Fever machines: Porsche 917/10

Submitted by Rich Fowler on July 20, 2010

Porsche’s fearsome 917 sports-racer came, saw and conquered during the first two world sportscar championship seasons of the 1970s. The 4.5-litre, flat-12 cylinder machine – later increased to five litres – was the most sophisticated produced by the German marque, thanks to its prodigious power output and slippery shape.

Victory in all the major endurance events of the period, including Le Mans wins in 1970 and ’71, meant its iconic status was assured in perpetuity. Very few enthusiasts would leave the 250mph rocketship off their list of absolute favourite – and most beautiful – racing cars. It’s at the very top of mine…

Sadly, the imposition of a three-litre-maximum-engine-size regulation for 1972 meant the 917 and its equally potent and head-turning rival, Ferrari’s 512, were confined to the museum. While Ferrari committed to the new-look world sportscar championship (and cleaned up with the three-litre 312PB), Porsche shifted its focus to Group 7 – for anything-goes sportscar racing on both sides of the Atlantic: the Canadian-American Challenge in North America and the Interserie championship in Europe.

The new derivative of the 917, dubbed 917/10, was an open-cockpit (Spyder) projectile that featured lighter components and a larger fuel tank for long-distance events. It had made its first appearance in 1971 but struggled against the alloy-block Chevrolet V8-powered McLaren M8s. In fact, the British-built cars had dominated Can-Am, winning as they pleased from 1967 to 1971, losing only four of the 43 races during that time.

Porsche’s solution to the problem for 1972 was to fit a turbocharger to the five-litre flat-12 engine in the 917/10. The forced-induction modification pushed the car’s power output to a staggering 900bhp. The two brave drivers charged with taking the fight to McLaren in this new super-Porsche were Americans Mark Donohue and George Follmer. A set-back in the shape of a massive pre-season testing accident for Donohue effectively reduced the assault to a one-man show, but Follmer proved more than capable. He dominated the championship, taking five wins to comfortably break the five-year McLaren monopoly on Can-Am titles. Across the pond in Europe, the 917/10 took a one-two in the Interserie campaign, Leo Kinnunen heading home Willi Kauhsen with seven wins from nine races between them.

This fantastic sports-racer continued to win through until 1975, although by ’73 attention had turned to a more ambitious creation. Yup, Porsche pushed the boat out even further when it introduced the mind-scramblingly powerful and dominant 917/30. But I’m saving the story for another time…