NEXON

1.5L REVOTORQ ENGINE

COMPONENTS

A. Exhaust Manifold

The exhaust manifold is mounted on the cylinder

head. The exhaust gases are trapped out from the

engine through the exhaust manifold.

B. Turbocharger

(VGT)

Compared to traditional turbochargers a Variable

Geometry Turbocharger

(VGT)

has better perfor-

mance at low engine speeds and a low boost

threshold. The geometry of a VGT keeps varying

with engine speed to provide optimum boost. Hence

even at low engine speeds it is able to produce the

required boost.

The actuation for geometry change is controlled by

the EMS ECU instantaneously and progressively.

This gives smooth and better drive ability. The boost

control over the entire speed/load is adjusted such

that it reduces the vehicle emission.

CONSTRUCTION AND FUNCTION

The VGT has a set of movable vanes in the turbine

housing, and they control the boost. At low engine

speeds when exhaust flow is low, the vanes are

partially closed. This increases the pressure of the

exhaust gases pushing against the turbine blades,

making the turbine spin faster and generating more

boost. As engine speed increases, so does the ex-

haust flow, so the vanes are opened to reduce

turbine pressure and hold boost steady or reduce it

as needed. By reading the manifold pressure sen-

sor, the ECU can adjust turbine inlet pressure

(by

varying the Geometry of Vanes)

instantaneously to

control the boost at any speed/ load and to limit

boost at full load.

ADVANTAGES / FEATURES



Good low end torque.



Good transient response.



Good fuel economy.



Increased useful engine operating range.



It provides more matching level of pressure

boost even to a slow spinning turbine without

providing too much of a boost at higher speed.



VGT is electronically controlled and pneumatical-

ly actuated.



Low engine noise.



Lower emission.

SYSTEM FLOW

For system flow schematic refer exhaust system

schematic layout.

The exhaust gases are made to pass through the

turbocharger turbine which will rotate the compres-

sor mounted on the same shaft on the air inlet side.

The air from the air filter is sucked by VGT com-

pressor. The compressed air then flows through an

intercooler and then to the intake manifold. For

more information refer Air intake system.

PRECAUTIONS



Avoid Lifting the turbocharger by holding the ac-

tuator.



Avoid Lifting turbocharger holding the rod end.



Avoid Lifting turbocharger holding the compres-

sor side.



Hold the turbo-charger at the turbine housing

/center housing.