Legendary Porsche 917 celebrates 40th birthday

The Porsche 917 subsequently became a legend as one of the fastest and most successful racing cars of all time, and its 40th anniversary is celebrated this year with a special exhibit at the new Porsche Museum in Stuttgart and a 917 display at the 2009 Goodwood Festival of Speed (July 3 - 5).

Porsche fired the starting shot for Project 917 in June 1968, after the international motor sports authority announced a class of 'homologated sports cars' with up to five litres engine capacity and a minimum weight of 800kg. Under the supervision of Ferdinand Piech, the stipulated 25 units of the new racing car model were completed by April 1969 so that the 917 could begin its racing career in the same year. After it initially dropped out of its first three races due to technical problems, the 917 success story began in August 1969 with victory at a 1,000-kilometre race at the Osterreichring driven by Jo Siffert and Kurt Ahrens.

The engine configuration of the 917 was just as unusual as the different body styles the car was presented in. Behind the driver's seat lay an air-cooled, twelve-cylinder engine with horizontal cylinders, whose crankshaft designated it as a 180-degree V engine. The 520 hp engine had an initial cubic capacity of 4.5-litres. The tubular frame was made of aluminium, the car body out of glass fibre reinforced synthetics.

Porsche engineers developed different body styles to best meet the different demands of different race track configurations. The so-called short-tail 'Kurz' model was designed for heavily twisting circuits in which a high tyre contact pressure was necessary for fast cornering. The long-tail 'Langheck' model was designed for fast race tracks and an ultimate high top speed. These were followed by the open 917 Spyders, which were used in the CanAm and Interseries races.

At the end of the 1970 race season, Porsche confirmed its superiority with the 917 and 908/03 models, winning the Racing Series World Championship [Markenweltmeisterschaft] in nine out of ten possible victories. This series of victories began at Daytona and continued at Brands Hatch, England, Monza, Italy, Spa, Belgium, on the Nürburgring race track in Germany, at the Targa Florio in Sicily, at Le Mans, France, Watkins Glen, United States of America, and the Osterreichring, Austria.

However, the season's high point was the long-desired overall win of the Le Mans 24-hour endurance race, a trophy that Hans Herrmann and Richard Attwood brought home to Zuffenhausen on June 14, 1970. Their 917 short-tail model painted in the Porsche Salzburg colours of red and white, with the start number 23, not only successfully defied its competitors but also the heavy rainfall.

As in the previous year, the 1971 season was dominated by the 917 model so that the Racing Series World Championship went to Porsche again with eight out of ten race victories. And once more, a Porsche 917 was victorious at the Le Mans 24-Hour race - this time with Gijs van Lennep and Dr Helmut Marko, who set a world record with an average speed of 222 km/h and 5,335 km driven, a record that still stands today. One special feature of their 917 short-tail model, visually characterised by its 'shark fin', was the tubular frame made of magnesium.

A 917 long-tail coupe model set a further record in 1971. On the Mulsanne straight, which is part of the route in the Le Mans 24-Hour race, the sports car with the start number 21 recorded the highest speed of 387 km/h. Another Le Mans race car achieved major recognition.

The Porsche 917/20 was a mix between the short-tail and the long-tail models and was notable for its broad proportions. Although the pink coloured racecar, nicknamed 'the Pig', dropped out halfway through the race, its unusual paint colour made it one of the most famous Porsche models ever.

When the European FIA regulation for the 'five-litre sports car' expired at the end of the 1971 season, Porsche decided to enter the Canadian American Challenge Cup (CanAm). In June 1972, the private Penske race team used the turbo-charged Porsche 917/10 Spyder for the first time. With performance of up to 1,000 hp, the Porsche Spyder dominated the race series and won for Porsche the CanAm championship with victories at Road Atlanta, Mid Ohio, Elkhart Lake, Laguna Seca and Riverside.

In the following year, the 1,200 hp 917/30 Spyder had its racing premiere. The superiority of the monster car driven by Mark Donohue was so obvious that the regulations of the CanAm series had to be changed in the end in order to exclude the 917/30 from competing further in the 1974 season.

However, as is typical for Porsche, the technologies for increasing performance developed for these races were successfully transferred to the sports cars for the road. That's how the 911 Turbo, with its side-exhaust turbocharger, began its career in 1974 and has been, since this time, a synonym for the performance capacity of the Porsche sports car.

To date, the reputation of the 917 is legendary. Indeed, 50 international motor sports experts from the famous British magazine 'Motor Sport' nominated the 917 as the 'greatest racing car in history'.

All in all, Porsche built 65 units of the 917; 44 sports cars as short-tail and long-tail coupes, two PA Spyders as well as 19 sports cars as CanAm and Interseries Spyders with up to 1,400 hp turbo engines. Seven of the most important 917 models - among them the Le Mans victory cars from 1970 and 1971 and the 917/30 Spyder - are currently exhibited in the new Porsche Museum in Stuttgart.