355 - Capristo Bypass Remote: anyone running one? | FerrariChat

355 Capristo Bypass Remote: anyone running one?

Discussion in '348/355' started by DaisyCutter, Feb 1, 2019.

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  1. DaisyCutter

    DaisyCutter Karting

    Jul 15, 2014
    249
    Sweden
    Full Name:
    Dayan
    Hi all,

    After a year of running the Capristo Stage 2, while it sounds magnificent when I do bury the throttle it, most of the time I'm tootling around with the valve closed and hence missing the music. So, I'm looking at fitting the Capristo Bypass Remote to enjoy a little more of the lovely sound. Anyone here with experience running such a device on their car? Any down sides?

    Cheers in advance.
     
  2. kenneyd

    kenneyd Formula 3
    Silver Subscribed

    Sep 30, 2014
    1,944
    NE FL
    Full Name:
    Ken
    I have one sitting on my tool box. I plan on installing it soon, just haven't got around to it.
     
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  3. INTMD8

    INTMD8 F1 Veteran
    Owner

    Jun 10, 2007
    6,485
    Lake Villa IL
    DaisyCutter likes this.
  4. DaisyCutter

    DaisyCutter Karting

    Jul 15, 2014
    249
    Sweden
    Full Name:
    Dayan
    Just brought the car out to test the bypass remote functionality. For those of you thinking about doing it, do it. All the joy of the Capristo growl and scream when you want it, then shut it down to a modest (neighbourly-friendly) level when you need to. The perfect exhaust set-up.
     
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  5. f355spider

    f355spider F1 World Champ
    Owner Rossa Subscribed

    May 29, 2001
    17,913
    USA
    For OBDII (Motronic 5.2) it will likely cause "check engine" lights. Two things can cause the CE lights. One is with the bypass valve always open, the thermoprobe just past the valve will detect the hot exhaust gases constantly. When the Motronic is expecting the valve to be closed, this will set a CE light. The other cause is with the majority of the exhaust taking the path of least resistance through the bypass, insufficient exhaust will pass over the pre-catalyst O2 sensors, causing fuel trim errors, again tripping a CE light. These errors could likely be eliminated by an experienced technician. One could move the pre-catalyst O2 sensors to the merge collector on the exhaust manifolds, and the thermoprobe could probably be fooled with some trickery. ;)
     
  6. kenneyd

    kenneyd Formula 3
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    Sep 30, 2014
    1,944
    NE FL
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    Ken
    The easiest way to fix the thermal probe check engine light, it's simply just to remove the probe, cap the bung and zip tie the probe out of the way.
     
  7. f355spider

    f355spider F1 World Champ
    Owner Rossa Subscribed

    May 29, 2001
    17,913
    USA
    I am doubtful that will work on the 5.2 Motronic. The Motronic is expecting higher temp from the probe when the valve is open and a lower temp when the valve is closed. How would removing the probe prevent the CE light?
     
  8. kenneyd

    kenneyd Formula 3
    Silver Subscribed

    Sep 30, 2014
    1,944
    NE FL
    Full Name:
    Ken
    My understanding is the computer is only looking for heat, It doesn't care if its cold. source: https://www.ferrarichat.com/forum/posts/141662316/
    Before I bought a capristo for my 5.2, I had a 2.7 challenge exhaust on it and I did just as I described, I simply zip tied it away. 4 years with no codes, and no slow down lights.

    There is still the 02 sensor issue, I suppose if you drive to must with the valve open, It may get a O2 sensor related code
     
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  9. DaisyCutter

    DaisyCutter Karting

    Jul 15, 2014
    249
    Sweden
    Full Name:
    Dayan
    To clarify, my car is a 2.7 so no thermocouple after the bypass valve. In theory the pre-cat O2 sensors (and subsequent fuel trim) should be affected by this change in exhaust gas flow but I've only really had the valve constantly open when enthusiastically driving. On constant light throttle cruising switching it back to the default operational settings just makes sense as the noise level is a little intrusive. So far there have been no SDL/Check Engine lights. Will update if I do.
     
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  10. f355spider

    f355spider F1 World Champ
    Owner Rossa Subscribed

    May 29, 2001
    17,913
    USA
    #10 f355spider, Feb 18, 2019
    Last edited: Feb 18, 2019
    I had a failure of the wiring to the little Pierburg vacuum valve that operates the bypass valve. This caused the valve to always be closed (oem valve at the time, not Capristo). I was on a trip multiday trip and it was not until the second or third day that the CE light was finally tripped. I forget the exact code, but it was related to a non functioning bypass valve. I quickly found the cause (a wire to one of the pins on the Bosch connector to the valve had come loose) crimped a new connector on and cleared the code. It is possible I am recalling this incident incorrectly, as it was 8 or 9 years ago. But I believe it to be correct, and there were many stops on this trip, so it obviously took many times for the Motronic to see the problem before it finally triggered a fault.
     

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