final verdict for by-pass valve - open vs closed | FerrariChat
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final verdict for by-pass valve - open vs closed

Discussion in '348/355' started by CANDREAM, Oct 5, 2011.

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  1. CANDREAM

    CANDREAM Canada

    Nov 13, 2009
    407
    Burlington, Ontario
    Full Name:
    Sadi
    #1 CANDREAM, Oct 5, 2011
    Gents, I am trying to come up with the final verdict, if that is possible among the Gurus, and to help the newbies about the By-pass valve open concerns.

    In summary, if you wire the by pass open with an oem muffler, you will get damage due to the back flow and high temperatures. If you have a capristo/other similar design muffler, you can run an open valve set up since the exchaust gases are not mixed and the temps are within limits.

    DO we agree ???????


    Please see bleow capristo responce to my question.
    ==================================================
    That brings us to your second question. the Capristo exhaust you already own eliminates this problem. The flow path through the Capristo does not allow the reverse flow that causes the damage to the exhaust system. On the OEM exhaust the exhaust gases could ,with the valve open, flow back through the catalytic converters and remix this hot gas with new exhaust gas. This cycle would repeat through the Y-pipe and exhaust until temperatures rose to damaging levels. This only occurred in a narrow range of parameters, but the damage is nasty.
     
  2. junglistluder

    junglistluder F1 Rookie
    Owner Silver Subscribed

    Mar 23, 2007
    3,631
    VA
    Full Name:
    Brendan
    #2 junglistluder, Oct 5, 2011
    Keep it closed (stock). I had mine wired for a bit, but went back to stock and it runs much better at low rpms. The sound is better too.
     
  3. Monteman

    Monteman Formula 3
    Rossa Subscribed

    Feb 9, 2006
    2,348
    Santa Barbara, CA
    Full Name:
    Monte
    #3 Monteman, Oct 5, 2011
    Last edited: Oct 5, 2011
    Not going to respond in fear that we'll lose our bi-monthly threads on this and I will have nothing to follow or rant on ;)

    Seriously, there are three to four people in the US that I consider true, long term, in depth experts on the 355 which is how I drew the opinion I have today. They know more about the 355 than I'll ever hope to. So I'll see if they weigh in or not but I do not have the expertise nor facts to agree or not. I based my opinion on the facts presented on what happens if the valve is wired open with a stock configuration. I can't speak to the Capristo type configuration and would defer to the experts.
     
  4. Rob'Z

    Rob'Z Formula 3

    Mar 29, 2008
    1,024
    Tucson,AZ
    Full Name:
    Robert
    #4 Rob'Z, Oct 5, 2011
    I'll go ahead and agree with that assessment.
     

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