Rule changes for the World Championship of Makes eliminated the stunning Porsche 917 during the early 1970s allowing the factory to instead develop the car for the open-top Canadian-American (CanAm) Championship in North America.

Teams from McLaren, Lola and Chaparral were attracted to the 200 mile Sprint races of the formula and the rule book permitted almost anything, including free engine displacement and the use of turbochargers.
Porsche used its new found skills with forced induction to attach two exhaust-driven turbochargers to the flat-twelve engine of the 917. The result had a displacement of 5.4-litres and produced at least 1,100 hp, making it one of the most powerful racing cars ever built. Depending on the boost pressure, the engine’s power output is somewhere between 1,100 hp and 1,400 hp.

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