INTAKE SYSTEM


  1. CONSTRUCTION


    1. A wastegate valve is used for the turbocharger sub-assembly, so that when the vehicle is being driven at low load (supercharging not necessary), the back pressure decreases, reducing pumping loss during the exhaust stroke according to the wastegate valve opening. In addition, by opening the wastegate valve even when the engine is started, high temperature exhaust gas is supplied to the catalyst, shortening warm-up time.

    2. An electric wastegate actuator is used, allowing for fine boost pressure control. The electric wastegate actuator opens and closes the wastegate valve according to signals received from the ECM.

    3. A wastegate valve is used in the turbocharger sub-assembly. When the vehicle is being driven at low load (supercharging not necessary), the wastegate valve opens to decrease the back pressure and reduce pumping losses during the exhaust stroke. Also, the wastegate valve opens during start-up to decrease the amount of time needed for the catalyst to warm up.

    4. An electric air by-pass valve is used in the air tube sub-assembly to prevent the surge phenomenon* from occurring. When the throttle valve closes with the accelerator pedal released, the pressure between the turbocharger sub-assembly and throttle valve increases. This pressure is diverted upstream to the turbocharger sub-assembly when the air by-pass valve opens.

      Tech Tips

      * Surge phenomenon: This phenomenon is when the intake airflow reverses. As a result, an abnormal noise is easily generated during deceleration.

      B005682C01
      *1 Turbocharger Sub-assembly *2 Wastegate Valve Actuator
      *3 Turbine Wheel *4 Compressor Wheel
      *5 Wastegate Valve - -
      *a Exhaust Gas *b Intake Air
      *c Bypass Gas *d View from A

  2. OPERATION


    1. Wastegate Valve


      1. When the engine is stopped, the wastegate valve is open.

      2. The electric wastegate actuator operates according to signals from the ECM and opens the wastegate valve after a specified amount of time elapses after starting the engine with a light engine load.

      3. When the engine is under high load or accelerating, fine control is performed to open and close the wastegate valve.

        Figure 1. Wastegate Valve Opened

        B0056IOC01
        *1 Compressor Wheel *2 Turbine Wheel
        *3 Wastegate Valve *4 Wastegate Valve Actuator
        *5 ECM - -
        B0056J1 Exhaust Gas B005637 Intake Air

        Figure 2. Wastegate Valve Closed

        B0056IGC01
        *1 Compressor Wheel *2 Turbine Wheel
        *3 Wastegate Valve *4 Wastegate Valve Actuator
        *5 ECM - -
        B0056J1 Exhaust Gas B005637 Intake Air

    2. Air By-pass Valve


      1. The air by-pass valve assembly opens according to signals from the ECM to divert the pressure between the turbocharger sub-assembly and throttle valve, which is increased when the throttle valve is closed, upstream of the turbocharger sub-assembly.

        Figure 3. Air By-pass Valve Closed

        B0056N1C01
        *1 ECM *2 Air By-pass Valve Assembly
        *3 Compressor Wheel *4 Turbine Wheel
        *5 Coil *6 Shaft
        *7 Valve - -
        *a To Throttle Body with Motor Assembly *b Air By-pass Valve Assembly Cross Section
        B0056J1 Exhaust Gas B005637 Intake Air

        Figure 4. Air By-pass Valve Open

        B0056L9C01
        *1 ECM *2 Air By-pass Valve Assembly
        *3 Compressor Wheel *4 Turbine Wheel
        *5 Coil *6 Shaft
        *7 Valve - -
        *a To Throttle Body with Motor Assembly *b Air Bypass Valve Cross Section
        B0056J1 Exhaust Gas B005637 Intake Air