Three-quarter aerial view of a 1973, Porsche 917/30 Spyder on Display at the 2016 Silverstone Classic
Contributor:John Gaffen 2 / Alamy Stock Photo
File size:60.2 MB (2.9 MB Compressed download)
Releases:Model - no | Property - noDo I need a release?
Dimensions:5616 x 3744 px | 47.5 x 31.7 cm | 18.7 x 12.5 inches | 300dpi
Date taken:30 July 2016
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 test track top speed of up to 240 mph (390 km/h). The highest official speed ever clocked for a 917 at Le Mans is 362 km/h or 224.4 mph. As the new rules for the 3-litre prototypes were not favourable to their existing low-weight, low-power Porsche 908, Porsche decided against developing a new high power engine that could keep up with the F1-based engine designs of the competition — at least in naturally aspirated form. In 1976 they would return to sport-prototype racing with the turbocharged Porsche 936 race cars after the engines were tested in Porsche 911 versions. After their successes with the 917 mainly in Europe, Porsche instead decided to focus on the North American markets and the Can-Am Challenge. For that series, larger and more powerful engines were needed. Although a 16-cylinder engine with about 750 hp (560 kW) was tested, a turbocharged 12-cylinder engine with comparable power output was ultimately used. The 917 chassis also had to be lengthened to accept the longer 16-cylinder engine, and drivers complained that this longer chassis did not handle as well. 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. This broke the five-year stranglehold McLaren had on the series. The further evolution of the 917, the 917/30 with revised aerodynamics, a longer wheelbase and an even stronger 5.4-litre engine with up to 1, 580 horsepower (1, 180 kW) won the 1973 edition winning all races but two when Charlie Kemp won the Mosport race and George Follmer won Road Atlanta and Mark Donohue won the rest.