SsangYong Stavic / SsangYong Rodius (2005 year). Manual — part 103

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EXHAUST SYSTEM

DI ENG SM - 2004.9

TURBO CHARGER ASSEMBLY

The turbo charger is an air pump installed on the intake manifold. It enhances power and increases torque power of
engine to increase the fuel consumption rate. The engine without turbo charger cannot get as much power output as it
inducts air by the means of vacuum being generated from descending strokes of the piston. Therefore, by installing the
turbo charger on the intake manifold, it supplies great amounts of air to the cylinder increasing the volume efficiency
and, subsequently, enhances output power.

Also, as the engine’s power enhances, it increases the torque power and improves the fuel consumption rate. The
regular turbo charger operates by utilizing the pressure from the exhaust gas and the other, called Super Charger,
operates by utilizing power from the engine. When the turbo charger is installed, weight of the engine increases by 10
to 15 % whereas the output power increases by 35 to 45 %.

Operating Principle of Turbo Charger

The turbo charger has one shaft where at each ends are in-
stalled with two turbines having different angles to connect
one end of housing to the intake manifold and the other end to
the exhaust manifold. As the turbine, at exhaust end, is ro-
tated by exhaust gas pressure the impeller, at intake end,
gets rotated to send air around center of the impeller, being
circumferentially accelerated by the centrifugal force, into the
diffuser.

The air, which has been introduced to the diffuser having a
passage with big surface, transforms its speed energy into
the pressure energy while being supplied to the cylinder im-
proving the volume efficiency. Also, the exhaust efficiency
improves as the exhaust turbine rotates. The turbo charger is
often referred to as the exhaust turbine turbo charger.

Diffuser: With the meaning of spreading out it is a device that
transforms fluid’s speed energy into the pressure energy by
enlarging the fluid’s passage to slow down the flow.

Impeller

Turbine

Intercooler

Intake

Exhaust

Intercooler

coolant

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DI ENG SM - 2004.9

1. Turbine housing

2. Turbine wheel

3. Compressor housing

4. Compressor wheel

5. Center housing

6. Turbo charger booster pressure control valve

7. Control link

8. Bypass flap

Construction of Turbo Charger

The turbine wheel in turbo charger and compressor wheel are installed at each side of the shaft. It is comprised with the
shaft supporting center housing (supporting the compressor with two float journal bearings), the turbine side parts of
turbine wheel, shroud and turbine housing, and the compressor side parts of compressor wheel, back plate and com-
pressor housing.

• The turbine rotates turbine wheel by receiving exhaust gas energy from the engine.

• The compressor receives torque energy from the turbine and the compressor wheel inducts air to force it inside of

the cylinder.

A. Air inlet (from atmosphere)

B. Air flow

C. Exhaust gas inlet (from cylinder)

D. Exhaust gas outlet (to atmosphere)

E. Exhaust gas bypass passage

H. Oil supply opening

J. Oil return line

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EXHAUST SYSTEM

DI ENG SM - 2004.9

Impeller

The impeller is wings (wheel) installed on the intake end and
performs the role of pressurizing air into the cylinder.

The radial type has the impeller plate arranged in straight line
at the center of shaft and, compared to the backward type, is
being widely used as it is simple, easy to manufacture and
appropriate for high speed rotation. As the impeller rotates in
the housing with the diffuser installed in it, the air receives
centrifugal force to be accelerated in the direction of housing’s
outer circumference and flows into the diffuser.

As surface of the passage increases, air flown into the dif-
fuser transforms its speed energy into pressure energy and
flows into the intake manifold where the pressurized air is
supplied to cylinder each time the intake valve of cylinder opens
up. Therefore, the efficiency of compressor is determined by
the impeller and diffuser.

Turbine

The turbine is wings installed at the exhaust end where, by the pressure of exhaust gas, it rotates the compressor and
performs the role of transforming heat energy of exhaust gas into torque energy. The radial type is used as the turbine’s
wings. Therefore, during operation of the engine, the turbine receives temperature of exhaust gas and it rotates in high
speed, it requires to have sufficient rigidity and heat resisting property.

During operation of the engine, exhaust gas discharged through the exhaust valve of each cylinder makes turbine rotate
by coming in contact with the turbine’s wings from the outer circumference within housing of the turbine and is ex-
hausted through the exhaust manifold. At the same time, as the impeller is on the same shaft, it rotates.

Floating Bearing

Floating Bearing is a bearing, which supports the turbine shaft that rotates at about 10,000 to 15,000 rpm. It could be
rotated freely between the housing and the shaft as it gets lubricated by oil being supplied from the engine.

Impeller

Turbine shaft

Turbine

Floating bearing

Thrust collar

Impeller

Turbine

Exhaust gas

Oil passage

Diffuser

Notice

Stopping the engine immediately after driving at high speed stops oil from being supplied to the bearing and
may cause it to get burnt. Therefore, the engine must be stopped after cooling the turbo system by sufficiently
idling the engine.

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EXHAUST SYSTEM

DI ENG SM - 2004.9

Booster Pressure Control Valve Unit (Turbo Charger Actuator)

In order to reduce discharging of hazardous exhaust gas and to avoid the engine’s overrun the turbo charger must be
appropriately controlled. The maximum turbo charging pressure must be controlled as excessive increase in the pres-
sure and power output can cause critical damages to the engine. In order to control these, the booster pressure control
valve is installed on the turbo charger.

The difference of the booster pressure control between the existing IDI engine and DI engine is that in IDI engine, booster
pressure of the intake manifold operates the booster pressure control valve connected directly to the turbo charger
whereas in DI engine, the control is achieved by utilizing vacuum modulator (vacuum from a vacuum pump) designed to
control the booster pressure control valve. It operates booster pressure control valve by supplying electrical power to the
vacuum modulator having the amount of air being flown into the HFM sensor from the engine’s ECU as the base signal.

Refer to the EGR section in following pages for the function of turbo charger and HFM sensor in exhaust system.

Booster pressure control valve unit and vacuum modulator

Turbo charger booster

Turbo charger booster

vacuum modulator