24h Le Mans
Forty years ago, the Porsche 936 became the first prototype with a turbocharged engine to win the 24 Hours of Le Mans. The 936’s design heritage draws on a number of the marque’s emblematic racing cars, from the 911 to the 917. In this second episode, we go back to 1974 to take a look at a very special version of the 911.
The two CanAm Challenge Cup wins in 1972 and 1973 with the 917/10 and 917/30, coupled with the 1973 oil crisis, encouraged Porsche engineers to step up their development of turbocharged engine technology. And what better testing ground than the 24 Hours of Le Mans?
The car selected for the purpose was none other than the Carrera RS, a more powerful and lighter version of the ever-resilient 911 that appeared in 1972. Its 2.1-litre flat-6 engine was equipped with a turbocharger, taking it from 300 to over 460 hp. The Carrera was also slimmed down considerably and the necessary alterations were made to transmit this massive amount of extra power to the asphalt. These changes included an impressive rear section with wider fenders to accommodate the 17-inch wheels, and a huge wing beneath which the workings of the engine were proudly displayed. Out on the track this very special 911 backfired spectacularly, accentuating its bestial roar.
Two examples of this Carrera RSR Turbo were entered as experimental cars in the 24 Hours of Le Mans in 1974 – #21 driven by Manfred Schurti and Helmut Koinigg, and #22 by Herbert Müller and Gijs van Lennep. Although engine failure put paid to the chances of #21 in the eighth hour of the race, its sister car emerged from the night in second position, behind the Matra of defending Le Mans champions Gérard Larrousse and Henri Pescarolo.
At one point, it looked like the Carrera RSR Turbo might even clinch victory when Larrousse and Pescarolo encountered gearbox trouble on the Sunday morning before Müller and Van Lennep were affected by the same problem shortly afterwards. At the chequered flag, the gap between the winning Matra and the Carrera RSR Turbo was twenty kilometres – just a lap and a half!
The Porsche engineers were now convinced that turbochargers were indeed the solution of the future. Two years later, the engine of the Carrera RSR Turbo was mounted in a chassis inspired by the bodywork of the 1973 CanAm-winning 917/30. This car was the Porsche 936. You can read all about the adventures of the 936 at Le Mans... in the next episode!
Previous episode in the saga: Porsche 936, the making of a prototype (1/4) – Porsche 917, 1971–1973.
Photo: The runner-up of the 1974 24 Hours, the Porsche Carrera RSR Turbo was fitted with engine of the forthcoming 936.
