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6AT Post shift timing corrections - lets end this.

Discussion in 'Advanced Tuning | Coding' started by all4bspinnin, Aug 30, 2017.

  1. Jboyorak

    Jboyorak Private

    Messages:
    45
    Location:
    Maine
    I haven't been active for 2 years(or done anything with my car), so my memory is fuzzy right now. I am just getting back into a place where I can play with my car once more.

    IIRC, I ended up fixing my issues by never reaching target boost/load. I ended up tuning everything to the point where I was always just under targets. This fixed both post shift throttle closures and post shift timing drops. How I did this...I can't remember as of right now. I know it isn't super helpful, but with any luck I will be diving back into the tuning aspect of things
     
  2. all4bspinnin

    all4bspinnin Corporal

    Messages:
    125
    Ride:
    135i TT
    Anything is helpful. I've tried this approach several times with no effect. You can lower base wgdc table/adder airflow while raising load target to do this (proving p fact doesnt make up the difference). The problem mostly surfaces on e85 due to the higher torque, timing, etc. Im working on the approach RSL recommended. I hope to have more info soon.
     
  3. mfractal

    mfractal Lurker

    Messages:
    16
    Ride:
    E90 Sedan LCI 335i FBO MHD E40
    i'm experiencing the same issue. FBO w/o inlets on stock turbos. I'm tuned with V8Bait, the map is super strong and i am very happy with all aspects of it, all but the corrections post shift. We've tried different E-mixtures and many map revisions but unfortunately the post shift corrections are still there.

    Hopefully MHD will introduce the timing re-introduction tables to all and that will help.

    here's a log of mine btw : https://datazap.me/u/mfractal/justin-e50-rev03?log=0&data=3-7-8-9-10-11-12-24
     
  4. Jeffman

    Jeffman Lieutenant

    Messages:
    793
    Yep. Your Cyl4 timing pull is pretty massive. Have you tried any/all of the suggestions made in this thread?
     
  5. mfractal

    mfractal Lurker

    Messages:
    16
    Ride:
    E90 Sedan LCI 335i FBO MHD E40
    To be honest i do not know what was done in the map to try and correct it as i wasn't tuning it myself. @V8bait (Justin) was.

    Cylinder 4 does seem to be the most affected one, i wonder what that means.

    BTW here's a log with more agressive timing : https://datazap.me/u/mfractal/justin-e50-rev02?log=0&data=3-7-8-9-10-11-12-24

    and here's one with much less timing requests, you can see it's totally clean : https://datazap.me/u/mfractal/justin-e50-rev01?log=0&data=3-7-8-9-10-11-12-24
     
    Last edited: Apr 10, 2018
  6. jyamona

    jyamona Lieutenant Vendor

    Messages:
    651
    Location:
    Philly
    Do the same corrections show up on a 2 gear dyno pull? If so, is someone able to get det cans on the motor and see if noise is increasing during the shift?
     
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  7. bradsm87

    bradsm87 Corporal

    Messages:
    156
    My Cyl 4 is usually the worst also. The least compromised option I can think of right now is probably to use aggressive timing reduction by charge air temp at around 5000rpm. That way at least you can get your full timing in a single gear run but pulling into a subsequent gear when IAT is higher, you can set it up to have less timing, making the drops less severe.

    Still very compromised though but less so than simply pulling timing out of the timing main map.
     
  8. jyamona

    jyamona Lieutenant Vendor

    Messages:
    651
    Location:
    Philly
    So let's assume it isn't just extra noise during a shift (if so, the problem could be handled differently). Over how many ms do you think timing would need to be re-introduced in order to avoid the corrections?
     
  9. bradsm87

    bradsm87 Corporal

    Messages:
    156
    I think 150ms would be a good starting point for testing and it's above logging sample rate so we will be able to see it in logs. From there, if timing drops get better, we could incrementally drop it back as much as possible without the bad timing drops.
     
  10. jyamona

    jyamona Lieutenant Vendor

    Messages:
    651
    Location:
    Philly
    150ms, linear ramp?
     
  11. bradsm87

    bradsm87 Corporal

    Messages:
    156
    Yeah that'd be a great starting point I think.
     
  12. all4bspinnin

    all4bspinnin Corporal

    Messages:
    125
    Ride:
    135i TT
    Yes. Should work. Only one way to find out

    Nice to see you in here asking questions. It means youre working on it.
     
  13. Cheezy

    Cheezy Lieutenant

    Messages:
    548
    Location:
    Toledo Ohio
    @jyamona did you have any luck testing your 150ms reintroduction theory?
     
  14. jyamona

    jyamona Lieutenant Vendor

    Messages:
    651
    Location:
    Philly
    So far it worked in an F-series test, but it was applied to every shift which made normal driving shifts slower and sloppy. It will definitely need some more work when time allows.
     
  15. mfractal

    mfractal Lurker

    Messages:
    16
    Ride:
    E90 Sedan LCI 335i FBO MHD E40
    There's an F series with 6AT in it ? Wasn't aware..
    So when you say it worked you mean post shift corrections were gone ?

    BTW, you've asked above if it happens from 2nd to 3rd - just saw this this week on a friend's car. it does.
     
  16. jyamona

    jyamona Lieutenant Vendor

    Messages:
    651
    Location:
    Philly
    Not 6AT, but the logic is in the DME so trans is irrelevant. And yes corrections were gone.
     
  17. Rob09msport

    Rob09msport Lieutenant

    Messages:
    671
    Location:
    Monroe CT
    Ride:
    09 335i msport le mans 18 x5
    Do you do pro tunes?
     
  18. Rob09msport

    Rob09msport Lieutenant

    Messages:
    671
    Location:
    Monroe CT
    Ride:
    09 335i msport le mans 18 x5
    I would want v8bait jyamona or you to tune my car
     
  19. doublespaces

    doublespaces Administrator

    Messages:
    6,424
    Location:
    AZ
    Ride:
    2009 E93 335i
    @jyamona doesn't do engine tunes, he more or less writes code in the ecu for the engine tuners to use.

    The F chassis has only had an 8HP in terms of automatics, as far as I know.
     
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