Audi 4.2-liter V8 FSI, Обучение по обслуживанию

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Exhaust System
29
Audi RS4 Exhaust Flap Control
A further difference is the layout; one exhaust flap is
located downstream of each of the rear silencers. The
exhaust flaps are fitted to give the engine a sporty sound.
Low-frequency droning noise at low engine RPM is
prevented. At high engine RPM and high exhaust gas flow
rates, flow noise and exhaust back pressure are reduced
by opening the additional cross-section.
The exhaust gas flaps are closed at idle, low engine load
and at low engine RPM.
Function
The exhaust flaps are switched by a vacuum actuator.
Both vacuum units are switched by an electrically
activated solenoid valve. The exhaust flaps are switched
according to a characteristic map.
The factors of engine load, engine RPM, gear selected
and the shift signal from the Sport button are used to
plot the characteristic map.
For example, the exhaust flaps are opened at idle when
the Sport button is pressed.
377_046
377_060
Audi RS4 Exhaust System
Fan-type Exhaust Manifold,
4 in 2 in 1
Primary Catalytic Converter
Decoupling Element
Main Catalytic Converter
Front Silencer
Oxygen (O2) Sensors
Rear Silencer
Exhaust Actuator Flap
Vacuum Control
Actuator