Lucas_Gchips

Now once you decide to upgrade to bigger rotors, given Pad area & Compound are the same, would the Pads wear out quicker due to the Rotor running faster accross the Pads, also if this is the case wouldn't also the Pad * rotor run at Higher temps because of the increase in speed..

Secondly, with the amount of aftermarket pads that are available, why do they not publish or advertise the actual co-efficent of Friction and Basic operating temperatures??

Ash

would actually run cooler because the extra heat dissipation ability you've gained from bigger rotors will outweigh the extra heat generated by the higher speed....

Maybe manufacturers don't publish the co-efficients of friction since that would depend on both pad material and exact rotor material..of course there should be a "standard" rotor type to measure coefficient of friction against (maybe there is?), in which case we'd be able to compare coefficients between manufacturers...but what do I know...I'm just thinking out loud again!

Don't you already have big brakes for that monster of yours? I sure hope so!

Ash

Lucas_Gchips

yes I do, just to encourage a discussion on the Forum.

Bollinger

See link below. Of course, as you say, what is their reference material? Hmm.<ul><li><a href="http://www.ebc-brakes.com/autopads.htm">http://www.ebc-brakes.com/autopads.htm</a</li></ul>

Electron Man

The same pressure (force/area) applied closer to the rotors perimeter is worth more in terms of stopping power. So, I'd think a larger rotor would require fewer revs to be "stopped" even though the velocity of a larger rotor (at pad contact point) would be higher. (Assuming added rotor mass does not overcome this "benefit")

Coefficient of friction is a strong function of temperature; therefore, different standards would need to be developed (assuming they haven't already been) for street compounds -vs- racing compounds. Lack of an agreed std. temp. for the coeff. of friction value could be one reason manufacturers don't state friction coeffs.

$0.02

WClark

In fact this is the big reason for larger rotors. The added leverage of the caliper at a larger diameter is a 2 edged sword. It can add braking power but it can also unbalance the OEM intended brake bias and if you were able to overwhelm the front tires under braking before, you wont gain any useful stopping power.

That said, I went with 12.2" fronts on my A4. The larger tires I use are sticky enough that the stock brake setup even with EBC Green couldnt break them loose on a clean asphalt surface in a straight line stop. I figured that adding the larger rotor would close that gap allowing shorter stopping. The A4 is supposed to automatically compensate the F/R bias (within a limited range I am sure) according to what is needed/available. After the change I have observed that I do seem to have better practical stopping ability and based on the increase in front brake dust on the wheels and decrease on the rear I would say the car has shifted braking bias toward the front. With this in mind, I have tried a few "panic" stops on wet and dry empty parking areas and found no undersirable or unpredictable behavior.

Regarding CF publication. I know EBC published their CF numbers as well as operating temp ranges. I am sure I have seen this of other suppliers as well (maybe Hawk), but not all.

Perpetual Novice

I'm surprised no one's done an independent test.

ryoung

Yes, also the larger rotor is a bigger heat sink.

SAvant

Lucas is fishing!!! &gt;;-&gt;

Audiboy

stock. So, maybe the CTech's have the same coefficient as the Yellows, and the Stock about the Reds. Anyway, 0.47u whatever that means referenced against, it bites and grabs hard. That's with slotted rotors.

They should make rotors and pads with the same coeff as race compounds and concrete. Hmmm, that won't be good for the chassis ;P