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Thread: Frustration dialing in VVE - E38

  1. #1
    Tuner in Training
    Join Date
    Jan 2020
    Posts
    27

    Angry Frustration dialing in VVE - E38

    Hey guys, hoping someone can point me in the right direction.

    I have been working on a tune that was started by a reputable shop and then they never finished the tune after my header install.

    I have the MAF dialed in pretty good. I am using an AEM WB.

    I moved on to the VVE tuning next. I pulled 4* timing from my whole table and then got to work.

    The MAF is disabled as well as DFCO, etc.

    My first log with the maf disabled the VVE table was 14-20% lean. I multiplied the error percent and it slowly brought everything down.

    This is the point I have issues with. Once I have it pretty close within 6% error in most areas and down to .5% in others, I now multiply the error by half instead of the full percent The error then swings far in the other direction preventing me from really getting the entire table dialed in nicely.

    I did around 20 tunes / logs and dialing in yesterday and had to start over as the idle was surging the farther along I got.

    I started over today and a lot of the table is in a decent place, but the rest is pretty rich or lean in areas.

    IDLE IS GOOD.

    I am now on version 7 today and 27 overall. I feel like I am not getting any closer.

    My 3d chart is also all kinds of crazy.

    Any recommendations on how to finish this step of tuning and move on to the spark tables?

    I have attached the first tune that was super lean and now where I am along with the logs for both.

    Any help or pointers would be appreciated.

    Mods:
    1 7/8 headers and 3" x pipe.
    LS3 otherwise stock

    Thank you!

    Step 5 with Step 8 3200plus.hpt
    Step 5.hpl
    Step 1 VVE Setup and -4 timing.hpt
    Step 1.hpl

  2. #2
    Senior Tuner
    Join Date
    Mar 2011
    Location
    Ripley, MS
    Posts
    1,865
    On a stock engine with headers, the stock VVE table should be close. It should only require small adjustments. You have added over 15% to the VVE table in the idle area. There is no way this is correct.
    I would start with the stock VVE.

    There has to be a problem with your wideband or your math.

    Where is your wideband installed? Are there any exhaust leaks that could be affecting the accuracy?

  3. #3
    Tuner in Training
    Join Date
    Jan 2020
    Posts
    27
    Hi there.

    The WB is in the bung on my kooks headers right past the collector on the driver's side bank.

    Brand new WB.

    The tune labeled "step 1" is my first log with the with the MAF turned off. My log for step 1 shows around 14% off almost across the board.

    When I tuned the MAF and has that dialed in, the car felt great. I have the MAF dialed in within a percent or so. Not sure the WB is bad.

    Appreciate your input. Curious what could be so off with this tune. It's driving me nuts.