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manual boost controller and de-wiper question

Discussion in 'A3/S3 Forum (8L Chassis)' started by jay1601, Jan 22, 2011.

  1. jay1601
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    jay1601 Well-Known Member

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    what is people thought on manual boost controllers ? thinking of fitting one to my car, as i'm fed up of it boosting at 3/4PSI. can't find any leaks and no faults codes. just wanting it to run at 9/10PSI again.

    and my second question is, where do people buy grommets when they hae de-wipered. tried lots of different places. can't find anywhere that sells big enough ones. i measured the hole to be 27mm. biggest i got was from halfords that was 25mm, i think it need to be a little bit bigger

    thanks for any help Jay
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  2. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator

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    if your not making the correct boost, theres a problem.

    Bodging it with an MBC isnt the solution, fixing the problem is.
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  3. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    If your turbo is only producing 3/4 psi then you still have a problem and should continue to look to fix it... One test I have used in the past with great caution is to remove the pipe from the N75 to the actuator and take the car for a quick skirt up the road... if the boost goes quite high (as it should if all was good) then you have a leak or the ECU is going into limp mode for whatever reason... if the boost remains low then your turbo is very tired and needs replacing... K03's suffer from wear and expire quite regularly... seen loads of Ibizas with tired turbos...

    DON'T run the engine longer than a quick spurt to see if the boost is there as this WILL end in tears if you abuse this.. as soon as you see the boost rise above 10/15psi then back off and then put the pipe back on...

    In my experience, if you have no boost or vac leaks, no fault codes and logging MAF, boost request etc show everything is as it should be then the turbo is normally the reason... the blades curl over too which is a fairly good sign the turbo has had it..

    Depending on the year of your car then an MBC will be of no use anyway as the facelights use a more modern ECU that throw a hissy the minute you try and give it more boost than it wants too...

    <tuffty/>
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  4. jay1601
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    jay1601 Well-Known Member

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    My car is a 1999 AGU block. I have taken the pipe off going from the N75 to the wastegate, it will boost 15+ with no problems

    I have pressure tested the engine. Found 1 leak in the FMIC set. Up, was fixed. Still didn't fix the problem. Only thing I haven't done is VAG-COM. As I don't have it

    Was thinking it could be a dodgy N75 vavle?
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  5. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    N75 will throw a fault code if electrically faulty and will just run actuator pressure if mechanically faulty so its plausible that the N75 could be the problem... I would be tempted to 'borrow' one to try first as they are not that cheap if its not the problem...

    You can log N75 duty cycle (block 118) to see if the ECU is trying to use the N75.. duty cycle will hit 100% on initial spool to get the turbo going but will settle down... if there is little or no activity (can't remember what it does in limp) then the ECU is holding back for some reason..

    Logging block 115 will give boost request so you can keep an eye on that along with N75 duty cycle to give you an idea of if the ECU is actually asking for the boost rather than not...

    Logging block 002 will give you airflow too... log them all together 002, 115 and 118 and you will have a picture of whats going on boost wise so you can work out where to go next...

    <tuffty/>
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  6. Stanley
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    Stanley Member

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    I ran with a bypassed N75 for a whole evening and it was fine. Went like stink too! haha.

    Give it a whirl!
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  7. coyle
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    coyle From Show... to GO

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    not a great idea lol.
    can end in trouble if it boosts too high
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  8. jay1601
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    jay1601 Well-Known Member

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    I don't want to bypass it fully. Only want to gain 5/6 PSI

    Would rather do ot right, just I can't find what's wrong with the bloc, need to find someone that I can either borrow a N75 from or can find someone to log my engine for me
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  9. Sandip
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    Sandip Well-Known Member

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  10. ScottD3
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    ScottD3 I want your faulty electronics

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