1.1.2. Wastegated turbocharging system
1) What is the wastegated turbocharging system?
Turbocharger is a system designed to pressurize the intake air to increase engine output and
decrease fuel consumption by using the energy of exhaust gas discharged from the engine.
However, the turbocharger has a weak point at low engine speed, its performance may drop,
thus performance at low speed is relatively low.
The WASTEGATED TURBOCHARGING SYSTEM is an up-to-date turbocharging system
remedying such a defect, and the working principle is as follows:
A small-sized high performance turbine is used to improve engine performance at low
speeds. As high charging efficiency can be obtained even If a small amount of exhaust gas
is present at low speed. On the other hand, if higher charging pressure is produced than
what is present at high speed, fuel consumption increases. To correct this, part of exhaust
gas is forced to be discharged into the exhaust manifold through the waste gate, not through
the turbine.
The waste gate is controlled by the ACTUATOR mounted in the turbocharger, and if the
pressure in the turbocharger becomes higher than what is required for the engine, the waste
gate is forced to open.
2) DE12T, DE12TI and DE12TIS engines are featured by the application of turbochager so that
the torque in low speeds can be increased by 30% or more, not only to create high perfor-
mance, just from the time of starting off the vehicle but also to greatly reduce fuel consump-
tion.
- 2 -
Compressed air outlet por
Intake air
Turbine
Turbine port
Exhaust gas
outlet port
Waste gate
Compressor
Actuator
EQM1003I
<Figure 1-3> Turbochager