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Thread: Help with VE and LTFT tuning

  1. #1
    Potential Tuner
    Join Date
    Jan 2024
    Posts
    1

    Help with VE and LTFT tuning

    New to tuning. Started about 2 weeks ago tuning challenger. Only mods done are 3.17 litens pulley swap, corsa CAI and corsa exhaust. I dont have any goals yet for the car besides squeezing out as much power I can from tuning and the mods i currently have. After a bunch of trial and error i started from a clean slate again and redo the tune. my steps are

    1. tune ve tables
    2. adjust fuel trim levels through inj pw x fuel mass
    3. spark timings.

    was hoping if someone can assist/guide me if im on the right path. all datalogs are street. I dont have access to a dyno but i can get more datalogs if needed

    i adjusted my ve tables and went on a drive to datalog the new ve table (labeled before). note that i reset all adaptive through vcm scanner before this datalog drive.
    the tune and datalog
    before.hpl before.hpt

    went through the log and did a few tweaks to the ve table. the adjustments i did from what ive learned so far was data from the LTFT table. saw which cells were running lean (positive red number cells) and decreased the value in the ve table. the cells that were running rich (negative green cells) i added the value in the table. then did some more datalogging. these 3 are on the same tune (labeled after)
    adjusted ve tune and logs
    after.hpt after.hpl after2.hpl after3.hpl

    Before i start making more adjustments i have a few questions... in the datalog (after.hpl before.hpl), the ltft tables are pretty identical with some lean cells. the next two datalogs (after2.hpl after3.hpl) are identicle to each other being more rich in every cell. could this be from the reset adaptive i did and the ecu is learning at the moment? if not, what else could cause it to be all rich? this is where it has me second guessing myself if i am doing anything correctly. My next guess would be to increase the values in the ve tables so the cylinders can get more air to mix with the extra fuel... but if i do that then how would i know if my engine is at its max VE value? I have cells that are hitting %120 VE already and unsure if thats already to high. If i leave it as is and start adjusting the inj pw x fuel mass to get it down closer to %0 ltft theres a possibility im leaving performance off the table correct?

    Desktop Screenshot 2024.01.25 - 15.45.49.04.png i also did pull some KR on the very last run also. what i think is different is that i turned off chiller mode but i cant remember.
    Last edited by jmn10311; 01-25-2024 at 04:02 PM.

  2. #2
    Tuner in Training
    Join Date
    Jun 2021
    Posts
    19
    start wit a new file again turn of neural network off, do not change the injector data, reset adaptive fuel trims setup your short trim fuel tables in vcm scanner log and copy that data and multiply by half to your ve tables, for this to work correctly you have to have a most of the cels populated if not interpolate manually in excel, reset fuel trims again load new tune in and repeat, your power enrichment tables is way of too for boost

    negetive values means to much fuel so you have to take some away positive red values you have to ad fuel