1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Haldex problems on Dyno

Discussion in 'A3/S3/Sportback (8P Chassis)' started by Shane., Oct 21, 2010.

  1. Shane.
    Offline

    Shane. Member

    Joined:
    Feb 8, 2010
    Messages:
    504
    Likes Received:
    2
    Had the car mapped a while back and since then me and the guy who did it been tweaking and fixing few bits. Using a 2wd dyno with the haldex fuse out we can't seem to get over a certain point, it's as though it pulls all the way to a certain point and then drops off the abs doesn't seem to like fuse being out and we think this could be the problem (possibly acting as a limiter on the haldex ecu)

    Spoke to a place with 4wd rollers today and they said they have had similar problems with them as the haldex system doesn't tend to react well to separate drive rollers either.

    Just wondering if anyone else has ever had these issues? Car is flat spotting at 255bhp no matter what we do but according to the readout were getting on the diagnostics (and a few golf gti 2.0tfsi running the same software) the car should be be pushing 282bhp

    Thanks
    Shane
    #1
  2. PH1L
    Offline

    PH1L Gievf Buckets

    Joined:
    Jan 8, 2010
    Messages:
    3,864
    Likes Received:
    39
    have you considered disconnecting the prop shaft?
    #2
  3. paddy
    Offline

    paddy Audi=No fault code, no idea

    Joined:
    Feb 6, 2008
    Messages:
    5,133
    Likes Received:
    122
    A couple of points. by running on two rollers you are not going to get a true reading because your ignoring part of the drive train that saps power ie the prop and diff.
    It sounds to me like you are reaching the limit of something like the flow of the the Cat/Exhaust/intake/filter....what rpm is it topping out at because thats more relevant than the bhp. We had a simular problem with mine on a 4WD roller, it topped out at 255 bhp no matter what we did and came to the conclusion it was as much as the cat would flow. We could move that 255bhp point up and down the graph a bit and increase the Torque but it just would not flow more than 255. One other poiint, we found we could gain 10bhp with Tesco 99ron over 95ron, petrol quality becomes important when you are looking for the last 20 bhp. ( as does tire pressures etc)
    Did you check you were getting full bhp beforeyou added any changes ? Cars will easily vary 10% bhp from stock after a year or two anyway so were you starting from 190bhp instead of 210 for example.
    Last edited: Oct 22, 2010
    #3
  4. Shane.
    Offline

    Shane. Member

    Joined:
    Feb 8, 2010
    Messages:
    504
    Likes Received:
    2
    Exhaust and intake are standard really just changed to a k&n panel filter and took the restricter cone out of the airbox. Not sure on the RPM but what we could see from the dyno is that the torque seems to pull and pull then hit some flat spot and drops off even though the car feels like it wants to keep going.

    The only reason we went against components being the problem as the mk5 gti running all standard had a highest reading at 282bhp so the only thing different is haldex system. Someone on another forum mentioned they had heard of a limp mode when the ABS isn't working properly, as some sort of Safety feature I'd imagine? When driving the car it doesn't seem to drop off aswell it keeps on pulling right through the rev range

    Thanks
    Shane
    Last edited: Oct 22, 2010
    #4
  5. Boydie
    Offline

    Boydie Boycie

    Joined:
    Dec 24, 2006
    Messages:
    2,834
    Likes Received:
    193
    Take it to a 4wd dyno - that is where you will get best results. Even there you will still experience a few issues.
    #5
  6. S3Alex
    Offline

    S3Alex Rarely neutral

    Joined:
    Dec 3, 2008
    Messages:
    5,643
    Likes Received:
    1,219
    Definitely need a 4WD R/r to run it on.

