Ceramics extend life of a Porsche

By ALASTAIR SLOANE

Development of a ceramic clutch and brake discs for Porsche models was a "very expensive production process," said its chairman Dr Wendeling Wiedeking.

"Believe me, I know, I saw the costs," he said. Wiedeking, in Auckland for a few hours the other day, said the ceramic designs were Porsche patents.

"It is our licence. Everybody knows it is done by Porsche. Nobody can do it without us."

He said the cost of using ceramics in other components would be largely prohibitive for carmakers.

"Mercedes-Benz has looked at ceramics but I don't think it is doing so any more," he said.

Porsche is the first carmaker to develop the ceramic composite brake disc. It is standard on the 911 GT2 and optional on 911 Turbo and 911 Carrera 4.

The German maker says it sets entirely new braking standards, particularly when it comes to brake response, dispersion of heat, resistance to fading, weight, and service life.

They work better in wet conditions, too, and they aren't affected by corrosion from salt used on snowy European roads.

Like Porsche's conventional metal brake discs, the ceramic discs are cross-drilled and vented from inside. They are similar in size to metal discs, but are 50 per cent lighter. And unlike metal discs, ceramics are good for the car's life, says Porsche.

The Carrera GT, the limited-edition V10 supercar producing 450kW (612bhp) at 8000rpm and 590Nm of torque at 5750rpm and a top speed of 330km/h, is the first car to use a ceramic clutch.

The compact design of the double-plate dry unit helps give the GT's engine and gearbox a low centre of gravity.

A further advantage is a much longer service life compared with other alternative materials.

"Once you have built it it will never have a defect," said Dr Wiedeking.