Variable Induction System: Description and Operation

VARIABLE INDUCTION SYSTEM

Intake Manifold Long Tract:

Intake Manifold Short Tract:

PURPOSE
A multi-path intake manifold is used on the V6 engine. The manifold incorporates two intake air paths which have different lengths and diameters. One air path is 780 mm long and small diameter, this provides high torque at low engine speed. The other air path is 380 mm long and large diameter, the benefit of a shorter larger diameter path is increased power at higher rpm.

OPERATION
The multi-path manifold changes air paths with six flaps that are opened and closed by a vacuum servo, the Intake Manifold Change-Over Vacuum Servo. Vacuum to the servo is electrically controlled using a solenoid valve, the Intake Manifold Change-over Valve. The intake manifold change-over valve is activated by a signal from the ECM. The six flaps operate according to engine speed. They are closed up to 4100 rpm for maximum low-end torque and above 4100 rpm they open completely for higher power output.