Nine seventeen! Two words that spell out the best of the big racing sportscars. Two words that conjure up images of a Pedro Rodriguez Gulf coupe averaging over 160 mph at the formidable Spa-Francorchamps circuit in 1971. Langhecks (longtails), running at over 240 mph down the Mulsanne straight at Le Mans; eleven hundred horsepower unleashed in a bellowing, flame-spitting, turbocharged monster at Laguna Seca in Can-Am. Surely there has never been a more awe-inspiring sports prototype than the Porsche 917.

Built around a multi-tubular aluminum space frame, titanium and magnesium alloys were used extensively for the lightest weight possible. Run by a team headed by John Wyer and sponsored by Gulf, 917 coupes won the World Championship in 1970 and 1971, easily beating Ferrari’s 5-liter Sports prototypes, the 512S and 512M.

After the 917 Coupes were outlawed via a rules change, they found a home in the Can-Am series, first as a normally aspirated “PA” Spyder and later as turbocharged 880hp bombshells. Swiss ace Jo Siffert had run a normally aspirated 917 in the Can-Am in 1969, but realized that the car lacked power when matched against the all-conquering big-block Chevrolet- engined McLarens. The 917/10 was the result of the Porsche factory seeking more power from its “Typ 912” flat twelve engine. Although they tried a flat 16 engine of 7.1 liters producing 880 hp, turbocharging the smaller engine offered the potential for even greater power.

The car shown here is the 917/10 that Jo Siffert tested at Hockenheim on July 8, 1971 under the watchful eyes of Porsche Motorsports boss Ferdinand Piech and Development Engineer Helmuth Bott. Jo Siffert was given the car to use as long as he bore the costs of campaigning it in the USA.

The car was delivered to Watkins Glen for the Can-Am race of 25 July, finished in brilliant Day-Glo orange and STP stickers to recognize Siffert’s new sponsor. With little practice, Siffert finished third. He went on to bring the car home in the top five in the remaining Can-Am races, including second at Mid-Ohio and Road Atlanta, fourth in Edmonton, and fifth places at Donnybrook and Laguna Seca. Siffert discovered the 5.0 liter 917/10 Spyder was the equal of the field except for the works McLarens.

Sadly, Siffert was killed in October 1971 in a non-Championship GP race at Brands Hatch. The 917 was returned to Porsche and became the test bed for developments of the turbocharged flat-12. Under the direction of Klaus Bischof, factory race mechanics brought the car up to the latest specification with numerous changes in the interests of better driveability and even more speed.

Willi Kauhsen purchased the modified 917 from Porsche in the spring of 1972 for $62,500. His place was to race in the Interseries, the European equivalent of Can-Am. Kauhsen obtained sponsorship from Bosch and with the car now painted bright yellow, started the season at the Nürburgring and was blindly quick, finishing in second place. He won the next race at Imola in Italy, but retired at Silverstone. He finished second in each of the next four races. The only other car to stay ahead of him was the 917/10 of the 1971 Interseries Champion, Leo Kinnunen.

At the final race of the season in September back at the Nürburgring, Kauhsen crashed. He put the damaged car into storage for twenty-six years. Finally, a meticulous restoration was undertaken by a team of former race mechanics from the Weissach works with assistance from Gustaf Nietsche and Claus Bischof, head of the Porsche museum. The rebuild returned the car to the specification it had run with Jo Siffert in the 1971 Can-Am championship.

Since completion, the car has had but two outings, the Goodwood Festival of Speed and the Oldtimer Grand Prix in 1999. In a recent conversation with the former shop manager for Vasek Polak, Carl Thompson confirmed that the unblown cars are some of the best handling Porsche cars ever built, enormous fun to drive, and highly responsive to the throttle.

This is in effect a two-owner from new 917/10 that has been in its present ownership for thirty years. The car comes with a spares package that includes suspension struts, joints and forks, assorted gear sets, brake calipers, four wheels, two windshields and other items. A comprehensive history file is included.

SCM Analysis

Detailing

This rare 917/10 race car sold for $660,000 at Christie’s in Pebble Beach, on August 20, 2000, a market-correct price. 917s reflect the period when Porsche was still managed by family members and won its first overall World Championship of Makes in 1970. Prior to this, Porsche was a winner only in the small-bore classes, leaving Ferrari and others to collect overall victories.

This period produced some of the most dramatic race cars ever seen, and in many ways, these brutally fast cars were well ahead of their time. Aspects of the body design can be seen in the open sports cars raced at Le Mans nearly thirty years later. In a 1997 poll of motor-racing experts conducted by Motor Sport magazine, the Porsche 917 was declared the greatest racing sports car of all time.

How fast was this car? Clocking a 0-100 kph (about 62 mph) time of 2.7 seconds, it reaches a top speed of about 220 mph. The beauty of this car though, apart from its history and condition, is that it remains able to be driven by gentlemen racers of reasonable skill. This is in contrast to the later turbocharged cars, which are difficult to pilot as the turbo lag can be counted in seconds, both on and off the power.

Some may argue that the minimalist body shape is largely without style, with its short overhangs and slab sides. However, this body was a reinterpretation of the mid-1950s Porsche 550 Spyders, intended to create the simplest, lightest coverings for wheels and chassis. The 550 had a flimsy alloy body over a mid-engined tubular frame, while the 917 had a flimsy fiberglass body over a mid-engined tubular frame. But unlike the modest power of the 550, the 917 matched the flyweight body and chassis with the prodigious horsepower allowed by the rules.

The engine, essentially two flat sixes mounted back to back, shares no crankcase parts with any standard-issue 911. Although called the “Typ 912,” the 917 flat 12 couldn’t be more different from the 4-cylinder 912 roadcar engine, whose final engine designation is “Typ 616/40.”

Open 917/10 cars are something of a bargain when compared with the earlier coupes, which can cost two to three times as much. This car, with its no-mystery history and carefully documented rebuild, should appreciate at the head of the sports-racing market.—Jim Schrager

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