The RSR was a milestone moment for Porsche. It was the first turbocharged racing 911, one that took part in the FIA’s Group 5 category for the 1974 World Championship for Makes and came 2nd overall at the 24 Hours of Le Mans. Just look at this thing and it is clear that Porsche was nuts (which we totally love).
While Porsche had success early on with small and powerful engines, is was really the RSR that showed just how successful a small-capacity turbocharged engine could be in a standard race car. The 917/30’s success drove Porsche to turbocharge more stuff and Porsche had decided to launch the new 911 Turbo in 1975/ Porsche wanted to prove the abilities of a turbocharged 911 in competition. To do so, they created the Porsche 911 Carrera RSR Turbo 2.1. Thanks to the FIAs requirements for a smaller than 3 liter engine for Group 5 cars, Porsche decided on a 2.14 liter flat-six and then added to monster KKK turbochargers to it.
Thats not all either, because this motor had magnesium crankcase, polished-titanium connecting rods, large-capacity oil pumps, a twin-plug ignition, Bosch mechanical fuel injection, and sodium-cooled intake valves (space aged stuff at the time). The result was 500 hp at 7,600 rpm and 405 lb-ft of torque at 5,400 rpm (in 1974). The RSR would wear fiberglass fenders, doors, front and rear valances, and front and rear decklids — all engineered for weight-savings — and tubular framing supported the engine and suspension.
Porsche extensively tested the car at the Le Mans trails and found it was 11 seconds faster than a 3.0 RSR. Four cars were made for the 1974 season and they debuted at the Monza 1000km.
Only four RSR Turbos were ever built (“R5,” “R9,” “R12,” and “R13″) and they all wore the now famous Martini livery. Unfortunately, the 2.14s had to race in the prototype class along with the Matra-Simca MS670C, Gulf Mirage GR7 and Alfa Romeo 33TT12. Despite the tough company, the Martini & Rossi-livered cars managed second place finishes at the Watkins Glen 6 Hours and the 24 Hours of Le Mans.