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
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.
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.
934 competed in the 1976 Trans-Am Championship against Corvettes and Camaros. The season was won by George Follmer driving a 934.
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).
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.
From mid-season 1977, many 934/5 were even fitted with boxed rear fenders from 935.
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