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boost leak/command pressure

Discussion in 'A3/S3 Forum (8L Chassis)' started by Freek, Mar 13, 2014.

  1. Freek
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    Freek New Member

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    [Mar 13, 2014]
    Hi guys, i've used the search function but didn't get the answer i was looking for.
    my car; S3 2000 APY engine,it has an FMIC an B5 TIP and is tuned stage 1 here in Belgium (370Nm/260BHP)
    when i got it the DV was faulty (did not realise at that point) i was getting a lot of flutter.
    Now fitted a forge 007p with green spring.
    fitted liquid gauge and did some testing, boost rises slowly to max 18psi then holding 16 psi.
    i don't seem to have a boostspike, so i suspected a leak, changed upper boost pipes, N249 delete, PCV delete/ catch can...
    then logged cmd/ actual boost on the liquid, both are about the same, max 18PSI at +-4000rpm.
    the Torque is 300NM (290 is standard) bhp is 260 (210 standard)

    Schouldn't the command boost be higher if i still had a boost leak somewhere, what else could be faulty?
    it has a new MAF, new plugs and coils are going in tomorrow.
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  3. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Mar 13, 2014]
    Wastegate maybe the issue if its slow to spool... check the preload


    <tuffty/>
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  4. badger5
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    badger5 www.badger5.co.uk Site Sponsor

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    [Mar 13, 2014]
    looking at logs of boost to try and determin boost leak is borderline pointless.

    find someone with a smoke machine to smoke test for leaks

    it will cut to the chase quickly and reveal any leaks
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  5. Freek
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    Freek New Member

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    [Mar 13, 2014]
    i will search someone with a smoke tester in Belgium.
    But i pretty much changed all the hoses and clamps so i wondered iff there could be another cause. Someone on vwvortex mentionned the sparkplugs too. changing that tomorrow . And will check the wastegate preload when i get it up a ramp.
    Another question, i read the forge 007p is ok with the green spring and 1 shim. What is the thickness of those shims, i would make one myself at worK.
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  6. badger5
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    badger5 www.badger5.co.uk Site Sponsor

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    [Mar 14, 2014]
    new forge DV? one with a rubber seal piston? green should work fine
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  7. Freek
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    Freek New Member

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    [Mar 14, 2014]
    Yes, it's the new one with rubber seal.
    I also have the B5 TIP on my left hand drive car. What would be the best way to bend my brake lines from the master brake cilinder?
    I'm afraid to kink them. I do get good airflow, about 202g/s so i don't know if the TIP being pushed by the lines affects flow much?
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  8. badger5
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    badger5 www.badger5.co.uk Site Sponsor

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    [Mar 14, 2014]
    pictures?
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  9. Freek
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    Freek New Member

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  10. Freek
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    Freek New Member

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    [Mar 15, 2014]
    i took it off today and found there was no sealant on the billet adapter, it was really loose.
    this is a picture of the TIP out of the car, i can already feel it's getting weaker where it is rubbing the brake lines.
    I will bend the lines as far as i can/dare.
    20140315_114758.jpg
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  11. Freek
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    Freek New Member

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    [Mar 24, 2014]
    so, i reset the preload on the actuator to 3 full turns, still no change.
    I disconnected N75 electrical and now i'm seeing boost creep, hitting 7psi then creeping to11psi.
    then i checked the wastegate cracking pressure, it opens at the lowest reading on my gauge (+-3psi) i then put some more preload.
    Nothing changed. how far can i go with the the preload? When i pull the actuator rod by hand i feel spring tension.
    Can i continu to increase preload or do i have to change the actuator?
    when the previous owner had the car mapped it had emptied out Cats fitted, now the Original ones are on for the MOT. Can this by the source of the boost creep?
    slowly learning how these engines work after loads of reading and time under the hood.
    #10

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