SFI SYSTEM


  1. FUNCTION


    1. For the turbocharger control, wastegate valve control which controls the turbo pressure and air bypass 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 easily generated during deceleration.


      1. The ECM cooperatively controls the throttle valve, VVT-iW, 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


      1. During Engine Start


        • The ECM controls the vacuum regulating valve assembly to block the vacuum from the vacuum pump assembly to the actuator and open the wastegate valve. As a result, high temperature exhaust gases are supplied for the catalyst and warm-up time has been reduced.

      2. During Light Loads


        • The ECM controls the vacuum regulating valve assembly to block the vacuum from the vacuum pump assembly to the actuator, opening the wastegate valve and decreasing the exhaust manifold pressure. As a result, fuel economy has been enhanced due to reduced pumping loss and improved combustion (reduction of remaining gas).

      3. During Acceleration and High Loads


        • The ECM controls the vacuum regulating valve assembly to control the vacuum from the vacuum pump assembly to the actuator and close the wastegate valve. As a result, engine torque increase and response during acceleration have been achieved.

        A001N53E01

    3. Air Bypass Valve Control


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

        A001MZNE01