#
VARIABLE INTAKE-AIR SYSTEM (VIS) [ZY]

id0113001196c8

## Outline

• The function of the VIS is essentially carried over from that of the current Mazda6 (GG, GY) L3 engine models, except for the following:

  - A motor-type shutter valve actuator has been adopted. The shutter valve actuator receives the VIS operation signal from the PCM.
  - Operation condition has been changed.

## Structure

• The VIS is composed of the VIS shutter valve actuator and VIS shutter valve.
System diagram

## Operation

### Engine speed less than approx. 4,100 rpm (VIS shutter valve closed)

  • The VIS shutter valve closes by the operation of the VIS shutter valve actuator.
  • Under this condition, the effective intake manifold length is the length from the intake valve to the dynamic chamber (C to A). The intake air inertia effect is obtained at low or middle engine speeds via this long intake passage, intake airflow amount in the cylinder increases, and higher torque at low or middle engine speeds is obtained.

### Engine speed approx. 4,100 rpm or more (VIS shutter valve open)

  • The VIS shutter valve opens by the operation of the VIS shutter valve actuator.
  • Under this condition, the effective intake manifold length is the length from the intake valve to the dynamic chamber (C to B). The intake air inertia effect is obtained at high engine speeds via this short intake passage, intake airflow amount in the cylinder increases, and higher torque at high engine speeds is obtained.