Intake Manifold Tuning Valve System Description

Intake Manifold Tuning Valve System Description

Intake Manifold Tuning (IMT) Valve System

The intake manifold tuning (IMT) valve system uses variable air induction tuning in order to achieve maximum performance and efficiency over the entire operating range of the engine. The characteristic torque curve of a normally aspirated engine depends mainly on how the engines average pressure changes over the engine speed range. 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 IMT valve is used to change the intake manifold plenum configuration. When the IMT valve is open, the intake manifold is configured to one large plenum. When the IMT valve is closed, the intake manifold is configured to 2 smaller plenums. The 2 intake manifold plenum sizes result in different torque curves, which improves performance at low and high engine speeds. During low speed, high load conditions the IMT valve is closed creating a longer runner path inside the plenum, which increases torque. During higher engine speeds and loads, the IMT valve opens creating a shorter runner path inside the plenum, which increases horsepower.

The IMT Valve assembly consists of the following:

* A tuning valve
* A micro-processor
* An electric motor
* A hall-effect sensor
* An ignition voltage circuit
* A ground circuit
* An IMT Valve control circuit
* An IMT valve signal circuit

Ignition Voltage Circuit

An ignition voltage is supplied directly to the IMT valve assembly terminal A from the powertrain relay through a fuse. The ignition voltage provides power to a microprocessor and to a motor that rotates the IMT valve within the intake manifold.

Ground Circuit

Ground circuit is supplied directly to the IMT valve assembly terminal B. This circuit provides ground for the micro-processor and the motor.

IMT Valve Control Circuit

During operation when the valve is open the control module applies ground to the IMT valve control circuit which indicates to the microprocessor within the IMT valve to position the valve to the closed position which turns the motor ON and rotates the IMT valve within the intake manifold plenum. The IMT Valve Control Circuit is supplied to the IMT Valve at terminal C.

IMT Valve Signal Circuit

When the IMT valve is rotated the hall-effect sensor is reporting the position of the valve to the engine control module (ECM). The control module uses this feedback signal to determine the position of the IMT valve. The IMT Valve Signal circuit is supplied to the IMT Valve at terminal D

Typical Scan Tool Data