Audi 4.2-liter V8 FSI, Обучение по обслуживанию

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Exhaust System
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Exhaust System
During the development of the exhaust system, special emphasis was placed on optimizing flow resistance.
Audi Q7
Each cylinder bank has its own exhaust pipe. The air-gap
insulated exhaust manifolds are flanged onto the cylinder
heads.
They offer the advantage of low heat loss in the exhaust
gas. As a result of this, the primary catalytic converters
are able to heat up quickly.
The primary catalytic converters are ceramic type
catalytic converters. The O
2
sensors are connected to
them. The O
2
sensor upstream of the catalytic converter
is a broadband sensor.
A nonlinear sensor is located downstream of the catalytic
converter. The main catalytic converters in the underbody
area are also ceramic catalytic converters. The exhaust
pipes of the individual cylinder banks discharge into
a front silencer. Both the front and rear silencers are
absorption-type silencers. A crossover function in the
silencer ensures higher engine power output and torque.
The front and rear silencers are connected by separate
pipes. Again, the rear silencer is a common component
of both exhaust pipes. On the inside of the rear silencer,
however, the left and right exhaust pipes are clearly
separated.
Audi RS4
To enhance the sporty character of the RS4 engine, a fan-
type manifold is used in the RS4.
Good separation of the exhaust pulses is ensured by
keeping the individual exhaust pipes apart until they
merge into one. These fan-type manifolds are also
attached by means of a clamping flange system.
The primary and main catalytic converters are metal-type
catalytic converters. Their advantage is that they have a
lower flow resistance than ceramic catalytic converters,
which is good for engine performance.
The front silencer for each of the exhaust pipes is housed
in a common casing. However, the exhaust pipes are kept
separate. The front and rear silencers are absorption-type
silencers. They are notable for their low flow resistance.
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Audi Q7 Exhaust System
Exhaust Manifold
Primary Catalytic Converter
Decoupling Element
Main Catalytic Converter
Front Silencer
Rear Silencer
Oxygen (O2) Sensors