Variable Valve Timing Solenoid: Description and Operation

INTAKE MANIFOLD RUNNER CONTROL (IMRC) SOLENOID




The characteristic torque curve of a normally aspirated engine depends mainly on how the engines average pressure changes over the engine speed band. The average pressure is proportional to the volume of the air mass present in the cylinder when the inlet valve is closed. The design of the inlet system determines how large an air mass can be drawn into a cylinder at a given engine speed.

An intake manifold runner control (IMRC) valve (2) is used to change the intake manifold runner configuration. When the IMRC valve is open, the intake manifold is configured to one large plenum (4). When the IMRC valve is closed, the intake manifold is configured to two smaller plenums (3). The two intake manifold runner sizes result in different torque curves which improves performance at low and high engine speeds. The IMRC valve is located in the intake manifold (1). The IMRC valve solenoid is supplied with ignition 1 voltage and is controlled by the engine control module (ECM).