on friction.
Friction generates heat.
This heat is absorbed primarily by the discs.
The heat is disappated by the discs.
If not disc temps remain high and pad temps increase.
Increased pad temps can result in...pad glazing, increased fluid temp and fade.
The amount of heat absorbed by the discs is dependant on the size, mass and material so larger, heavier and carbon discs will absorb an increadable amount of heat before they reach a critical temp. Now as far as disappation is concerned their is a trade off between surface area and volume. Ie if the discs are small they will not disapate the same amount of heat nearly as fast as a larger discs. That and I suspect they will get hotter faster give equivelent pad size. So I would think that smaller discs might require some addtional ventilation be it cast or drilled holes to compensate for their reduced surface to volume.
quote:[HR][/HR]So I would think that smaller discs might require some addtional ventilation be it cast or drilled holes to compensate for their reduced surface to volume.[HR][/HR]
In an ideal world this might be true but there are several things to remember:
- Drilling removes metal. Less metal means less mass to dissipate the heat.
- You spend the majority of your driving time NOT on the brakes. Since this is the case there are other ways to effectively aid in the cooling of the rotors without drilling them. On an average lap at say VIR I will estimate that I am on the brakes for a total of about 15-30 seconds of a 2:25 lap. That leaves about 2 minutes for the brake ducts to vent cool air onto the rotors to help cool them. I also brought up the point of how often do you fade your brakes on the street? If you aren't fading stock brakes do you really think there is a need for additional cooling?
- The drilling IS NOT really intended to increase cooling efficiency - that is just a byproduct of it. The drilling is to allow for gasses and dust to escape from in between the pads and rotor.
- The drilling weakens the rotor. On a larger rotor thereis more mass to distribute the forces over. Smaller rotors do not have this luxury so not only is the removal of the material cutting down on the amount of heat transfer medium but it is also cutting down on the structure of the part. On brakes this is bad.
Hope that helps a little.
Wow, sort of hoped you'd hop over and answer my question. I see your point but you might want to use "absorb" as opposed to "dissipate". The disc is absorbing the heat and removing it from the "system" while actively breaking and dissipating the heat upon release of the breaks. I was confused at first by your terminalogy. Otherwise I agree.
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