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Glowing Turbo. Bad news ?

Discussion in 'A3/S3 Forum (8L Chassis)' started by s3bow, Apr 28, 2005.

  1. s3bow
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    s3bow Member

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    Hi all, been playing with the map in my S3 and TBH is a lot better than it was. Reaches about 1.4 bar maximum, so I thought I'd adjust the actuator. Moved it in about four turns of the nut. Has much stronger mid range now but I think its lost a little at higher revs. Turbo is working quite hard and after a blast tonight for about 1.5-2 miles, flat out, the turbo and manifold were glowing bright orange.
    Is this a bit on the dangerous side, should I back it off a bit ? I'd expect it after a sustained blast, i.e 4-5 miles, but 2 ?
    Anyone had experience of this ?

    Chris.
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  2. Markb
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    Markb Active Member

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    Mine glows red after I've been giving mine some boot and that is standard. So I wouldn't worry.

    You would probably benefit from an uprated intercooler though.
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  3. god_thats_quick
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    god_thats_quick Numptie of the highest order

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    I remember seeing a glow from around the turbo on my standard S3 after a long drive, don't think you even need to be going for it!
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  4. s3bow
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    s3bow Member

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    This was a blatt for about 2 miles. Was driving it very very hard though.
    Coming hard on boost at about 3500. Maybe turbo is working a bit too hard.
    Rich, Glen ? Advice appreciated.

    Chris.
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  5. Ess_Three
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    Ess_Three Active Member

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    Even running 1.8+ bar peak boost, mine only used to get a red glow out on the road...on the rollers it would go so orange i'm sure I could see the shaft through the casting!

    Personally, I'd be very wary of playing with the actuator rod length without doing some accurate measurememt of boost pressures, EGTs, A/F ratios etc...meaning a rolling road play about...
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  6. PaulRS3
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    PaulRS3 Active Member

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    im with Glen on this one.

    Playing with the actuator rod is not the way to do it,

    A remap, is the way.

    The N75 valve is the valve that regulates the wastegate, its just a matter of remapping that to suit.


    Im sure i read that Audi dont touch the actuator at all, if anything comes loose or breaks, the replace the whole turbo assembly, as they come pre set.
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  7. RichA3Turbo
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    RichA3Turbo ...Watching you! Staff Member Moderator

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    Agreed... Asking for trouble is you ask me. It may well give you more power, but with logging AFR, boost .etc i would leave it well alone...a remap is by far the safest way of setting up the car.

    RIch
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  8. s3bow
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    s3bow Member

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    The same map was used on a LCR and got 1.5 bar peak and about 1.2 at around 6000rpm.
    Mine can only make 1.4 and 1.0 at 6000. Thought maybe this would help me hold it.
    Have turned it back out half of what I turned it in as the turbo was getting way too hot.
    Why do you think I can't sustain the boost ? Air leak ?

    Chris.
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  9. imported_highlander1
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    imported_highlander1 Guest

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  10. djjnrj
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    djjnrj Guest

    i think you're 'loosing' boost because of the turbo on the S3. in standard form the S3's blower is excellent at lower and middle revs, but the small turbine wheel makes it difficult for the turbo to produce good boost figures at higher revs. i may be wrong.
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  11. s3bow
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    s3bow Member

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    Mates LCR produces constant 1.6 bar
    and the same code as mine in another LCR reaches 1.5.
    Don't think its a K04 thing, just my K04.
    Anyone think I should try a different N75 ?

    Chris.
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  12. Ess_Three
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    Ess_Three Active Member

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    [ QUOTE ]
    Mates LCR produces constant 1.6 bar
    and the same code as mine in another LCR reaches 1.5.
    Don't think its a K04 thing, just my K04.


    [/ QUOTE ]

    Constant 1.6 bar?
    Where?

    1.6 bar at the red line?
    I just can't see that...

    Or do you mean it constantly produces 1.6 bar peak...each time?

    The K04 can make big peak boost, but simply cannot produce big boost further up the rev range...the compressor is simply too small. Even if you rag the turbo to death, using re-maps, N75s, boost machines etc you still strugle to maintain 1.2+ bar at the top of the rev range.

    Certainly on standard ICs you can't run it there...the turbo gets so damn hot, the inlet charge temperature goes through the roof and the ECU retards the timing to protect the engine - making the engine loose performance. Not ideal.

    With modified turbo pipework, 2 x efficient ICs (including a FMIC), Samco Hoses, aggressive re-map and N75 you will struggle to get more than 1.2 to 1.3 bar held to peak power - and the K04 is absolutely flat out at that - way outside it's afficiency range.


    [ QUOTE ]

    Anyone think I should try a different N75 ?


    [/ QUOTE ]

    Without logging EGTs, Inlet charge temps, IC efficiency, Timing, AF ratio etc...no I don't think you should try it.

    But, log all the pertinent parameters on a decent rolling road and convince yourself it's not going to damage the engine, and prove that you are getting a gain...fine, by all means try a different N75.

    But, you still may not be able to run an alternative N75 out on the road...it all depends on whether the limp mode activation point has been raised, or not.
    If it hasn't - or hasn't been raised enough - you hit limp mode out on the road.

    Changing the N75 on a re-mapped engine is not the best idea unless you are aware of what it's doing, and if your engine is able to cope. Just be wary.
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  13. s3bow
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    s3bow Member

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    Sorry, that was confusing of me.
    What I meant to say was a peak figure of 1.6 consistantly. Both the LCRs have 1.2 at @6000 , whereas mine can only keep 1.0 bar. Same map in all.
    What are the alternative N75s ?

    Chris.
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  14. Ess_Three
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    Ess_Three Active Member

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    [ QUOTE ]
    What are the alternative N75s ?



    [/ QUOTE ]

    The 'H' or the 'J' - both being reffered to by the suffix on the part number.
    #14
  15. s3bow
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    s3bow Member

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    And the difference between these two is what ?

    Chris.
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