Porsche Doppelkupplung: Porsche 911 - Version 2.000 Porsche Doppelkupplung: Porsche 911: Did you know that Porsche Doppelkupplung (PDK) was originally designed and developed by Porsche for motor sports in the 1980s and was eventually integrated in the 911s in 2008. PDK is optional and comes in both manual and automatic mode cars. For more information read this free ebook.