History of the 1973 - 1977 Porsche 911
Porsche increased the size of the 911 engine for 1974 to 2,687cc and ceased making the T and E models. The new cars were introduced at the Frankfurt Show in September 1973, and choices were the 150 bhp standard car, the 175 bhp S, and the 210 bhp Carrera. Beautifully integrated bumpers were a response to US safety regulations, and were constructed of aluminium, with alloy bars that held them away from the body and were designed to crush at 5 mph. Cars built for the British market did even better, with standard hydraulic pistons that were designed to compress and spring back. These were optional in other markets.
All three models used the Bosch K-jetronic continuous feed fuel injection. The 911 continued to use the air box as the middle plenum for the injection, and woe betide any owner who pumped the accelerator before hitting the starter. The extra fuel would detonate in the air box, blowing the system apart and preventing the car from running. A hand throttle was supplied to set a fast idle from cold, and this would continue to 1976, when it was discontinued.
All 1974 911s got a front spoiler, redesigned wheels, high-back front seats, a 21.4-gallon fuel tank, up from 16.4 gallons, and high-pressure headlight washers. The high-performance racer was the Carrera RSR, which boasted 330 bhp from its 2,993cc engine. Only 49 of the 109 RSRs built ever went racing, while the others were driven excitingly on European roads. Porsche pared 911 models to just the S and the Carrera in 1975, while introducing the extremely fast and unforgiving 911/930 Turbo, with 260 bhp and 155 mph.
The years 1976 and 1977 saw a few key changes, the first being the introduction of zinc plating to the 911's body and chassis, accompanied by a six-year anti-rust warranty. As usual luxury items filtered down the line and a 1976 911S has most of the equipment available on the Carrera in 1974. Minor changes to dash vents and door locks followed in 1977 and the magnesium crankcase was finally discontinued. The 911C of 1978 would define this body series and be built with limited changes until 1983.
Interested. Users who cast an eye towards drier American climates should be aware that there some serious differences among cars built for the US market. Specifically, many cars utilised thermal reactors in an effort pass emissions. The reactors were designed to burn any surplus fuel by dint of raising temperatures, though those high temperatures ultimately damaged the engine. The only solution is to fit an additional front oil cooler to mitigate the problem. American-bound 911s were also less powerful due to emissions equipment, resulting in outputs of 143 bhp, 168 bhp, and 174 bhp. There is a particularly steep difference in value between US and European-spec Carreras.