Variable Dynamic Effect Intake - Mazda RX-7 1989 Service Highlights

VARIABLE DYNAMIC EFFECT INTAKE (VOl) SYSTEM
~.-
s systern cors.sts of the VOl valve, solenoid valve, and actuator. The VOl valve is built into the exten mani-
.
~
:::: Ooerat on of th1s system is as shown below.
-OeENGINE
~
~=EED
OPEN V %
,
·.
~
. .
.....
• • • PRESSURE WAVE
ABOVE
5,200 rpm
:: :.·,.; ANGLE SENSOR
0
HIGH ENGINE SPEED
J
(VDI VALVE: OPEN CONDITION)
LARGE
INTAKE AIR
AMOUNT (m
1
/h)
VDI VALVE
=
INTAKE AIR
•
·~
PRESSURE WAVE
co...,
VDI VALVE
OPENING
AREA
_______ JI
SMALL~--------~------~
0
5,200 8,000
ENGINE SPEED (rpm)
97UOF1 509
:
-::~;Jine
operation, when intake air flows to a port closed by the rotor a pressure wave is created.
:
·-::::s~re
wave then goes toward the open intake port, compressing the intake air along the way. At
~~-::speed,
the VOl valve is closed, causing the pressure wave path to be long. At high engine speed,
. ::: . :: . e opens and the pressure wave quickly pressurizes the intake air through the shortened path.
·· . :: '::xced 1nto the combustion chamber at all engine speeds.
:·-:: c-essunzation is induced at the time of the opening of the intake port, when the high-pressure
,· ;:::s
remaining in the working chamber generates strong pressure waves that rush into the intake
F1-12
I