IMT (Intake Manifold Tuning) System: Description

IMT system consists of the following items:

IMT valve (1) installed between intake manifold and surge tank pipe
IMT valve actuator (4)
IMT vacuum solenoid valve (2)
Vacuum tank (3)

Vacuum tank contains the one way check valve (5) to maintain negative pressure constantly regardless of variation in the intake manifold pressure.

Vacuum tank, therefore, supplies IMT vacuum solenoid valve actuator with stable negative pressure in whole engine speed ranges.

Fig 1: Identifying IMT Valve Actuator & IMT Vacuum Solenoid Valve

Courtesy of SUZUKI OF AMERICA CORP.

IMT system varies the effective length of intake pipe by opening and closing IMT valve in order to improve an air volumetric efficiency.

When IMT valve is fully open [A]:

The effective length of intake pipe is short.

With this condition, the engine torque is large at low and middle-high engine speed ranges.

However, the engine torque is small at middle-low and high engine speed ranges.

When IMT valve is totally closed [B]:

The effective length of intake pipe is long.

With this condition, the engine torque is large at middle-low and high engine speed ranges.

However, the engine torque is small at low and middle-high engine speed ranges.

IMT system utilizes this characteristic of engine. IMT valve is opened at low and middle-high engine speed ranges, and closed at middle-low and high engine speed ranges.

In this way, engine torque is improved in whole engine speed ranges.

Fig 2: IMT Valve Graph

Courtesy of SUZUKI OF AMERICA CORP.