Porsche’s PDK dual-clutch automatic transmission has become a staple of the automaker’s lineup, displacing manual transmissions but also offering quicker shifts and therefore quicker lap times. An engineer named Rainer Wüst is responsible for this.
According to a Porsche press release, Wüst joined the automaker in 1971 as a transmission test engineer. About 10 years later he was put in charge of the first PDK development program.
“The idea was to combine the best of two worlds,” says Wüst in a statement, “the efficiency advantages of a manual transmission and the performance potential of full automation.”
Porsche 944 Turbo PDK development mule
The idea of a dual-clutch transmission actually goes back even further. Engineer Imre Szodfridt built a prototype in the 1960s, which Wüst and his engineering team dusted off and used as a starting point.
“We took the Szodfridt gearbox from storage and worked with pneumatic valves, which we converted to hydraulic,” he said. Based on this, they developed a prototype that was installed in a Porsche 944 Turbo. But the head of development at the time, Helmuth Bott, also wanted to test the new transmission in racing, so it was also used in the Porsche 956 and 962, which dominated sports car racing at the time.
The addition of paddle shifters, a tweak Wüst credits to racer Hans-Joachim Stuck, meant drivers didn’t have to take their hands off the wheel to shift gears. The PDK transmission also made left-foot braking easier, allowing drivers to keep the 956/962’s turbocharged cranked up at all times. However, the gear changes were very rough, which put a lot of strain on the transmission. It also ruled out the use of road cars for the time being.
Porsche 962 C equipped with PDK gearbox
On the racetrack, Stuck and Derek Bell won the 1986 World Sports Prototype Championship race in Monza in a PDK-equipped 962 C. Previously, Walter Röhrl won the Semperit Rally in late 1985 in a PDK-equipped Audi Sport Quattro S1. However, despite these racing successes, the technology of the 1980s was not advanced enough to use the PDK in production cars.
“We were at least 20 years ahead of our time,” said Wüst. Components like valves and electronics weren’t where they were needed for series production, and Porsche lacked the technology to develop a wet clutch that would have allowed for smoother shifts, he noted.
Of course that would change at some point. After two decades of technological advances, Porsche introduced its modern PDK gearbox as an option in the 911 in 2008 – and it hasn’t looked back.