    Major problems seem to be ambient temperatures and how well the car is secured in getting repeatable results.
    #6
  7. Shane.
    Offline

    Shane. Member

    Joined:
    Feb 8, 2010
    Messages:
    504
    Likes Received:
    2
    I will wait til I can get it on a proper 4wd dyno then. Was gunna go to Power station tomorrow but by sounds of it I need a 4wd dyno instead of theres which apparently works as 2 2wd sets of rollers so could still cause problems with Haldex (theirs is set up for jap cars which are mechanical AWD)

    Thanks
    Shane

    Edit: A guy over on another forum had a chat to his mate who's a VAG technician, he said he has seen it before where haldex system being disengaged sends the ABS mad which then limits the outputs of the car (a sort of Limp mode)
    Last edited: Oct 22, 2010
    #7
  8. LWNY
    Offline

    LWNY Member

    Joined:
    Nov 3, 2009
    Messages:
    161
    Likes Received:
    2
    Can't you just pull the handbrake up which disengages the Haldex?
    #8
  9. akash_sky1
    Offline

    akash_sky1 Active Member

    Joined:
    Nov 14, 2009
    Messages:
    1,191
    Likes Received:
    5
    Hi, there is NO WAY a K03 car with standard intake and exhaust and just remap will make 282 bhp at the fly ( I assume you meant at the fly).

    An increase of 80+ BHP in the K03 2.0T is only just possible with a stage 2 tune like mine plus the Autotech pump which Im about to get. Want a slight increase over that and you need a new FMIC and improved hardpiping for the turbo/IC.
    With standard airbox and cat/downpipe and stage 1 map there is no way you would get that power. I think the flywheel figure you are getting now is more then likely the max of what your car is capable of putting out.

    Calculating/quoting power at the fly is pointless anyway as there is always an error in using the drag to calcuate the power at the fly, WHP is much more relevant as that what's actually getting to the road, and that's what always measured most accurately.

    Also if your saying that same dyno measured a standard mk5 GTI as 282 bhp that is completely absurd and shows how optimistic that dyno was! And also how much error there is on some dynos in calculating power at the fly.
    Last edited: Oct 22, 2010
    #9
  10. paddy
    Offline

    paddy Audi=No fault code, no idea

    Joined:
    Feb 6, 2008
    Messages:
    5,133
    Likes Received:
    122
    I have to agree with Akash except i guess you are talking at the wheels if you are on a 2WD roller setup which means you must be on stage 2+ at least, bigger Turbo int cooler and so on..in which case i still say you will not flow that with a std airbox and exhaust. As for limp mode !! If your car drops to 250bhp in limp mode then its not on the same planet as the rest of us......lol
    As i said, get it on a 4WD roller but even then take the results with a pinch od salt and if its DSG, with a mug of salt. The only real value of a dyno is before and after comparisons on the same car on the same dyno.
    #10
  11. akash_sky1
    Offline

    akash_sky1 Active Member

    Joined:
    Nov 14, 2009
    Messages:
    1,191
    Likes Received:
    5
    Realistically, with just a stage 1 map your car will be making about 240 bhp MAX. Dynoeing on a stage 1 is not really that useful anyway, as there is no tailoring to be to done to the map and no other parts to adjust around, such a new downpipe etc.

    Also on an optimistic dyno such as the one you are using, this figure will be pretty inaccurate anyway. In the UK most tuners/dynos seem intent on quoting flywheel power, one thing they have right in the US is that they only regard WHP as a credible reference.
    #11
  12. leach76
    Offline

    leach76 Member

    Joined:
    Feb 26, 2009
    Messages:
    305
    Likes Received:
    3
    Mine dyno'd at 245bhp with giac standard pump map and an evoms but no exhuast but as said above to get anywhere near 280bhp your going have to go a bit further with the mods,giac do the baby hammer map for the ko3 now which requires hpfp and exhaust decat system but still dont think it would see 282 the claimed golfs are getting,and a lot of claimed fiqures are just claimed and a lot of the time from what i have seen often well off as many of decent tuning companies struggle getting there figures with quattros on dyno's. Lastly whats the car feel like? is it running safe? and has it got nice power and torque curves ? if it has who cares because its not how much power it has its,its how it feels and how it makes its power
    #12
  13. akash_sky1
    Offline

    akash_sky1 Active Member

    Joined:
    Nov 14, 2009
    Messages:
    1,191
    Likes Received:
    5
    Yes that's right. Im getting that K03 Hammer done soon when new Sachs clutch is finally sorted out ( leaking Concentric cylinder I think) .
    Then I'll see how long that will keep me entertained...already lookin at new vehicles for next year.
    #13
  14. dave_ph
    Offline

    dave_ph Member

    Joined:
    Jan 23, 2010
    Messages:
    47
    Likes Received:
    0
    me and badger bill tried this and it didnt work
    #14

Share This Page