1969 917: The original Porsche 917 was first run at the Le Mans Test in March 1969 and right from the start showed considerable handling problems due to aerodynamic lift.

The Porsche technical team turned out ready to do some serious panel work on the coupé and in order to make a comparison, brought along the Can-Am 917PA Spyder.

Such was the improvement in the stability of the car at high speed, the 917K became the standard configuration for all races except Le Mans, the Nürburgring 1000 km and the Targa Florio.

The smaller, more nimble and generally better suited 908/03s were used for those races, but privateers used the 917K at the Nürburgring 1000 km, and Vic Elford drove a lap of the 44-mile Targa Florio course in the 917K at Ferdinand Piëch's request.

Le Mans in 1970 was almost entirely made up of long straights and this version was designed to maximise the speed capability resulting from the increased power developed by the flat-12 engine over the previous Porsche types.

Nevertheless, factory driver Vic Elford had found the car's ultimate speed an advantage enough over its still questionable handling in the braking and cornering sections of Le Mans.

The car was also more stable than its 1970 predecessor because of a revised suspension set up and new bodywork with partially enclosed rear wheel covers and a redesigned front section.

It was made as an intermediate car to combine the low drag of the Langheck and the stability of the Kurz, and was also a test-bed for future Can-Am parts and aerodynamic low-drag concepts.

It was finally determined that the "long tail" body was generating significant lift on the straights, as the 917 was 30 km/h (19 mph) faster than anything previously built for Le Mans [citation needed].

As it was necessary to promote the car in order to sell the surplus ones, Porsche asked BMW for the services of their factory drivers Hubert Hahne and Dieter Quester.

They practised, but Munich declined permission to have them race, so Englishman David Piper and Australian Frank Gardner were hired on short terms.

They drove the 917 to an eighth-place finish behind a Ford and an Alfa, while the factory's armada of six 908/02 spyders scored a 1-2-3-4-5 win after the only serious competition, a sole Ferrari 312P, failed.

At the end, Hans Herrmann's 908 remained as the only Porsche that could challenge for the win, but Jacky Ickx's more powerful Ford won once again, by a mere 120 metres (390 ft).

The Österreichring was the circuit where the car had won its only race at that time, Wyer's chief engineer John Horsman noticed that the bodywork had a pattern of dead gnats dashed against it, revealing the airflow.

Vic Elford drove a 917 during practice for the 1970 Targa Florio and it proved to be so physically demanding and difficult to drive around the circuit that he had to be lifted out of the car, although he set the 5th fastest time[citation needed].

At the end it was the red and white #23 917K of Porsche Salzburg, with the standard 4.5-litre engine, carefully driven by Stuttgart's own Hans Herrmann and Englishman Richard Attwood through the pouring rain, that finally scored the first overall win at Le Mans, in a wet race that saw only 7 ranked finishers.

The season began with the JW Automotive team scoring a 1-2 finish at the Buenos Aires 1000km, Jo Siffert and Derek Bell leading Pedro Rodriguez and Jackie Oliver home.

At Brands Hatch, a large grid on the twisting, damp track suited the Italian cars and Porsche finished third behind the Alfa Romeo of Andrea de Adamich and Henri Pescarolo and the Ferrari of Jackie Ickx and Clay Regazzoni.

The high-speed circuits at the Monza 1000km and Spa 1000km played to the 917's strengths and the JW-Gulf cars finished 1-2 in both races, Pedro Rodriguez and Jackie Oliver being the winners in both events.

Throughout the season Porsche continued to develop the 917, introducing new versions of the short and long-tailed bodywork, and trying out a magnesium chassis, with which they would win the 1971 24 Hours of Le Mans.

The 917/20 had done well in the early-season Le Mans Test, but uncomplimentary remarks about its size and shape resulted in it being painted in pink for the 24 hour race, complete with names of cuts of meat written across it in German like a butcher's diagram.

Also at Le Mans the revised Langhecks, now cured of their earlier vices, all failed to finish, although Pedro Rodriguez set a fastest qualifying lap which, partly due to circuit changes, still stands today.

The winning car was the Martini Racing 917K of Helmut Marko and Gijs van Lennep, equipped with a magnesium frame, which set an overall distance record that stood until 2010.

However, the Alfa Romeo Tipo 33 of Andrea de Adamich and Ronnie Peterson beat the JW Porsches to the flag by a margin of two laps.

JW Automotive took a car to the non-championship Barcelona 1000km and the 1000 km of Paris, Derek Bell and Gijs van Lennep winning the latter event.

[citation needed] The turbocharged 850 hp (630 kW) 917/10K entered by Penske Racing won the 1972 series with George Follmer, after a testing accident sidelined primary driver Mark Donohue.

[citation needed] The 917's domination, the oil crisis, and fiery tragedies like Roger Williamson's in Zandvoort pushed the SCCA to introduce a 3 miles per US gallon (78 L/100 km) maximum fuel consumption rule for 1974.

The car raced at Le Mans qualifying in the top 10 but retired after seven hours after a collision with a back marker led to a loss of oil and withdrawal.

On 9 August 1975, Porsche and Penske would give the Can-Am car its final send off in style, when they took their 917/30 to Talladega to break the FIA speed record on a closed circuit.

The Gulf Oil liveried 917 'Kurzhecks' are also prominently featured in the Steve McQueen film Le Mans competing against Ferrari's 512 Coda Lunga.