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N249 Bypass How To (2000 S3 - but same for many)

Discussion in 'General Technical / How To' started by Welly, Dec 3, 2009.

  1. s3 toe
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    s3 toe Member

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    [Feb 18, 2011]
    I put my old bailey dv30 this way and ended up spliting a pipe on full boost the turbo screams like a strangled budgie now. Gauge is still reading 1.4 but you can feel it lagging unless you either feather in the turbo or plant it and lift halfway off, the pressure does drop to a bar of boost but you can feel her pick up again. Just noticed laat night after doing the by pass ive lost 2 psi now have i done something rong.
    #41
  2. s3 toe
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    s3 toe Member

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    [Feb 18, 2011]
    I put my old bailey dv30 this way and ended up spliting a pipe on full boost the turbo screams like a strangled budgie now. Gauge is still reading 1.4 but you can feel it lagging unless you either feather in the turbo or plant it and lift halfway off, the pressure does drop to a bar of boost but you can feel her pick up again. Just noticed laat night after doing the by pass ive lost 2 psi now have i done something rong.
    #42
  3. sam4191
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    sam4191 If In doubt, Flat out!

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    [Feb 27, 2011]
    Thanks very much for this Welly!!! Just done it on my car... feels more responsive! Sounds better too! Feels quicker, but not sure that it's just the placibo effect or not!! lol!

    Cheers
    Sam
    #43
  4. rhubarb4
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    rhubarb4 Certified Jardo Slayer

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    [May 22, 2011]
    Ok maybe im being a bit thick here but I have AMK engine S3, if not needing the T-piece I run a single piece of pipe from the DV valve to N249, then from the N249 to where please, and what happens to that Vac feed from inlet pipe that you cut Where does it go or come from and do I have to change or take it out where do I put that if I havent got one of those n112 valves.

    Sorry if its obvious I just cant see it
    Last edited: May 22, 2011
    #44
  5. S3Lol
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    S3Lol Member

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    [May 22, 2011]
    im looking at doing this next weekend while I do the TIP and jetex. Will 1 meter of 4mm vac hose will suffice or do I need more??
    #45
  6. Welly
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    Welly VX220 SC Driver :)

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    [May 22, 2011]
    The AMK is very easy to do. As you said, you don't have the N112 valve for the SAI, so all you need to do is run a vac hose from the inlet manifold direct to the DV.

    Same principle, but just a straight pipe from the inlet mani nipple to the top of the DV.
    #46
  7. Welly
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    Welly VX220 SC Driver :)

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    [May 22, 2011]
    Depends on the engine....
    #47
  8. 5ean
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    5ean S3 Owner VCDS Map User

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    [May 26, 2011]
    Welly, from your comment 2 above, am i right in saying for the AMK engine there is no T piece needed then? Just 4mm vac hose direct from the inlet mani to the DV? Do any other pipes need blocked off etc?
    #48
  9. Welly
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    Welly VX220 SC Driver :)

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    [May 26, 2011]
    Nope, no blocking required. The only thing you are doing is bypassing the N249 mess.

    When removing all those hoses, you just take them out of the equation. All the DV needs is a vac source from the inlet manifold, so one pipe from the inlet mani to the DV is fine.

    Simples.
    #49
  10. 5ean
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    5ean S3 Owner VCDS Map User

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    [May 26, 2011]
    So once I've done that I can pull all the N249 **** out yeah? Or will the ecu throw a wobbly?
    #50
  11. Welly
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    Welly VX220 SC Driver :)

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    [May 26, 2011]
    Yes, but disconnect the valve from the pipes and leave the valve there. That will keep the ECU happy.
    #51
  12. Syvo
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    Syvo IF IN DOUBT GO FLAT OUT

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    [May 26, 2011]
    so how would this work on an ARY engine same as the TT i looked on the mkivs forum and they have just took the pipe from the top of the dv and tee'd into the fpr job done would this be right.

    its the mkivs link you put up welly think its on the things to do for free thread will find it a paste it in ere
    #52
  13. Syvo
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    Syvo IF IN DOUBT GO FLAT OUT

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  14. Welly
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    Welly VX220 SC Driver :)

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    [May 26, 2011]
    I wouldn't be teeing into the FPR line personally.

