One Fast Mule

Porsche believes there's no better place to test ideas than the race track.  The 911 RSR Turbo is a good case in point, as it was essentially a test mule of a wild idea: turbocharging the 911, in anticipation of FIA rule changes in 1975.  (Previously, the only "blown" Porsche was the monstrous five-liter, 1000-horsepower 917/10 of Cam Am fame.)  To bring its 500 horsepower under control, huge tires, fenders and a massive wing were added.  The RSR Turbo placed second at both the 24 Hours of Le Mans and the 6 Hours of Watkins Glen - not bad for a mule.  But its greatest triumph was providing Porsche with the data necessary to field the highly successful 935 and the production 911 Turbo.