Active Exhaust Valve Question

Discussion in 'SRT Hellcat General Discussions' started by (CH) Challenger, Jan 10, 2017.

  1. (CH) Challenger

    (CH) Challenger Rookie

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    1. When I disconnect the connector from actuator is the flap open or closed?
    (Vehicle parked. Engine off. Ignition off.)


    2. If the actuator currentless (wiring connector disconnect) the flap/valve itself can rotate or not?
    Or otherwise: is the flap fixed with currentless valve?


    I know the MIL lamp is lit when I unplug...
     
  2. Radride

    Radride Silver Member

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    Actuators fail closed. If no power to them, they remain closed. That's why you need to buy that kit that props open the valves and ziptie your actuators to the bottom of your car.

    R.K.
     
  3. (CH) Challenger

    (CH) Challenger Rookie

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    Is there a spring in the actuator that closes the valve?
     
  4. Radride

    Radride Silver Member

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    I believe so.

    R.K.
     
  5. rayzazoo

    rayzazoo DRIVESRT.COM Gold Supporting Member

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    When the vehicle is off, the valves are open (see attached picture).

    Untitled.png

    When the vehicle starts, the actuators rotate the springs to close the valves (ie., when there is a current through the actuator, the valves close). They are then controlled by the PCM to modulate partial open/full open (e.g. track mode). If the actuators fail or are disconnected, the valves remain open and you get a MIL.
     
  6. (CH) Challenger

    (CH) Challenger Rookie

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    Is the flap fixed with currentless valve?
     
  7. rayzazoo

    rayzazoo DRIVESRT.COM Gold Supporting Member

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    I think you mean to say, when the electronic actuators fail, the valves remain open. When the spring is engaged, the valves close. If actuators failed while the engine was running, there would be no fail-safe if the valves failed in a closed position (exhaust pipe clog).
     
  8. rayzazoo

    rayzazoo DRIVESRT.COM Gold Supporting Member

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    When there is no current through the actuator, the valve remains open. When there is a current through the actuator, it twists the spring which closes the valve.

    In startup and check mode, when you turn on the ignition, the valve cycles from open-close-open. When you unplug and re-plug the actuator (even with engine/ignition off), it also cycles open-close-open.

    If the actuator is disconnected, the PCM will throw a MIL sensing that the actuator has failed. The mechanical fail-safe is the valve will remain open.
     
  9. (CH) Challenger

    (CH) Challenger Rookie

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    Ok, thanks!
     
  10. rayzazoo

    rayzazoo DRIVESRT.COM Gold Supporting Member

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  11. Radride

    Radride Silver Member

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    Sorry. You're correct.

    R.K.
     
  12. rayzazoo

    rayzazoo DRIVESRT.COM Gold Supporting Member

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