Variable Resonance Induction System (VRIS)

PURPOSE
The variable resonance induction system (VRIS) is designed to improve engine performance (torque output) over a wide RPM range by manipulating pressure waves in the intake manifold plenum (dynamic chamber).

View: Variable Resonance Induction (VRIS) System:

CONSTRUCTION
The inside of the dynamic chamber is divided into two sections. Two shutter valves are installed in the connecting pipes for variable resonance in the induction system.

Variable Resonance Induction System (VRIS) Control Devices:

Two vacuum chambers (under the intake manifold) are used to supply constant vacuum to the VRIS shutter valve actuators during wide-open throttle operation and other low-vacuum, low-speed situations.

VRIS Operation Chart:

OPERATION
This system opens and closes the shutter valves according to the engine speed to improve the charging efficiency by utilizing the pressure waves of the intake air.
The system takes advantage of high and low pressure oscillations in the intake manifold created by the opening and closing of the intake valves. As one intake valve closes, air compresses behind the valve. When the air rebounds, a pressure wave travels through the intake manifold, forcing air to fill other cylinders. The engine speed at which this is effective is varied by changing the effective volume of the manifold and the length of the passage between the cylinders. To do this, the shutter valves are opened and closed at different engine speeds. Vacuum to the shutter valve actuators is controlled by the powertrain control module engine (PCME) via two VRIS control solenoid valves.