Boost control and vacuum line clean up

Discussion in 'Technical' started by Sketchy, May 16, 2017.

  1. Sketchy

    Sketchy Sick to the power of rad

    I hate all the shit that hangs off the side of these motors in terms of vacuum lines and boost control associated noise.

    Can I turf everything and just run a basic electronic boost controller while using the factory ecu (with Nistune)? If so, is there a step by step or how to on the best/easiest way to do it?
     
  2. MagicMike

    MagicMike Moderator Staff Member

    Off top of my head, you need:

    FPR reference
    boost gauge reference
    boost control reference
    Recirc/bov reference too

    Boost solenoid to wastegates (single feed tee'd to gates)

    Think that is about it if you delete all the usual stuff (AIV/PRVR etc)

    There is a very good vacuum guide in the tech section.
     
    Last edited: May 16, 2017
  3. SrAfciGeR

    SrAfciGeR Member

    Yes you can.
    This is what you need to do
    [​IMG]
    And block of the pressure source from turbo that you don't use.

    Image represents twin turbo manual boost controller.
    Only difference with electronic boost controller and manual valve is that you using solenoid which opening is regulated with the controller.

    Your ECU does contains boost map that you simply don't use in this case... All works as good but allows you to run more boost :)

    - For More boost you closing the valve
    - For Less boost you opening the valve
     
  4. rob260

    rob260 Administrator Staff Member

    No it doesn't... the ECU can reduce pressure via the safety boost solenoids in response to knocking or a knock sensor fault, but that's it. There's no map or boost control of any sort.
     
  5. SrAfciGeR

    SrAfciGeR Member

    Ok. .. Haven't got to the stage to tune mine as yet... Never the less newer ECU's do have boost maps.

    From what Rob explained above: Stock Nissans ECU by default are set to 7psi mark "which is bugger all" for this brilliant engine and if knock somehow appears, (which is highly unlikely at that pressure). ECU just opens boost solenoids, thus you loose all boost... And your engine survives another day... Big happy ending :)

    With aftermarket boost controller you skip all that nonsense anyway.
    Set it to what would you like to archive and discover all that power that you have been banned from :)
    Well don't go above 15psi and you'll be fine.
     
  6. IB

    IB ?????

    Err no, that's not what Rob said.

    The stock wastegate actuators set the boost to 7 psi. The wastegate solenoids add another 2 psi to make a total of 9 psi stock. Under certain circumstances the ECU will switch the wastegate solenoids so the boost drops to 7 psi to protect the engine.
     
  7. SrAfciGeR

    SrAfciGeR Member

    Preload settings on my stock wastegates were set to 7psi (which is around 0.5bar), on both turbos.
    So they start opening before that level , you might see 9psi on the boost gauge but those wastegates letting quite some pressure out at that stage...
    According to Rob's description: If knock signal is detected by ECU. Same ECU sends the signal (usually pules voltage) to the solenoids to shut the valves down. By doing so pressure in actuator's diaphragm increases and wastegates valve open's up a bit more till the excess pressure drops and knock signal is no longer detected.
    ECU then stop sending the signal to the solenoids and valve opens. Wastegate spring then continues to regulates the boost pressure of 7psi.

    There you go...
     
  8. IB

    IB ?????

    Once again, you have not understood what Rob has posted or how the Z32 TT ECU interfaces with the turbos.

    Stock boost is 9 psi, safety boost is 7 psi.

    The ECU only controls the wastegate solenoids and does not know what the boost pressure is.

    Getting back on subject for this thread, with the wastegate solenoids disconnected, bypassed or deleted, you can use an aftermarket boost controller to set control the boost to a pressure of 7 psi or higher.
     
    Last edited: May 18, 2017
  9. stumagoo

    stumagoo Active Member

    the guys are right, the stock Z system has little boost jets (restrictors) just before the waste gates. the ecu opens the solenoid and in combination with the jets this bleeds boost pressure away from the wastegate, opening them at 9psi. if the ecu detects knock or a fault with the knock sensor it closes the solenoids allowing full boost pressure to the wastegae opening them at spring pressure of 7 psi. In reality they are using a fancy set up similar to a bleed tee (manual boost controller). there is Absolutley no referencing boost pressure in the ecu with this system
     

Share This Page