    Firstly, that leaves you with a nipple on the inlet manifold which is useless.

    Secondly, I discourage anyone from teeing into the FPR vac line because it increases to potential for leaks. The FPR on the 1.8T is rising rate. If you have a leak in the vac/boost line to the FPR, you won't be getting the correct amount of fuel. Which is bad. Very bad.

    Up to you ultimately, however it's not something I would do.
    #54
  15. Syvo
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    Syvo IF IN DOUBT GO FLAT OUT

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    [May 26, 2011]
    so should i go off the top of the dv and go into the spare nipple on the inlet as i have fitted a catch can so the nipple behind the dip stick is pluged and i have also pluged the other nipple as my pcv valve conected to both i also have a pipe which comes from the tip which conected to the nipple on the inlet i blocked this off as was unsure to put to the nipple on the inlet.

    as shown in pic. (its the pipe next to the red circle that follows the fpr line.

    [​IMG]

    so if it conected the pipe from the top of the dv would i then tee the pipe for the tip into that and conect into the spare nipple?

    also i have the boost guage in the fpr at the mo so if i did the above would i then tee into the same line and use this for the boost guage?
    #55
  16. Syvo
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    Syvo IF IN DOUBT GO FLAT OUT

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    [May 26, 2011]
    i only have two nipple on the inlet manifold 1 behind the dip stick and one right next to that one my engine code is ARY
    #56
  17. Welly
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    Welly VX220 SC Driver :)

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    [May 26, 2011]
    In which case, I guess you don't have much choice dude.
    #57
  18. Syvo
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    Syvo IF IN DOUBT GO FLAT OUT

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    [May 26, 2011]
    the nipple to the right hand side of the one behind the dipstick is free so could i tee the spare pipe coming from the tip into the pipe coming from the top of the dv and conect into this spare nipple.

    then could i tee into the pipe coming from the dv and use this for my boost guage instead of the fpr.

    i hope this makes sense
    #58
  19. Welly
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    Welly VX220 SC Driver :)

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    [May 26, 2011]
    That sounds like the best plan to me dude if I'm honest.
    #59
  20. Syvo
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    Syvo IF IN DOUBT GO FLAT OUT

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    [May 26, 2011]
    ok will do that at the weekend think ive got about a meter of tubing so may just do atch will go awesome and get some more tubing winner. cheers for the help welly hows the car with the new turbo bet some people are looking at ya funny when you just breeze past them when they trying to race ya lol
    #60
  21. Welly
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    Welly VX220 SC Driver :)

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    [May 26, 2011]
    My mate in his 172 Cup Clio (tuned to 198 BHP - goes like stink) came up along side me, then I waved and buried it and disappeared.

    He refuses to come out in the S3 for fear of his life.

    Pussy. lol.
    #61
  22. Syvo
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    Syvo IF IN DOUBT GO FLAT OUT

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    [May 26, 2011]
    lmao a m8 of mine used to have a evo 5 that was running 450bhp thats was very scary as he used to brake at last minute he had the standard brembo calipers but the discs and pads were epic they would stop the car on a 10p.

    that used to scare the **** out of me that was untill i got behind the wheel of a gt3 from me bro's work that was a track slag and had been tuned to death think its was around 6-700 bhp omg i couldnt get out of the first two gears driving it about as it was just that fast and on r888 that thing was an animal around the streets and track.

    it allways makes me want to do what you have done to urs but its just money 350-400bhp in mine i dont think i would ever sell it but pricing things up i dont know how you afford it mate it would be mega £££££ for me to get mine any where near urs
    #62
  23. rhubarb4
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    rhubarb4 Certified Jardo Slayer

