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Strange performance characteristics

Discussion in 'A3/S3/Sportback (8P Chassis)' started by warren_S5, Aug 20, 2009.

  1. warren_S5
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    warren_S5 Moderator Staff Member Moderator

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    Went out in the car tonight, and straight away it felt slightly odd.

    When spooling up from low revs (when planting your foot quite hard) the car seems to surge almost too hard. Almost if its over boosting.

    If you are doing 50-60mph in 6th and floor it by comparison you don't seem to get anything like the surge I used to. However if I drop a gear it is quite a bit better, but somewhat inconsistent. Seems to be no issue with getting to high speeds, and no apparent misfires etc...

    Only other thing I have noticed is a fluttery sound coming from the drivers footwell.

    Aiming to get the car on VAGCOM tomorrow, but any thoughts from anyone as to what is sounds like.

    Car is running 98RON, not long serviced, and a new revision OEM DV, so don't see these as an issue. Could it be MAF related?

    Many thanks in advance.
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  2. Staz
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    Staz is a retronaut Staff Member Moderator

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    How long ago was the DV fitted? Does it have the 2 springs like on the Forge IIRC?
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  3. warren_S5
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    warren_S5 Moderator Staff Member Moderator

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    It's the revision OEM VAG DV, and it was fitted about......2 months ago I guess. It's the one without the rubber seal which was designed to overcome tearing of the diaphragm.
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  4. voorhees
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    voorhees Moderator Staff Member Moderator

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    warren your not getting me to want to buy a newer S3 one little bit :)
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  5. Staz
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    Staz is a retronaut Staff Member Moderator

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    So there's no opening it up it's just fit it and go?

    2 months would be a bit weird too.

    Dunno then mate sorry.
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  6. warren_S5
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    warren_S5 Moderator Staff Member Moderator

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    It's not all fun and big bills you know. Like anything great it has a playful side which likes to keep you guessing.

    Off to Storm Developments at lunchtime to get some logs done on the car whilst its running.

    Will report back.

    N75 valve used to provide similar feeling on the Leon, but I have got another DV to swap in if it proves to be defective.
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  7. Spin140
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    Spin140 Active Member

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    I bet they try and sell you a new intake and full exhaust system, if in doubt sell up !!

    Hope you get it sorted mate.
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  8. S3Alex
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    S3Alex Rarely neutral

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    Hope it all gets sorted out.

    The problems with mine seem to have been dealt with after finally fitting a CAI,and I think the misfire was probably due to airflow limitation through the stock intake.
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  9. warren_S5
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    warren_S5 Moderator Staff Member Moderator

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    I may have the air intake limitations sorted by 26th August. Watch this space :icon_thumright:

    I went to uni / house shared in Oxford with the guys from Storm Development, so they won't be pressure selling at me!

    Here is a picture of us all fitting a replacement GTi 16v KR engine into my Mk2 Jetta back in 1997 in student digs (me left, Miles middle, Andy front)

    [​IMG]

    Those were the days when the house stank of paraffin and the hallway was full of car parts!

    Marriage has sanitized our new house, there is a set of 18" S3 alloys in the utility room and some HPFP internals on the shelf in the lounge, otherwise it's a show home!
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  10. S3Alex
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    S3Alex Rarely neutral

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    :)Definitely a student house there Warren...I like the way the garage is literally full from floor to ceiling.

    At least yours was full of useful things.....:)
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  11. warren_S5
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    warren_S5 Moderator Staff Member Moderator

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    UPDATE:

    Well having had my car on VAGCOM there are (as you may expect) no error codes.

    There does seem to be some surging issues when the car spools up, and these may be coming from one of two areas (air intake restrictions from running standard engine cover OR OEM exhaust cats restricting gas outputs to the rear).

    We ran the car on the road with VAGCOM and as it was a hot afternoon (25 deg C) we noted the timing was dialling back to -4.0 / -3.8 under full load robbing quite a significant amount of power once intake temps were rising.

    We are going to fit a spray bar onto the intercooler in the next couple of weeks (from a Subaru Impreza), and next week I am going to see a man in the know about air filters to mock up a CAI.

    The exhaust for now will just have to wait, but I will have to fit new plugs and clean up the coil packs.

    I did notice when sat at standby if you rev the car, as it backs of it's popping quite a bit more than it used to as unburnt fuel gets chucked out through the exhaust system. I do wonder what effect this may have on the cats, and how long the system may last.

    We came to a conclusion at about 8pm that night that I am wasting my time chasing dreams with these little tubby lumps. I went out in Andy's 911 Carrera 4S and I think I am now pretty much convinced that at some point next year I will sell the S3 and get a second hand 911 or M3 CSL. I'm getting VERY tired of running round in circles trying to get the performance out of a small engined turbo, and the only way to get consistent power is to get a decent capacity engine to start with pushing 350bhp+. I will then get it supercharged and leave it at that. I'm pouring good money after bad down the drain trying to chase short lived dreams that don't last here.
    Last edited: Aug 24, 2009
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  12. S3Alex
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    S3Alex Rarely neutral

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    There's a lot of 911's around at very good prices currently,and a friend of mine at work has just bought himself a lovely 996 in superb condition,for not a lot over £20k with FSH and one lady owner,from a Porsche dealer.

