SsangYong Korando III (2010 year). Manual — part 49

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1. SYSTEM DESCRIPTION OF E-VGT
(Electric-Variable Geometry Turbine)

A turbocharger is a centrifugal compressor powered by a high speed turbine that is driven by an engine's

exhaust gases. Its benefit lies with the compressor increasing the mass of air entering the engine (forced

induction), thereby resulting in greater performance (for either, or both, power and efficiency). As the

turbine, at exhaust end, is rotated 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 improving the

volume efficiency. Also, the exhaust efficiency improves as the exhaust turbine rotates. The

turbocharger is often referred to as the exhaust turbine turbocharger.

The E-VGT system installed to the D20DTF engine variably controls the passages of the turbine

housing to regulate the flow rate of the exhaust gas. The actuator of E-VGT is a DC motor actuator (E-

Actuator) which controls more quickly and precisely than the previous vacuum type actuator.

The engine ECU controls the E-Actuator electronically as follows:

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.

At low speed: Narrows the flow passage for the exhaust gas, resulting in increasing the flow speed

of the exhaust gas and running the turbine quickly and powerfully.

At high speed: Expands the flow passage for the exhaust gas, resulting in increasing the mass flow

of the exhaust gas and running the turbine more powerfully.

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Maximizes the intake air charging efficiency (Approx. 15%)

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Optimizes the exhaust gas flow rate by controlling the vanes inside the turbine housing with the E-

Actuator.

1.

(2) E-Actuator (Electric-Actuator, Rotary type)

Target temperature and airflow control

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Enhanced emission control: By temperature control with CDPF system

1.

(1) Performance (for EURO V)

Has a faster response time than the conventional vacuum actuator

2.

Improved low speed torque, high speed power and fuel economy.

Improved acceleration performance with rapid response time of vane

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1) Features

Features

Benefits

Folding and unfolding of the vane

is controlled electrically

Easy to get low speed air volume

Rapid response time

Electric control

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Improved low speed torque

Improved low speed torque and

power

Reduced exhaust gas

Improved fuel consumption

Improved acceleration

performance

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T-MAP sensor

Boost pressure and

temperature

E-VGT turbocharger

Improves engine power

2. COMPONENTS

Engine ECU (D20DTF)

E-VGT duty control

Accelerator pedal position

sensor

Transfers accelerating demand

to ECU

Atmospheric pressure, RPM

signal

HFM sensor

Improves the engine power

Coolant temperature sensor

Operates the VGT according to

engine warm-up

For more information about control logic, refer to Chapter "Engine Control".

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3. INPUT/OUTPUT DEVICES