Turbocharging, function

P09.00-2092-05

1 Turbocharger

2 Charge air cooler

3 Exhaust gas recirculation actuator with mixed air housing

4 Charge air manifold

5 Air filter housing

A Suctioned in fresh air

B Hot charge air

C Cooled charge air

General

The cylinder charging efficiency is improved as a result of charging. The engine torque and power output are boosted as a result.

Function

The fresh air is suctioned in via the air filter housing and cleaned by the air filter installed in the air filter housing. The fresh air passes via the air line to the turbocharger. The turbocharger driven by the flow energy of exhaust gases suctions in the fresh air coming in from the air filter housing. The air is compacted by the high rpm of the compressor impeller and the resulting high volume flow and passed on to the charge air cooler.

The charge air cooler cools the charge air warmed by the compression and leads it to the exhaust gas recirculation actuator with mixed air housing. It is then led from there via the charge air manifold to the individual intake ports.

Boost pressure control

The boost pressure generated by the turbocharger operates via a connector hose on the membrane of the vacuum cell. At a too high boost pressure the spring force of the vacuum cell is overcome and the control rod connected to the vacuum cell opens the boost pressure control flap installed in the turbocharger.

Through this a part of the exhaust gases is led through the bypass opening on the turbine wheel into the exhaust system and the boost pressure drops. As soon as the boost pressure is less than the spring force of the vacuum cell the boost pressure control flap is closed via the control rod.

 Acceleration of the turbine wheel requires a minimum amount of exhaust which is only available from an engine speed of about 1800 rpm. Below this rpm the turbocharger remains ineffective.