Disc Brake System: Description and Operation
Porsche Ceramic Composite Brake (PCCB)
The Porsche Ceramic Composite Brake (PCCB) is available as an option for the first time for the 911 Carrera and 911 Carrera S.
The PCCB provides increased performance in comparison to the standard brake system.
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
- 50 % reduction in the rotating mass and unsprung weight compared to cast iron brake discs of the similar construction
- Long service life of brake components
The PCCB is the result of years of experience of Porsche as a technological leader in the field of brake systems, and is based on carbon fiber-reinforced ceramic brake discs with evolvent cooling ducts as well as specially matched brake pads made from composite material. The ceramic brake discs are manufactured by silicating specially treated carbon fibers in a vacuum process at around 3100° F. (1,700° C.).
The brake package comprising of ceramic discs with 350-mm diameter for all four wheels and the composite brake pad, together with the 6-piston aluminium monobloc fixed calipers on the front axle and 4-piston aluminium monobloc fixed calipers on the rear axle, ensures high and, above all, constant friction values - whether the brake system is hot or cold. This provides a good foundation for a short braking distance even under very high loads.
The brake discs are equipped with several small arch-shaped cooling ducts. This results in greater rigidity and improved cooling of the brake disc.
The PCCB sets definite standards in the areas of weight, fading stability and responsiveness. The ceramic disc is perforated and internally ventilated like conventional cast iron brake discs, but weighs approx. 50% less than a cast iron disc of the same design.
Since this weight reduction refers to the unsprung weight, as well as having a positive effect on fuel consumption it actually improves driving behavior with regard to agility and handling.
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 brake system also exhibits excellent characteristics in relation to braking response with considerably reduced pedal force requirement.
Another advantage of the PCCB is its long service life. Abrasion of the ceramic brake disc is exceptionally low due to the disc's extreme surface hardness in comparison with a cast iron brake disc. The new brake pads also have a long service life. However wear on the components of the brake system, particularly pads and brake discs, is very much dependent on how the vehicle is driven and the conditions of use.
As a result of its outstanding brake fade stability, and particularly its very low weight, the PCCB is ideal for use at high temperatures and use on race circuits. It is on the race circuit or as a result of similar extreme driving that wear on the brake, and in particular on the brake pads, will increase sharply. After an intensive weekend on the race track, as in the case of high-performance steel brakes, the brakes components will need to be checked for wear and replaced 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.
