SFI SYSTEM


  1. FUNCTION


    1. For the turbocharger control, wastegate valve control which controls the turbo pressure and air by-pass valve control which prevents the surge phenomenon* are used.

      Tech Tips

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


      1. The ECM cooperatively controls the throttle valve, Dual VVT-i and wastegate valve to achieve a driving condition with optimal fuel efficiency during normal driving. Also, the ECM controls each actuator in accordance with the driver's intentions during acceleration to achieve a high torque response.

    2. Wastegate Valve Control


      • The wastegate valve actuator assembly opens and closes the wastegate valve according to signals from the ECM.


      1. During Light Loads


        • Opening the wastegate valve reduces the pressure of the exhaust manifold and improves fuel efficiency by achieving a reduction in pumping loss and improved combustion (reduction of remaining gas).

      2. During Acceleration and High Loads


        • Closing the wastegate valve increases the engine torque and improves responsiveness during acceleration.

        B0056QGE01

        Tech Tips

        During racing, the wastegate valve is open and the opening and closing operation does not operate.

    3. Air By-pass Valve Control


      1. The ECM opens and closes the air bypass valve in accordance with driving conditions to prevent the surge phenomenon.

        B0056D8E01

        Tech Tips


        • During racing, the air by-pass valve is closed and the opening and closing operation does not operate.