97 355 Throttle bodies tuning | FerrariChat
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97 355 Throttle bodies tuning

Discussion in '348/355' started by BadHorsie, Aug 7, 2006.

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  1. BadHorsie

    BadHorsie Karting

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    Steven Verwer
    #1 BadHorsie, Aug 7, 2006
    Has anyone ever posted a DIY on syncronising the throttle plates? A mechanic that I talked to last week seemed to think that they should be done yearly. Sounds like its a great way to keep a good throttle responce. I have read some posts on this forum but no definitive proceedures outlined. If someone could email or post a page out of the manual or a link it would be greatly appreciated. Who sells manuals? (trusted source) Comments on this issue? Difficulty rating?
    Thanks
    Steven
     
  2. J.P.Sarti

    J.P.Sarti Guest

    May 23, 2005
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    #2 J.P.Sarti, Aug 8, 2006
    a good cleaning makes sense yearly such as blasting them with intake cleaner but getting them tuned yearly seems excessive.

    I would think the procedure would be similar to tuning a motorcycle via manometers which should come with good instructions on the procedure, first of course the throttle plates should be lined up properly and in sync with the linkages and so forth. A 4 gas analyzer would help as well.
     
  3. BadHorsie

    BadHorsie Karting

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    #3 BadHorsie, Aug 8, 2006
    I thought yearly seemed excessive myself but then thought that maybe normal running could knock them out of sync just from vibration. From what I've read even very small adjustments can have an effect. I think my best move should be to take it to the dealer and see what the results are and if it is noticable I will pursue this further as a DIY. I mean is there any better day spent then fine tuning the Fcar? Hmmm not too much feedback I'm wondering if its because I'm not subscribed?? Does membership have its priveledge?
    Thanks
     
  4. J.P.Sarti

    J.P.Sarti Guest

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    #4 J.P.Sarti, Aug 8, 2006

    No I don't think anyone here has tried it, most 355s have been dealer serviced as they are a bit more complicated than older models with their multiple throttle body set up.

    You could be right concerning the small vibrations and things getting out of tune but a clear result of that is the sticky throttle issue IMO with the 355 as their was a thread on it awhile back.

    Perhaps the factory wsm has the correct procedure but as usual it would be with Ferrari specific tools. I think the manometers would give agood indication if all the cylinders are in sync and you could adjust the air bleeds from there to match similar to a multi carb sync.

    FWIW I have seen copies of factory 355 manuals on Ebay cheap
     
  5. eric355

    eric355 Formula 3
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    #5 eric355, Aug 9, 2006
    Last edited by a moderator: Sep 7, 2017
  6. J.P.Sarti

    J.P.Sarti Guest

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    #6 J.P.Sarti, Aug 9, 2006

    Cool,

    Thanks for posting it
     
  7. BadHorsie

    BadHorsie Karting

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    #7 BadHorsie, Aug 9, 2006
    Just what I was after Eric355! Thank You. Even though I don't have some of the test equipment mentioned I will look into substitutes to complete the task correctly. As an example my OBD II program can maybe detail some of the information that I'm looking for. A little more research on my part for sure. We'll see. Big Thanks Gentlemen.
     
  8. eric355

    eric355 Formula 3
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    #8 eric355, Aug 10, 2006
    A lot of information in the wsm and very interesting to read. IMO a must that every 355 owner should have. Easy to find and cheap, have a look to ebay ...
    For what concern throttle tuning, yes your OBD program must be used, but only to read the idle rpm. The most important equipment is the mercury columns (8 is top, 2 is a minimum !!), or equivalent, to check that vacuum is balanced between each throttle butterfly at idle, but also that vacuum progression is also balanced at throttle openning.
    Not an easy task to perform considering the poor access to all the adjusting screws and while the engine is running. Interesting anyway ...
    Good luck
     
  9. billyfitness

    billyfitness Formula Junior

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    #9 billyfitness, Aug 10, 2006
    This is a great idea to have done at a 30K service, (mine's in right now), especially when getting the cams dialed in...it only makes sense.
    Thanks for the heads up and detail.
     
  10. BadHorsie

    BadHorsie Karting

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    #10 BadHorsie, Aug 10, 2006
    I got a pm and will be ordering my wsm soon. My 4 bank mercury columns are on the way. I was also considering the digital monometer but I can't find one with multiple reads Thanks again.
     
  11. jm3

    jm3 F1 Rookie

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    #11 jm3, Aug 14, 2006
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    Question about Number 5 in this illustration, the actual ports to the throttle bodies. Are these supposed to have plugs over them when not being used?
    Image Unavailable, Please Login
     
  12. eric355

    eric355 Formula 3
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    #12 eric355, Aug 14, 2006
    No, there is no plug on the bodies ports when not used. As for brake bleeding screws, once fully torqued they ensure the tightness. Before to perform any measurement you have to unscrew them a little bit.
     
  13. jm3

    jm3 F1 Rookie

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    #13 jm3, Aug 14, 2006
    Thanks, The manual doesnt really mention that.

    I suppose actually, that if a mechanic were to forget to retighten them, there would be airleaks that could cause headaches.

    Jay
     

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