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    [May 26, 2011]
    Thanks Welly:applaus:, even me being a trained chimp have done it lol only took 20mins, bonus:arco:. Oh and a sore thumb due to spring going under my nail :sob:

    Cheers, Chris.
    #63
  24. 5ean
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    5ean S3 Owner VCDS Map User

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    [Jun 1, 2011]
    Just had a look at doing this and its baffled me again :( I can see what needs to be done, but how do i get to the underside of the manifold where the vac hose plugs in to? Also, how do i get that silly little clips off? There's nowhere near enough room to get in about with hands to pull the pipe off nevermind putting a new clip back on!
    #64
  25. Welly
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    Welly VX220 SC Driver :)

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    [Jun 1, 2011]
    What engine mate?
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  26. 5ean
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    5ean S3 Owner VCDS Map User

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    [Jun 1, 2011]
    AMK.. I know its a straight hose from the dv to the inlet mani but the hose is directly under the mani by the looks of it and impossible to get to?
    #66
  27. Welly
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    Welly VX220 SC Driver :)

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    [Jun 1, 2011]
    Nothing is impossible mate, it's tight I admit, but it can be done.....
    #67
  28. 5ean
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    5ean S3 Owner VCDS Map User

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    [Jun 1, 2011]
    Anyone in the Aberdeen region who has done this fancy some beer token for half an hours work?? :)
    #68
  29. S3Lol
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    S3Lol Member

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    [Jun 9, 2011]
    do you need any clips to secure the hose or can you push on and thats fine?
    #69
  30. Jordysport
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    Jordysport Member

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    [Oct 15, 2011]
    so with the AMK you run a pipe from the Inlet mani to the DV and then just disconnect all the rest of the malarky and the N249 with no pipes connected just plugged in tucked away somewhere??? [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    #70
  31. stumpy83
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    stumpy83 one legged wonder

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    [Jan 5, 2012]
    may be a silly question but does this work with the agu engine?
    #71
  32. Welly
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    Welly VX220 SC Driver :)

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    [Jan 6, 2012]
    No, there isnt an N249 on the agu.
    #72
  33. stumpy83
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    stumpy83 one legged wonder

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    [Jan 6, 2012]
    thanks mate ;)

    has any one made a how to guide onb removing the charcoal filter please, ?
    #73
  34. Welly
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    Welly VX220 SC Driver :)

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    [Jan 6, 2012]
    Not a guide per se, but I did show how to do it in my hybrid build thread. I'll have a look for it now.
    #74
  35. Welly
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    Welly VX220 SC Driver :)

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    [Jan 6, 2012]
    #75
  36. stumpy83
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    stumpy83 one legged wonder

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    [Jan 6, 2012]
    thanks mate ;)
    #76
  37. fallsy83
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    fallsy83 New Member

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    [Jan 16, 2012]
    forgive me if im being a muppet, i want to bypass the N249 mess as my 2002 BAM s3 is throwing up fault code 17608 N249-bypass valve mechanical malfunction, and binning boost. looking at the hoses, the hose going into the underside of my inlet mani is smaller than the hose going into the top of my DV so how do i run a hose from the inlet mani to the DV
    #77
  38. fallsy83
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    fallsy83 New Member

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    [Jan 16, 2012]
    forgive me if im being stupid but looking at my BAM engine bay the hose coming up from inlet mani is smaller than the hose into the top of the DV so how do i run one hose if the hoses on here are different sizes?
    #78
  39. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Apr 10, 2012]
    Just had a quick read through this but cant find any pics or info from anyone who'd wired in a resistor instead of refitting the N249 valve. I've got nowhere to fit it as I've removed my hanging bracket.
    #79
  40. Welly
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    Welly VX220 SC Driver :)

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    [Apr 10, 2012]
    Extend the wiring and cable tie it elsewhere mate - resistors are not good practice IMHO. They get hot and cause problems.
    #80

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