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Thread: WOT, throttle is closing

  1. #1
    Tuner in Training
    Join Date
    Aug 2020
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    30

    WOT, throttle is closing

    My TB is closing on me hitting some limit I assume it's my virtual torque table, but I am a newbie to all of this. Here are my logs.

    Few other issues, adding numbers to the VE table, I did the whole copy and paste multiply by half and my fueling got worse. When you add numbers into the VE table you're adding fuel correct?

    Aem wideband 30-0334, I can get it to read with WB EQ Ratio 1 (SAE) and not using the specific aem pids.

    Throttle body seems to be way higher than the accelerator.

    Car is on E85

    2013 Cruze
    Attached Files Attached Files

  2. #2
    Tuner
    Join Date
    Feb 2019
    Location
    Lodi, CA
    Posts
    174
    Ok. So, first, set your Virtual Torque tables back to stock and leave them there for now. That is why your TB is opening up so much. Now, with electronic throttle bodies, don't expect the pedal position and throttle position to match. Just don't worry about it for now.

    The first thing I recommend is tuning your VVE tables via your short term fuel trims. in speed density/closed loop. I did a writeup here:

    https://www.cruzetalk.com/threads/ho.../#post-3254533

    I need to update it to say to leave your PE settings where they are. You also need to disable clutch fuel cutoff, deceleration fuel cutoff, hot engine and hot turbo protection, cat overtemp protection, etc. Anything that is going to add to your fueling will screw you. So, when in speed density, the ECM will only be referring to predicted airflow, not calculated. Disabling the MAF (calculated) will force it to reference the VE coefficients. Turning off the stuff listed above will help to not skew your data. You will also want to set filters in your scanner to filter out commanded torque 1% and lower and accelerator pedal position to 1% and lower. This will stop your numbers from getting skewed when letting off the pedal and not moving.

    Then warm up your car to operating temp, and got for a drive, and light up as many cells as you can. Long, slow, easy all the way through the pedal (I like to get on the freeway and sllloooowwwlly creep into the pedal to the floor and slowly creep back. You should be plotting your short term fuel trims which is basically the error percentage/ratio between your commanded lambda/eq/aft and what your computer is seeing and attempting to correct for and averages out to. Make the scanner's graph match your VVE table exactly, and then when you take the log, copy all of the data, and highlight the whole vve table and right click -> paste special -> multiply by % (if your vve logs show more than -+ 10% error) or multiply by %/half (if you are closer to zero. it stops you from chasing your tail by overshooting your target). Then find cells that have NOT been populated and smooth between adjacent ones that have been changed. I like to interpolate as long as they are 1-3 cells max between two cells that have been updated. This will get you closer faster. Then after I take care of those, I usually got around the outside and interpolate between the edge of my changed cells, and 1-2 cells around the outside so that it helps to blend them in with the unchanged ones around where you managed to get data. Some people like to hand smooth, but I have found it to be very arbitrary how you do it. Just got lots of good data, and do as listed in that link and how the OGs do it. You really don't want to change cells that you just updated, as they would just skew the data form the logs.

    Once you have done that, click the calculate button on the left, then copy your whole vve table after it calculates everthing , and copy that to the other 3 VVE tables (open, closed, etc). After a few times, you will come closer and closer to zero. When you get them -+1-3% of 0 in your logs, you can put a pin in that and it should be good to go.

    The reason you are getting it wrong with your wideband, without looking, is you probably have fueling adders throwing fuel it, and I have simply found a wideband NOT to be effective for VVE tuning outside of using it for WOT (STFT is disabled in open-loop).

    Give me a few and I will change your tune you have here to be set up for SD/closed look and ready to use for VVE tuning, if you haven't already figured it out. Then you just need to set up your channels and a graph in scanner according to the link I have given above (or how you have read elsewhere. Just make sure your scanner matches the VVE table in editor. ). Now the main reason after looking at it again, is because you are using WB EQ ratio; you nee to get the error percentage. The forumla is something like:

    100 * ((wb lambda - commanded eq) / commanded eq)

    If I remember correctly. Then you will start seeing numbers show negative meaning you are rich and it needs to take away X amount of fuel, or positive, which means it will want to add X amount of fuel.

    Your VVE tables are not just adding fuel. They control timing and stuff too. VE, or volumetric efficiency is, in this table's case, and therefore the coefficient's case) a model of the airflow of your engine based on RPM vs your pressure ratio (MAP / baro). So you are not adding fuel. You are telling the ECM how much air you are getting, so that it can add fuel properly. It's incredibly important to have this table as good as you can get it, and ALWAYS update it if you change airflow (adjust cams, new cams, up boost, open exhaust, etc). Literally anything that changes air flow, this table needs to be adjusted. If this is off, it will also throw off your PE. It's essentially the base for all of the fueling in the vehicle. As far I understand it, anyway.

    brb with the modified tune file.

  3. #3
    Tuner
    Join Date
    Feb 2019
    Location
    Lodi, CA
    Posts
    174
    Actually I cannot read your file because it's part of a remote tuning session or something. Anyway, hope that sheds some light. If you are interested, I can help you tune it. My fee is quite modest if you are interested.