charging JAGUAR S TYPE 1999 1.G Powertrain Manual

V6 EngineAJ-V6/AJ28
21
Air Induction System
range, the manifold geometry can be set to three
different configurations, each of which maximises
the tuning effect over different parts of the range.
This variable geometry is achieved by the use of
two gate valves, the intake manifold tuning (IMT)
valves, which are controlled by the engine
management system.Air Intake
The air induction system consists of the intake
ducting and air cleaner, the throttle body, tuned
manifold assembly and lower manifold (see Fuel
System).
The air cleaner connects to the throttle body via a
lateral mounted intake pipe with resonator box. A
separate duct, housing the MAF sensor, fits
between the air cleaner and resonator pipe. The
IAT sensor is located in the intake resonator pipe.
Variable Intake System
(see illustration on page 23)
The induction manifold is specially designed to
optimise torque across the engine speed/load
range. The air charge enters the induction
manifold from the throttle body and passes
through a plenum chamber for distribution to the
cylinders via the manifold runners. The function
of the plenum chamber is to provide a resonance
(or maximising) effect such that large pulses of
charge air are produced which will arrive at the
inlet ports at the correct time for induction into
the cylinders. This ram charging action is only
effective over a restricted speed/load range for a
particular plenum chamber volume and geometry.
To extend the effect over the whole engine speed
J.303.1379
AIR INTAKE
J.303.1379
Air CleanerIntake DuctingMAF Sensor
IAT SensorThrottle Body
Tuned Manifold Assembly