Wastegate Control; Engine Speed Below 5,300 Rpm; Engine Speed Above 5,300 Rpm - Mazda 323 Workshop Manual Supplement

TURBOCHARGER CONTROL [BP TURBO]
F2
WASTEGATE CONTROL
The engine control unit controls the wastegate
solenoid valve to give higher boost to the engine in the higher
rpm range, increasing engine torque
and power.
System
Diagram
I
t
1
ECU
i i
AIRFLOW METER
ACTUATOR
\
WASTEGATE
WASTEGATE
SOLENOID VALVE
r
ACTUATOR
WASTEGATE SOLENOID VALVE
: OFF (VALVE CLOSED)
ACTUATOR
BOOST
PRESSURE
WASTEGATE SULENOlD VALVE
: ON (VALVE OPEN)
Operation
Engine speed below 5,300 rpm
The
wastegate solenoid valve is OFF. Boost pressure is
ap-
plied
directly
to the actuator
and the wastegate opens when
the boost pressure exceeds 49 kPa (0.5 kg/cm , 7.1
psi).
Engine speed above 5,300 rpm
The wastegate
solenoid valve is
UN.
Some boost
pressure is
bypassed
to the intake manifold, limiting the opening of the
wastegate to increase boost pressure and
improve
engine per-
formance.
F2-13