The Porsche 917 is surely the most famous Porsche racing car, although at the beginning of its career it had the dubious reputation of actually being undriveable. The reason for the teething troubles was quite simply a time problem: with just nine months between the first drafts and presentation at the Geneva Motor Show on 13 March 1969 there was no time left for testing. The air-cooled twelve-cylinder vehicle drove straight from the drawing board to the racetrack, so to speak. The design process had focused on aerodynamics – at the expense of downforce, i.e. driving stability.