Cooling

Cooling







In order to take into account the higher cooling requirement of the engine oil on the new 911 Turbo, the waste heat is now dissipated into the coolant by way of two oil-water heat exchangers instead of one (996 Turbo). As a result, it was possible to increase the cooling performance by more than 15 %.

The second heat exchanger is located in the return line to the oil tank. This arrangement reduces any possibility of increased pressure increased resistance from the second heat exchanger, and ensures that the engine is adequately supplied with oil. In addition, heat transfer to the coolant and therefore also the cooling performance is increased since the temperature in the return line is higher than in the oil pressure line. Routing of the coolant lines ensures optimum distribution to the heat exchangers and other fluid-cooled components.

The heat from the coolant is dissipated to the environment by way of side radiator modules located on the left and right in front of the front wheels, as well as a center radiator in the front end. During aerodynamic development of the front end, particular attention was paid to increasing the cooling air throughput in order to permit dissipation of the additional heat produced by the increased engine power while keeping the radiator dimensions unchanged.

For the first time the bearing housings of the turbochargers on the new 911 Turbo are cooled with coolant. This takes place by way of a separate electrically operated pump, which is mounted on the engine behind the secondary air pump (see illustration below, red arrow "P"). This increases coolant throughput at low engine speeds in accordance with the cooling requirement, and also permits efficient cooling of the highly loaded turbochargers when the engine is stopped after the vehicle has been driven with high power demands.