Porsche 934 (911 Turbo RSR 3.0, 1976-1977)

Premiere: February 1, 1976 Daytona 24 hours

Engine: 3.0 flat-6 turbocharged with air-to-water intercoolers, 357 kW
Gearbox: 4-speed

The 911 Turbo RSR 3.0 is a racing car homologated thanks to the G-model 911 Turbo 3.0 aka 930. Made for the Group 4 racing, the car was internally called as 934. With coefficient of 1.4 or +40% for turbocharged cars, the 3-litre turbo engine was considered to put out the power similar to a 4.2-litre naturally aspirated engine. Considering the 911 Carrera RSR 3.0 had 246 kW and the 911 Turbo RSR 3.0 has 357 kW, the difference is 45%. Naturally, with the turbocharged cars the power depended on how much you dared to raise the boost pressure, so 357 kW was the starting point. For comparison, the street legal 911 Turbo had 191 kW in Europe and the Turbo Carrera 180 kW in USA. So, the Turbo RSR had twice the power of the Turbo Carrera.

The minimum weight set for the Turbo RSR by the rules was high, so the car retained power windows and full door panels like in the 911 Turbo. The dashboard is a simpler spartan piece, though. In the centre of the dash is a prominently placed turbo boost pressure regulator knob. The car was naturally fitted with the safety cage and a bucket seat for the driver. The car also had a fire extinguishing system with lines distributed throughout the cockpit. In order to meet the minimum weight, even ballast had to be added. It was the heaviest racing car Porsche had built.

Porsche 934 — Oil cooler in the centre and charge air water coolers on the sides behind the huge front spoiler© Porsche

The space under the front lid is fully occupied by fuel and oil tanks. The engine room is completely different compared to the 911 Turbo. There are the water-cooled intercoolers on top of the engine and the engine fan is also mounted horizontally on top of the engine. The exhaust gases exit straight through the turbocharger and the wastegate, there is no muffler. There were a few sets of gear ratios available. For example, one set gave the following speeds in gear: 1st 70 mph / 113 km/h and 2nd 99 mph / 159 km/h! Redline was set at 7000 rpm.

Porsche 934 cockpit — The line of the fire extinguisher system and the turbo boost knob can be seen© Porsche

Porsche 934 front wheel arch — On a street car you would see the fuel tank flap on the fender, but not on 934 © Porsche

934 competed in the 1976 Trans-Am Championship against Corvettes and Camaros. The season was won by George Follmer driving a 934.

Porsche 934 George Follmer — 1976 September 5, Trans-Am Trois-Rivières winner George Follmer © Corel Photos

Porsche 934 Al Holbert — 1976 September 5, Trans-Am Trois-Rivières second place Al Holbert © Corel Photos

Porsche 911 Turbo Carrera, Turbo RSR (934), 935 — 911 Turbo Carrera (as it was initially marketed in USA), 911 Turbo RSR (934) and 935 © Corel Photos

Porsche 935 and 934 — 935 and 934 © Corel Photos

In Europe, most of the cars competing in the 1976 European GT Championship were 934. The championship was won by Toine Hezemans (100 points), followed by Helmut Kelleners and Tim Schenken (both 57 points).

1977 Porsche ad, 934, 911, 911 Turbo — 1976 advertising of 1977 model year cars © Porsche

In order to convert Group 4 934 into a Group 5 car, it was fitted with wider wheels, wider rear wheel arches and the wing from the 935. These 934/5 cars were first seen at the 1976 Nürburgring 1000 km race, where Toine Hezemans/Tim Schenken scored second. By 1977, most of the 934 were modified to 934/5.

Porsche 934/5 — 934/5 can be distinguished by the wider rear wheel arches and the 935 rear wing © Porsche

1977 Trans-Am poster with Porsche 934/5 — © Porsche

From mid-season 1977, many 934/5 were even fitted with boxed rear fenders from 935.

Continue to Porsche motorsport moments

Anniversaries: Oct, 29 – 81st birthday of Hans-Peter Porsche (1940); Nov, 15 – 46th birthday of the 924 (1975); Nov, 19 – 13th birthday of the Boxster 987.2 (2008); Nov, 19 – 13th birthday of the Cayman 987.2 (2008); Nov, 26 – 58th birthday of the 904 (1963)