Brake Pad: Description and Operation
Porsche Ceramic Composite Brake (PCCB) - Boxster S
The Porsche Ceramic Composite Brake (PCCB) is available as an option (I no.) for the first time for the new Boxster S (987). The PCCB provides further enhanced performance in comparison to the standard brake system of the Boxster S.
The main advantages of the PCCB are:
- Faster response
- Very high fading stability thanks to consistently high friction values
- Large safety reserves, even under extreme loads
- Reduction in rotating and unsprung masses in comparison to grey cast iron brake rotor of the same type and size
- Very long service life according to respective conditions of use
- Absolutely corrosion free
The PCCB is the result of years of experience on the part of Porsche as a technological leader in the field of brake systems and is based on carbon fiber reinforced ceramic brake rotors with inner cooling ducts with an optimized shape as well as specially matched brake pads made from a composite material. The ceramic brake rotors are manufactured by silicating specially treated carbon fibers in a vacuum process at around 3092 °F. (1700 °C).
The ceramic brake rotor used for the first time in the Boxster have been further optimized. The most important changes concern the shape of the inner cooling ducts and the material composition: the familiar evolute shape of the inner cooling ducts has been modified to increase the ventilation effect of the rotating rotor. This results in an even higher air flow and a subsequent improvement in brake cooling. Finally, optimization of the fiber reinforcement has led to a further marked improvement in abrasion resistance, particularly when the brake is subjected to high loads. For the customer, these improvements mean increased performance and an even longer service life for the brake system.
Together with the newly developed brake linings, the ceramic brake disks of 350 mm in diameter ensure very high and above all constant friction values during braking. With the support of 6-piston aluminium monobloc calipers on the front axle and 4-piston calipers on the rear axle, brake response is even faster and more precise while requiring markedly less force to be applied to the brake pedal.
The PCCB sets definite standards in the areas of weight, fading stability and responsiveness.
The ceramic rotor is perforated (cross drilled) and internally ventilated like conventional grey cast iron brake rotor, but weighs only around half as much as a grey cast iron rotor of the same design and size. Since this weight reduction refers to the unsprung masses, as well as having a positive effect on the power-to-weight ratio and fuel consumption it also improves driving behavior with regard to handling, road holding and comfort.
The PCCB retains its excellent fading stability even under extreme loads to offer a high level of safety, particularly when braking from high speeds. The new brake system also exhibits excellent characteristics in relation to braking response with considerably reduced pedal force requirement.
A further decisive advantage of the PCCB is its long service life. Abrasion of the ceramic brake rotor is exceptionally low due to the rotor's extreme surface hardness in comparison with a grey cast iron brake rotor. The new brake pads also have a long service life. However wear on the components of the brake system, particularly pads and brake rotor, is very much dependent on how the vehicle is driven and the conditions of use and cannot therefore be expressed in the form of a guaranteed mileage.
As a result of its great fading stability and particularly its very low weight, the PCCB is ideal for use at high temperatures and even for driving on the circuit. It is on the circuit or as a result of similar extreme driving on normal roads that wear on the brake, and in particular on the brake pads, will increase sharply. After use on race tracks, expert inspection is necessary in the same manner as applies to the high-performance brake made of steel, replacing components as necessary.
As a technical innovation, the PCCB offers a high level of quality, safety and driving pleasure, even under extreme driving conditions, thanks to its characteristics of reducing the unsprung weight, its consistently high friction values and its low wear.