Porsche 917 ‘Interserie Spyder’

By 1969, Porsche develops the 917 Spyder with a view to competing in the extremely popular North American racing series, the Canadian American Challenge Cup (Can-Am). Three units featuring 4.5-litre twelve-cylinder naturally aspirated engines are constructed in Zuffenhausen, and Jo Siffert takes one to the US to compete in the Can-Am races, ultimately placing fourth overall. The car becomes known as the 917 PA Spyder, with “PA” standing for “Porsche + Audi” as they are the two sales organisations in the US at the time.