Exhaust by-pass valve controlled by what? | FerrariChat
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Exhaust by-pass valve controlled by what?

Discussion in '348/355' started by sunline, Feb 19, 2009.

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  1. sunline

    sunline Karting

    Dec 23, 2004
    155
    Ashburn Virginia
    Full Name:
    Ken
    #1 sunline, Feb 19, 2009
    I just had a new ECU put in my 5.2 355 and immediately noticed a change in the exhaust sound when the rpms got over 5k. I assume this is the by-pass valve opening up. Oddly enough I have never noticed such a difference in the exhaust decibel level as I do now and am beginning to think that the valve may not have been opening in the past. Could replacing the faulty ECU be responsible for the valve now opening? The only other work that was done was a factory campaign 148 which replaced the OBDII connector wire and pin.
     
  2. f355spider

    f355spider F1 World Champ
    Owner Rossa Subscribed

    May 29, 2001
    18,055
    USA
    #2 f355spider, Feb 19, 2009
    ECU for what? There is the Motronic ECU, catalyst ECU's, suspension ECU, etc. The Motronic ECU which controls the overall engine management, does directly control the exhaust valve operation as well. What required replacement of this ECU?
     
  3. sunline

    sunline Karting

    Dec 23, 2004
    155
    Ashburn Virginia
    Full Name:
    Ken
    #3 sunline, Feb 19, 2009
    The catalyst ECU
     
  4. zero

    zero Guest

    Apr 24, 2007
    776
    #4 zero, Feb 19, 2009
    Engine vacume opens a 355 by-pass valve, there is no electrical trickery involved. Some times they dont open because there can be s simple split in the short rubber pipe that conects to the by-pass valve.
     
  5. Loser

    Loser Formula Junior

    Apr 11, 2008
    791
    Gilroy, CA
    Full Name:
    Tom
    #5 Loser, Feb 19, 2009
  6. gothspeed

    gothspeed F1 World Champ

    May 26, 2006
    10,244
    U.S.A.
    Full Name:
    goth
    #6 gothspeed, Feb 19, 2009
    Indeed Zero! ............ engine vacuum provides the muscle :) ............... though the engine vacuum is rationed by a solenoid valve controlled by the engine ECU ........... :eek:

    Though on the 360, it may be controlled by engine vacuum alone ....... :cool:
     
  7. sunline

    sunline Karting

    Dec 23, 2004
    155
    Ashburn Virginia
    Full Name:
    Ken
    #7 sunline, Feb 19, 2009
    Back to the original question .... Will just replacing the catalyst ECU affect the opening and closing of the bi-pass valve? Something caused the valve to start opening and that was the only thing that was done.
     
  8. darrenliu

    darrenliu Formula Junior

    Jun 24, 2008
    450
    Melbourne Australia
    Full Name:
    Darren Liu
    #8 darrenliu, Feb 19, 2009
    is this true, the 360 doesn't have a vacuum reserviour tank or a solenoid valves to modulate the vacuum supply?
     

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