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n75 j valve

Discussion in 'A3/S3 Forum (8L Chassis)' started by s3 man, Mar 8, 2010.

  1. s3 man
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    s3 man Member

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    [Mar 8, 2010]
    Hey guys just wanted to no if anyone has fitted the n75 j valve on there s3?how is this diffrent to the standard n75 valve and what does it do.ive herd that its have most of the vac pipes removed.any performance gains ect?
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  3. golf
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    golf ***** rent boy VCDS Map User

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    [Mar 8, 2010]
    Use the search facility, this has been asked several times before.
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  4. Welly
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    Welly VX220 SC Driver :)

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    [Mar 8, 2010]
    Yes indeedy mate, I have.

    The N75 C/F is the stock item. The J valve is off the 225 TT and produces slightly more boost.

    The N75 valve is the ECU's method of controlling the boost. The way it works is by opening and closing the pipe to the wastegate, allowing boost through to the turbo's actuator as the ECU sees fit.

    It requires no pipework modifications to fit, and is a very easy 2 min job to be honest.

    It made such a difference to my APY engine when I fitted it. Bear in mind that it seems to be OK on the APY 210 engine - however this valve has a habit of bringing limp mode on on other engines for some reason (well - the reason is that it produces more boost and the ECU doesn't likey....).

    Same money from the dealer as the stock item, and IMO, well worth it.
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  5. Mpathe
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    Mpathe 1st gear

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    [Mar 8, 2010]
    think i need to replace mine, welly how much was the n75j thanks
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  6. Andrew@A.L.D
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    Andrew@A.L.D Cylinder Head Master

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    [Mar 8, 2010]
    Mine was £46.73+vat at the time last year ( 15% )

    Part number should be

    P A034 906 283 J
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  7. 1animal1
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    1animal1 The Clar!! it mouves!!! VCDS Map User

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    [Mar 8, 2010]
    ive literally just ordered an N75F today - dealer quoted £75, so i asked my mate to order via his garage account - also £75 :/
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  8. sportstractor
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    sportstractor Chugger

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    [Mar 8, 2010]
    there is a really good post on seatcupra.net about the J valve... http://www.seatcupra.net/forums/showthread.php?t=10170

    The J valve doesnt tend to bring on limp mode alot from what iv read, although the lucky buggers with APY dont have map sensors, so this is probably why it doesnt cause limp mode. Im not sure if it 'allows' more boost, but its slower to open the wastegate? something along those lines. I believe the J valve also has an adjuster, when adjust helps adjust limp mode. Anybody feel free to correct me, but this is what i have read. I wouldnt mind trying one if anybody wants to swap one for an F
    Last edited: Mar 8, 2010
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  9. 1animal1
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    1animal1 The Clar!! it mouves!!! VCDS Map User

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    [Mar 8, 2010]
    i had a convo with Mr Silverstone from JBS/Custom Code who says he hates the N75J's as they play havoc with his maps - never felt the need myself but thats becos im BAM :(
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  10. s3 man
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    s3 man Member

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    [Mar 8, 2010]
    I have a bam to.mayb I shud leave it then.I really can't be doin with limp mode cuz I'm gettin it mapped this week.I fort the n75 j was jus removing the vac pipes.what's the j meen then
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  11. 1animal1
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    1animal1 The Clar!! it mouves!!! VCDS Map User

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    [Mar 8, 2010]
    its the type of valve, internal settings.....its a direct replacement for the existing valve which will be exactly the same, bar the colour
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  12. Welly
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    Welly VX220 SC Driver :)

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    [Mar 8, 2010]
    I believe you're referring to the AGU which doesn't have a map sensor.... The APY most certainly does.....
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  13. Mr.G
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    Mr.G Active Member

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    [Mar 9, 2010]
    Hmm how would one work on an AMK coded engine?
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  14. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Mar 9, 2010]
    TBH, they are a bit russian roulette if they work well on any car... I suspect they will cause more probs on a car fitted with a MAP sensor than they will on earlier cars as the ECU is more aware of whats going.

    If your car is mapped then I wouldn't bother as taking control of things like boost away from the ECU can lead to engine damage at worst or at least limp mode....

    AMK engine code has a MAP sensor btw :)

    <tuffty/>
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  15. fran-s3
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    fran-s3 Active Member VCDS Map User

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    [Mar 9, 2010]
    Mines a AMK and my JValve worked great until is started going into limp mode a week later... Kept losing all boost until I restarted the engine so I sold it and went back to F... (APS remap) I also found it would certainly boost higher initially but tail of early compared to my original F valve... Sold it for as much as I payed for it on Ebay!

    Just my experience with it.
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  16. S3 Rav
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    S3 Rav Well-Known Member

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    [Mar 9, 2010]
    looks like with the amk models its not worth doing anyways
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  17. sportstractor
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    sportstractor Chugger

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    [Mar 9, 2010]
    my mistake:readit:

    for some reason i thought otherwise.

    It is strange how they work for a little while then start playing up.
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