Intake Air Side, Air Routing

Intake Air Side, Air Routing

General

The intake systems in all new Cayenne models have been redesigned for direct fuel injection (DFI) in order to achieve a high torque curve. The air cleaner elements must be changed every 72,000 miles (120,000 km) or after 4 years according to the Technical Data.

NOTE: Air filter replacement intervals have changed for M.Y. 2008 when compared to the 2003-2006 Cayenne models.


Cayenne Turbo Intake System







The illustration shows the intake system, from the air intakes behind the left and right headlights, the air filter housings, the two pipe mass air flow sensors, the turbocharger and the charge air cooler to the electronic throttle. A sensor in front of the electronic throttle records the boost pressure and air temperature.

Turbo Pressure System







The pressure system in the new Cayenne Turbo is manufactured in a plastic shell design like the variable intake system in the Cayenne S. The pressure system comprises three shell elements, where the bottom shell is identical to the variable intake system. It is also made of plastic, for example, to ensure a low weight. Unlike the V8 naturally aspirated engine, the switching flaps are not required since the charge effect is produced by the two turbochargers. As a result, the low-loss short intake manifold lengths are effective for the entire map. The weight of the pressure system in the 4.8 l turbo engine compared to the 4.5 l engine is reduced by approx. 3.3 lbs. (1.5 kg).

Positive Crankcase Ventilation - Cayenne Turbo

With the enhanced positive crankcase ventilation system, it was possible to reduce the amount of fuel produced during combustion and entering the engine oil through the combustion gases, which pass the piston rings and penetrate the crankcase (blow-by gases). The enhanced aeration and ventilation system (Positive Crankcase Ventilation - PCV) now ventilates the crankcase with a steady stream of fresh air, which accelerates the evaporation of fuel that is carried in. For this purpose, fresh air is removed between the charge air cooler and throttle valve and is delivered to the crank chamber via a line.

The pressure that exists at any time between the removal position and the crankcase causes a steady flow of fresh air through the crankcase in all map points. To ensure sufficient vacuum in the crankcase in all map points, the vacuum in the intake manifold is used in the partial load ranges. A pressure regulating valve regulates this vacuum until the required value is reached. In the operating range with accumulated boost pressure (full load) in which there is no vacuum in the intake manifold, the vacuum upstream of the compressor is used.

To prevent the PCV system from freezing during the winter, the blow-by gases on both naturally aspirated and turbo engines are supplied to the combustion air through a heated adapter.