1977: Charge-air cooling

One of the secrets to the success of the 911 series is its constant and systematic enhancement. Each year, many small details on the 911 have been improved, making it closer and closer to Ferry Porsche’s ideal image of the perfect sports car. This philosophy was also applied to the 911 Turbo. The main features of the 911 Turbo, reworked in 1977, were an increased displacement of 3.3 litres and a charge-air cooler positioned underneath the rear spoiler. Derived from the field of motor racing, it was a world first in a series production car. The charge-air cooler reduces the intake air temperature by up to 100 degrees Celsius, thus enabling the engine to achieve higher output and torque in all engine speed ranges – cooler gases are denser and therefore charge the engine more effectively. The result was a stable 300 hp at 5,500 rpm and a maximum torque of 412 Newton metres. Furthermore, charge-air cooling also reduces the thermal load on the engine. The exhaust gas temperatures fall, as do the emissions, and fuel consumption is reduced. Another advantage is the improvement in antiknock properties – excess temperatures causing the mixture to self-ignite is virtually ruled out.