Porsche racing history

There are at least eleven variants of the 917. The original version had a removable long tail/medium tail with active rear wing flaps, but had considerable handling problems at high speed because of significant rear lift.

Porsche 917-K

The handling problems were investigated at a joint test at the Österreichring by the factory engineers and their new race team partners John Wyer Engineering and after exhaustive experimentation by both groups, a shorter, more upswept tail was found to give the car more aerodynamic stability at speed.

The Porsche 917 is a race car that gave Porsche its first overall wins at the 24 Hours of Le Mans in 1970 and 1971. Powered by the Type 912 flat-12 engine of 4.5, 4.9, or 5 litres, the 917/30 Can Am variant was capable of a 0-62 mph (100 km/h) time of 2.3 seconds, 0–124 mph (200 km/h) in 5.3 seconds, and a top speed of up to 240 mph (390 km/h).

Porsche 917K in the distinctive Gulf Oil livery.

The 917K, and the special Le Mans long-tail version (called the 917 Langheck, or 917L), dominated the 1970 and 1971 World Sportscar Championships.

The 908 originally was a closed coupe to provide low drag at fast tracks, but from 1969 on was mainly raced as the 908/2, a lighter open spyder. A more compact 908/3 was introduced in 1970 to complement the heavy Porsche 917 on twisty tracks that favored nimble cars.

The 1968 24 Hours of Le Mans were postponed from June to the end of September due to political unrest in France, setting the stage for a showdown between the 908s and the GT40s.

The Porsche 908 LH Long Tails were the fastest in qualifying and the early stages of the race, but it showed that Porsche had not taken advantage of the additional time to improve the 908. Troubles with the alternator caused delays and even disqualifications as the new Porsche team leaders had misinterpreted the repair rules. Once again, a V8-powered Ford won, and a 907 Long Tail came in second in front of the sole surviving standard 908.

For 1969, the Group 6 prototype rules were changed, and Porsche lowered the weight of the Porsche 908/02 Spyder by 100 kg (220 lb),
removing the roof and the long tails. Aluminium tube frames were used, with air pressure gauges to check them.

The 1969 24 Hours of Daytona were a disaster for Porsche, as all three 908/02 failed, and a Lola T70 won. At the 12 Hours of Sebring, a Ford GT40 defeated a trio of factory-entered 908/2s.