    Well worth looking if that's the course you're considering,although your problems may well be sorted with a matched intake and exhaust,as mine were.
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  13. Iggu
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    Iggu Active Member

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    Warren - surely the first thought has to be that you are running Revo Stage 2+ without the recommended engine parts. I know Carl at Revo has said that you theoretically can run Stage 2+ without a full CAI and TBE but he has also said that this is not Revo's advice nor how the system was tested.

    It just sounds to me that the Carbonio (which is no more air efficient than the OEM system) cannot get enough air in to match the upgraded fuel pump's capacity and what the map is demanding.
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  14. AuldReekie
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    AuldReekie Member

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    I am deliberately skipping the real issue at hand to say: get the CSL. :yes: (Just so I can mooch a cabby in it)
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  15. S3Alex
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    S3Alex Rarely neutral

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    This does seem to fit in with the problems I was having,as I've already said,and whilst trying to keep the engine looking stock is very useful for the warranty,it doesn't seem to suit the needs of the Stage2+ mapping and HPFP.
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  16. warren_S5
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    warren_S5 Moderator Staff Member Moderator

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    I see what you're all saying, and whilst I admit that the exhaust / filter scenario is less than ideal, the filter issue will be resolved very soon.

    I dialled back the map to moderate boost and things have improved a little, but most of the issues are at start up, and those few minutes where the car is idling on cold start. Definite misfire.

    I have ordered some new NGK Iridiums, and will clean up the coil packs when I fit them, but will get Andy to check the injector spray pattern in the next week or so.

    I'm actually as concerned by the amount of timing adjustment under heavy load as I am about the misfire, but this can be cured in part by the spray bar. It's only a few months until March when the 3 years warranty is up, so I am happier to start making more visible mods (as I own significantly more of the car than is outstanding on the Audi finance).

    The wife really doesn't want me to get the M3 CSL, saying too many chimps own M3's these days. She prefers the Porker so depending on the outcome of this little episode determines what early next year may look like car wise.

    Don't forget that Revo adjusted my map to compensate for the lack of DP/TBE so it's a variation on Revo 2+. If I am not going to keep the car long a full DP/system is out of the question as I can't recuperate the value over the short period.
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  17. Iggu
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    Iggu Active Member

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    -4 is nothing to worry about and if you run the car for a few weeks you'll see these drop to -2 as things adjust. When I first got my Stage 2+ I was seeing up to -6 on some cylinders but now I don't see anything more than -3. Someone we both know well has been running on GIAC with some other mods and has CFs of up to -11 throughout the rev range - with no problems. I would drive it at -4 quite happily as it will adjust in time.

    She has a very valid point there.

    I had forgotten that to be fair.
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  18. Kris
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    Kris Member

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    I've just sold my S3 although after nearly 2 years I never got bored of it nor had any problems, ran it with GIAC map and cat back. Was sad to see it goe but the call for change beckoned. I bought a 911 Carrera which is great to drive although i'm learning how to drive again after having had quattro. What it has made me realise that I took for granted was how forgiving with all the quattro electronic gismo's the S3 was when pushed hard and a bit more!

    I told Audi that if they had an RS3 then they'd have had a sale :icon_thumright:

    Hope you get yours sorted for some trouble free smiles per miles.

    Kris
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  19. warren_S5
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    warren_S5 Moderator Staff Member Moderator

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    ***UPDATE***

    Been out to have a look at this over my lunch break, and have found the following from a quick dig under the bonnet:

    Took the engine cover off, then undid the coil pack connectors:

    [​IMG]

    After closer inspection of the coil packs, there were some (oily?) residues on them which I did my best to clean off with electrical contact cleaning spray. I then proceeded to clean the inner shroud of the coil pack, then the contact points which connect to the loom.

    [​IMG]

    This same residue was seated around the entry point for the coilpacks, so I did my best to clean this off too:

    [​IMG]

    Proceeded to remove the remaining coil packs and clean:

    [​IMG]

    All coil packs out:

    [​IMG]

    Then started to remove spark plugs. Plug no.1 (washer bottle side) was not only loose, but I was able to undo it with my fingers :ohmy:

    I took the plug out, and considering how loose it was, it didn't look that much the worse:

    [​IMG]

    For those who have not seen a direct comparison with an OEM Bosch, the NGK is on the left in the following picture, the Bosch on the right. The NGK Iridium has a much smaller tip and contact electrode than the OEM Bosch, and this in combination with the hardness/electrical connectivity is why the Iridiums last longer / put less strain on your coil packs.

    [​IMG]

    All back in now (ran out of time in lunch break, so engine cover not yet back on - will do it tonight).

    [​IMG]

    One last look at the Carbonia as it will be gone VERY soon!!! Glad I checked it as one of the retainer screws had fallen out (again) so was held in by one metal cable tie!!! Screw was just sat in the hole, but unfastened so that was a bit of luck. Coming to a fleabay near you soon!!

    Have yet to fire her up, but hope the replacement of plugs / cleaning / tightening may now have resolved the issues.
    Last edited: Aug 25, 2009
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