Porsche’s latest 911 might look virtually the same as the previous model, but it’s beneath the sheet metal where the big changes have been made, writes Ian Adcock.
Go deeper with GlobalData
It has taken Porsche 25 years to productionise its ‘Doppelkuplunsgetriebe’ [double clutch transmission] since launching it in the Le Mans-winning Porsche 956 Group C car, but it has been worth the wait.
The seven-speed PDK differs from those used by VW-Audi and Ford, in that it features a wet clutch system to cope with the torque created by Porsche’s engines. A big challenge for Porsche and its technology partner, ZF, was developing an effective seal between the gears and clutches to prevent contamination and the two different lubricants mixing.
Speaking to just-auto, Porsche director responsible for engineering, Wolfgang Dürheimer said the PDK could cope with all future torque demands including the hybrid Cayenne and Panamera.
The gradual introduction of the PDK spells the end of Porsche’s Tiptronic auto, whilst its semi-modular design means that a lower spec, six-speed version will appear in the Cayman and Boxster at some future point.
Porsche’s iconic flat-six engine has also been given a complete redesign enabling it to be fitted with direct injection for the first time. This first generation DI system uses pre-, main- and post-injections at high load and low engine speeds for increased comfort. Currently, it’s a conventional pintle and spring injector as the current piezo ones are too long.
However, August Achleitner, responsible for engines, said the second generation direct injection systems would feature five holes within one to two years.
He also fired a warning shot to the injector suppliers.
“Multi-hole injectors are difficult to manufacture, but it can be done transferring diesel know-how to petrol injectors. The suppliers need to learn how to do this. And we will need piezo injectors when we go to stratified charge,” he said.
Currently the Porsche DI system is homogeneous charge.
Ian Adcock
