Latest Brake Development

There's relatively less throughout for brake discs during the past 20-30 years. The most powerful disc brakes are still ventilated, cross-drilled and made of cast-iron, although larger wheels enable larger diameter of brake discs.  For calipers, road cars today still employ single caliper per disc. Each caliper is actuated by up to 4 pistons ("4-pot") or a few racing-biased cars may even employ 6-pot calipers. The caliper is made in a single piece - so called "monobloc" - and made of aluminium.

Cast-iron, aluminum and carbon-fiber discs Obviously, cast-iron disc is the heaviest part of a brake - about 8 kg each, or 32 kg per car. Aluminium alloy discs are used in the base Lotus Elise. Though light, they were less resistant to heat and fade, thus more powerful Elises still employ conventional cast-iron disc. In contrast, carbon-fiber disc is most heat-resisting yet is by far the lightest, however, it requires very high working temperature, otherwise braking power and response will be unacceptable. (it's expensive as well) It was first introduced in Formula One, but applying to road cars seems impractical (F1 cars have warm up lap to bring the discs into appropriate working temperature), although the short-lived French sports car specialists Venturi made history by applying it to its road cars in the mid-90s.

Porsche's ceramic disc brakes Recently, Porsche introduced a breakthrough to the 996 Turbo - ceramic disc brakes. Ceramic disc is highly heat and fade-resisting. Moreover, it is just 4 kg each, or half of a conventional cast-iron disc, thus save 16 kg per car. This benefit performance as well as ride quality (because of lower unsprung weight). The ceramic disc is based on specially treated carbon-fibers that are siliconized at 1,700°C in a high-vacuum process. Accompany with a new metallic brake pad, Porsche claimed it provides superior braking power yet requires less effort, thus does not require brake assist. The pad does not absorb water, hence excellent response under wet conditions.