Porsche is currently evaluating whether to install a PDK transmission into the Porsche 911 GT3 vehicle due in 2013. August Achleitner, the 911 project chief, said that company’s motorsport division is testing both manual and PDK versions of the GT3. Achleitner, however, said that only one gearbox will offered for sale, adding that the PDK is favoured to be used on the GT3.
This might be attributed to the fact that the manual 911s are not so popular, currently accounting for only 30% of sales. It was a different story for the non-manual 911s. "When we launched the 911 Turbo S, we did not offer a manual, but we have not had a single complaint," Achleitner told Inside Line. With this development, the GT3 is expected to carry a PDK gearbox.
Meanwhile, Achleitner confirmed that the GT3 and GT2 will feature a variant of the electromechanical steering system that the new Carrera uses. The steering system has been receiving criticisms for providing less driver feedback than a traditional hydraulic setup. Achleitner, however, defended the system. "The new system only removes the feedback you don't need," he said, adding that it is preferred by all of the team’s race drivers.
For the 911 GT3, Porsche decided to develop a completely new engine – a six-cylinder naturally aspirated engine with direct petrol injection. This engine also features titanium connecting rods, forged pistons and dry sump lubrication. Since this engine is a high-revving unit -- up to 9,000 rpm – it allows the 911 GT3 to be very competitive on the track with its broader engine speed range. Porsche 911 GT3’s new engine is derived from the six-cylinder found in the current generation of 911 Carrera.
It was structurally modified to make sure that the 911 GT3 becomes an enhanced high-revving machine. Because of its high engine speeds, revolutions remain in the max power range even after shifting up. This allows the new engine to develop 475 hp (350 kW) of max output at 8,250 rpm and 440 Newton meters (Nm) of peak torque available at 6,250 rpm.
In this configuration, the engine could reach the max speed to 9,000 rpm, allowing the 911 GT3 to achieve peak performance values among road-going vehicles. On the horsepower to liter basis, the six-cylinder in the 911 GT3 has a power-to-displacement ratio of 125 hp per liter.
This engine sends power to the wheels through a Porsche Doppelkupplung (PDK) dual-clutch transmission that is originally developed for racing. PDK allows better and faster response from the drive system sans any interruption in propulsive power. PDK takes cues from the sequential gearboxes used in motor racing, which means it could bring more advantages in terms of performance, dynamics as well as driving enjoyment.