SsangYong Actyon Sports II. Manual - part 34

06-19

1914-01

T-MAP sensor

Booster pressure and 
temperature

E-VGT turbocharger

Improves engine power

2. COMPONENTS

Engine ECU (D20DTR)

E-VGT duty control

Accelerator pedal position 

sensor

Transfers driver's will to 
accelerate to ECU

Atmospheric pressure, RPM 

signal

HFM sensor

Improves the engine power

Coolant temperature sensor

Operates the VGT according to 
engine warm-up

For details about control logic, refer to Chapter “Engine Control”.

*

06-20

3.  INPUT/OUTPUT DEVICES

06-21

1914-01

Control 

range

Turbocharger driving

mechanism

Control method

Effect

Improved 

performance

At low 

speed

Narrows the flow 
passage for the 
exhaust gas by 
folding the vanes

The flow rate is 
increased as the 
exhaust gas passes 
the narrow passage 
→ Increased 
turbine & impeller 
speed, Increased 
compressive force

Improved 

low speed torque

4. OPERATING PRINCIPLES

The E-VGT is designed to get more improved engine power in all ranges by controlling the turbine as 

follows:

1) How it Works at Low Speed

Normal turbocharger cannot get the turbo effect because the amount of exhaust gas is not enough and 

the flow speed is slow in a low speed zone, but VGT allows the flow passage of exhaust to narrow, 

resulting in increasing the flow speed of exhaust gas and running the turbine quickly and powerfully. 

Therefore, as VGT can intake more air than normal turbocharger, it can give the benefit of the increased 

output even in a low speed zone.

Turbocharger lag

The turbocharger is at idle speed when there is no load or it is in the normal driving condition. During 

this period, the amount of exhaust gas passing through the turbine is not enough to turn the 

compressor wheel (impeller) fast. Therefore, the intake air is not compressed as needed.

Because of this, it takes time for turbocharger to supply the additional power after the accelerator 

pedal is depressed. This is called "turbocharger lag". 

Basic principle at low speed

At low speed, it utilizes the principle of venturi. 

For example, when air flows through the venturi 

tube, the flow speed is faster and the pressure is 

lower at the point "A". In this case, if the inner 

diameter of venturi is more narrowed, the flow 

speed is so much faster (refer to the equation).

※ 

06-22

2) How it Works at High Speed

In a high speed zone, the amount of exhaust gas increases and it is accompanied with a great force. 

Therefore, if the inner diameter of venturi is more widened, the turbine in the turbocharger by the 

releasing force of abundant exhaust gas can deliver a more increased energy to the compressor. The 

output will increase in submission to the increase of intake air volume.

Control 

range

Turbocharger driving

mechanism

Control 

method

Effect

Improved 

performance

At high 
speed

Expands the 
flow passage for 
the exhaust gas 
by unfolding the 
vanes

The flow rate is 
increased due to the 
expanded 
passage→ 
Increased turbine & 
impeller speed, 
Increased 
compressive force

Improved 
maximum 
power