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. It was 25 mph faster down the straights than the 917K and the Ferrari 512Ss. Two were entered in the 1970 Le Mans race, one by Porsche Salzburg and the other by Martini Racing. The Porsche Salzburg 917L was qualified in pole position by Elford, but retired with engine failure after 18 hours and the Martini 917L finished 2nd, five laps behind the winning Salzburg 917K of Hans Herrmann and Richard Attwood. 1971 917 16 Cylinder: In an effort to keep up with other more powerful cars in the Can-Am championship, a 6.6 litre, 750PS (551kW, 739 bhp) flat-16 engined prototype was developed. It was tested in the original 917PA chassis, with the wheelbase extended by 270mm to take the longer engine. Although more powerful than the flat-12, it was also 80 kg heavier. Porsche decided that turbocharging the flat-12 would be more profitable, and the flat-16 was shelved. 1971 917K: The 917K was further developed for the 1971 season, and the car had vertical fins and two airboxes on the tail section for better aerodynamics and cooling. The fins retained the airflow over the rear part of the bodywork, allowing the deck height to be reduced for a given level of downforce. As a result, the 'finned' 1971 917Ks were faster than the 1970 versions and proved just as successful, winning seven of the eleven WSC races. A version of this model with a lightweight magnesium chassis won the 1971 24 Hours of Le Mans. 1971 917LH: The 1971 model was a further development of the 1970 917L and was also made specifically to compete in only one race: the 1971 24 Hours 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. Two were run by JW Automotive and one by the Martini International team. Although Jackie Oliver qualified one of the JW 917LHs on pole position, none of the three cars finished the race. 1971 917 Interserie Spyder: Three Porsche 917 Spyders were built for use in the German Interserie championship, rebuilt from 917s that had been crashed or otherwise written off. These cars were very successful, winning