DaimlerChrysler SPRINTER2006 Service Manual page 124

11 - 4 EXHAUST SYSTEM
• Reduction in exhaust emissions as a result of an
improvement in the air supply of the engine.
• Increased power output as a result of the higher
charge pressure combined with a reduced exhaust
backpressure and thus improved charge cycle.
OPERATION
The exhaust gases of the engine are directed
through the exhaust manifold into the turbine hous-
ing onto the turbine wheel (Fig. 2). The flow energy
of the exhaust gases cause the turbine wheel to
rotate. Consequently, the compressor wheel, which is
connected through the turbine shaft with the turbine
wheel, is driven at the same speed. The fresh air
inducted by the compressor wheel is compressed and
passed to the engine (Fig. 2).
The charge pressure is controlled by varying the
position of the guide vanes (Fig. 2). The guide stud of
the control linkage of the boost pressure actuator
turns the adjusting ring in the turbine housing (Fig.
2). As a result, all the guide vanes whose guide studs
likewise mesh into the adjusting ring, are also
turned (Fig. 2).
At low speeds, the flow cross-section is reduced by
closing the guide vanes (Fig. 2). Consequently the
speed at which the exhaust gas impacts on the tur-
bine wheel is increased, as a result of which the
speed of the turbocharger and thus the charge pres-
sure rises.
At high engine speeds the guide vanes are increas-
ingly opened and the flow cross-section is thus
enlarged, as a result of which the speed of the turbo-
charger reduces and the charge pressure drops.
Fig. 2 TURBOCHARGER COMPONENTS
1 - COMPRESSOR HOUSING
2 - GUIDE VANE
3 - GUIDE STUD OF GUIDE VANE
4 - GUIDE STUD OF CONTROL LINKAGE
5 - CONTROL LINKAGE
6 - ADJUSTING RING
7 - TURBINE HOUSING
8 - BOOST PRESSURE CONTROL UNIT
1A - EXHAUST GASES TO TURBINE WHEEL
2A - TURBO INLET (FRESH AIR)
3A - TURBO OUTLET (COMPRESSED AIR)
4A - EXHAUST OUTLET
CHARGE AIR COOLER AND
PLUMBING
DESCRIPTION
The charge air system consists of the charge air
cooler and charge air cooler piping.
The charge air cooler is a heat exchanger that uses
air flow from vehicle motion to dissipate heat from
the intake air. As the turbocharger increases air
pressure, the air temperature increases. Lowering
the intake air temperature increases engine effi-
ciency and power.
VA