Is it true that they light up when you use them? I saw this for the ceramic brakes on the SLR.

 

BTW..no one mentioned why the fact that they are lighter help..

its not just weight..like getting rid of all the extra stuff in you car to shed pounds... its rotational mass, and unsprung weight

the less you have, better you accelerate, and slow down and the easier it is to change the direction of rotation...same *** people getting lighter wheels..

yes they weigh less, but there effect is much great than that

 

Exactly!!
I'm assuming the braking power with the iron rotors is as good as with the PCCB's and if the iron's can take the heat, there really is no significant difference between the two in regards to braking ability.

The biggest difference is in the weight, like commented above.
Less unsprung weight means less work for the suspension which yeilds for better traction and overall behaviour in fast changing conditions. (bumbs etc.)
Less rotational mass means less inertia which yeilds for faster acceleration and faster deceleration.


What I have been pondering is, where does the heat go when using the Ceramic rotors. I mean, when you are braking you are basically exchanging kinetic energy into heat by means of friction (pad against the rotor). Now regular iron rotors will absorb a big chunk of this heat and the rest will travel trough the pads into the calibers and so forth.
They say "the ceramic rotors are great, they don't fade" and that's because they absorb less heat from the braking.
So if we still need to convert the same amount of kinetic energy into heat and it can't go trough the rotors, where does it go?
I would assume the balance is going trough the pads and into the calibers, brake fluids etc...?
This would mean that the rest of the system is under more stress. And I think I can notice this as always after a day at the track my pads are covered in white debris/residue that is basically burnt chemicals from the pads. And the pads also tend to crack easily (what I hear).

So are the ceramics really worth it? For better handling and acceleration propably yes but for braking it self and especially for track use, probably not...

 

Close. The ceramics don't have the thermal mass of the iron. This is no big surprise- they weigh half as much- but it means that the ceramics get to much higher peak temperatures. This is fine, because the coefficient of friction doesn't go down when they hot as with iron. It does mean that everything else gets hotter (pads, calipers) so special insulating materials inside the caliper/ pistons are required to keep the fluid from overheating.

In a heavy car like the 997tt the weight savings are small, so performance differences are harder to notice, but in a light car like mine switching to the pccbs saves 2.5% of the car's total weight, almost 15% of unsprung weight, and significantly improves the performance of the car overall. Of course that's with a car below 2000 lbs; it's harder to notice on a 997 TT or cup car. It's counter intuitive, but the place you'll get the extra speed is mostly through bumpy corners, because the lighter suspension can track the ground better...

-Pete