F355 Secondary air injection shut off valve opening pressure | Page 2 | FerrariChat

F355 Secondary air injection shut off valve opening pressure

Discussion in '348/355' started by salbrech, Dec 27, 2016.

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  1. Dave rocks

    Dave rocks F1 World Champ
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    Nov 23, 2012
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    Dave Lelonek
    Well John - see this is actually a pretty good thread as I now understand some parts of the system that I did not prior :D

    "I care" ;)

    Sorry buddy, I could not resist :)
     
  2. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
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    Brian Crall
    No its not. It is someone who insists the system is broken because he has not bothered to figure it out and wants to reengineer it. In the process wants to argue about it.
     
  3. INTMD8

    INTMD8 F1 Veteran
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    Jun 10, 2007
    6,813
    Lake Villa IL
    Gotcha. Didn't know the vacuum at the manifold was great enough to draw through the check valves without a shutoff valve. Thx
     
  4. Dave rocks

    Dave rocks F1 World Champ
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    I learned something and I'm happy about that - that is all :)
     
  5. johnk...

    johnk... F1 World Champ
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    #30 johnk..., Feb 16, 2017
    Last edited: Feb 16, 2017
    Dave, as Brian has pointed out, the check valve prevents hot exhaust from blowing back into the blower. But if there is a momentary vacuum in the header, as can happen with propagating acoustic waves, the check valve does not prevent air from being through the pump and into the exhaust. The line must be sealed either before the pump inlet or after the pump discharge, which ever is more convenient, to prevent this. If I were designing the system I would place the shut off valve on the discharge side, but there may be reasons unbeknown to me, as to why it might be place on the inlet side. I haven't bothered much with this thread, haven't looked at the diagram, so I don't know, or care (;)), where it is actually located. Just not important to me. The system works as it should or it doesn't. Not a big deal. And it only functions when the car is in open loop mode AFAIK.
     
  6. INTMD8

    INTMD8 F1 Veteran
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    The shutoff valve is on the discharge side of the pump.
     
  7. johnk...

    johnk... F1 World Champ
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    Well there you go. :)

    And what's with the dam site sticking scrip in the middle of posts these days? Had to edit it out.
     
  8. Dave rocks

    Dave rocks F1 World Champ
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    I just like to learn how all of these systems work so when they don't work, I will have a proper understanding to diagnose them ;)

    I don't like looking into the engine bay and seeing parts that I don't understand the function :)

    It's all very interesting and informative to me.
     
  9. INTMD8

    INTMD8 F1 Veteran
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    Jun 10, 2007
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    Same here.

    I don't think mine works. I've never heard it. Going to pull it off when I replace the cats with straight tube anyway :)
     
  10. Dave rocks

    Dave rocks F1 World Champ
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    It's hard to hear, Jim. I did a video a while back and when I played the video back, I could hear it much better. When at the car, the pitch just could not be heard well (by me anyway)
     
  11. drbob101

    drbob101 F1 Rookie
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    Nov 26, 2012
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    Bob Ferraris
    Mine didn't work and when I unplugged it at the motor, a other in the connector was melted. Replaced the connector and it works. There is an issue with them blowing fuses, etc. as they age. Brian could elaborate but you might start with the fuse and the connector first.
     
  12. Rifledriver

    Rifledriver Three Time F1 World Champ

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    Until the pump starts going south they make very little noise. On OBD2 cars it will set a light.
     
  13. eulk328

    eulk328 F1 Rookie

    Feb 18, 2005
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    #38 eulk328, Feb 16, 2017
    Last edited by a moderator: Sep 7, 2017
  14. tullos3

    tullos3 Rookie

    Oct 13, 2005
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    HUGH
    Yeah, It is...His questions are fair and intelligent. The two minute air injection system is certainly poorly engineered as the pump is often deadheaded against a shut valve, causing failure....period. The EGT controller failed and had to be reengineered. The vacuum reservoir has corrosion issues. The by pass valve rattles predictably. Have you seen the engineering on the exhaust system? Do you replace headers with Ferrari headers or better engineered ones? Why are there so many re-engineered exhaust products? Have you seen the headlight motors fill with water? Do you solve it or just bow to Italy and replace them with the same poorly engineered crap? Ferrari does many things very well and some things very poorly...The build great race cars and are not great at street cars. I have been working on the cars for forty five years. You do realize they built cars for years that would not idle without overheating and would not go 15000 miles without knurling valve guides....and how bout those 355 valves? Those were a feat of engineering, except for the excessive failures...due to poor engineering.
     
  15. Rifledriver

    Rifledriver Three Time F1 World Champ

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    Whatever.
     
  16. Targatime

    Targatime Formula 3

    Feb 22, 2014
    1,460
    Los Angeles
    - OLDE THREAD ALERT -

    My SAI pump is loud. Reading this it apparently should be much quieter. Mine whistles for a few mins after cold start and it's very conspicuous. I care not in the slightest to have a functioning SAI system. I assume if I just unplug the pump I will get a CEL? (5.2 car). Alternatively can these pumps be rebuilt?
     
  17. yelcab

    yelcab F1 World Champ
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    You won't be able to rebuild it, but you can replace it with a more reasonable Lexus / Toyota pump.
     
  18. Laserman

    Laserman Karting

    Oct 26, 2018
    113
    Minneapolis, MN
    yelcab, can you supply us with a Lexus/Toyota pump part number?
     
  19. yelcab

    yelcab F1 World Champ
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