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Thread: MAF Tuning question???

  1. #1
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    Unhappy MAF Tuning question???

    屏幕截图 2023-03-14 222041.png
    In hpt,under MAF Calibration;

    屏幕截图 2023-03-14 222248.png
    messured Mass Airflow in hpl;

    屏幕截图 2023-03-14 223019.png
    messured LTFT in hpl;

    Why MAF Calibration multiply messured LTFT not same with messured Mass Airflow?

  2. #2
    Senior Tuner
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    What are you trying to tune?

    For the LNF ecotec you use STFT.

  3. #3
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    I'm tuning 2017 ATSL (LTG Turbcharge)

  4. #4
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    I'm not sure I'm following your question.

    What are you using to measure Mass Air Flow? Why doesn't measured MAF not match your input MAF since you are telling it how much airflow is there based upon the Frequency it's reading?

  5. #5
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    屏幕截图 2023-03-15 222638.png
    I use channel:Mass Airflow(SAE) as measure Mass Air Flow.

    By this channel,I measured the Mass Airflow number as below,
    屏幕截图 2023-03-15 222133.png

    But In my hpt file,
    屏幕截图 2023-03-15 222522.png
    the input MAF different with Measured MAF,this confused me. In my understanding, they should be similar.
    Attached Images Attached Images

  6. #6
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    I don't know anything about your ECM but a couple of possibilities.

    I'm not sure what your filter is doing. Maybe it's filtering out a lot of your data and throwing the average off?

    Sometimes the sensor/SAE channel isn't the one to use. Maybe see if you have any other options and not use the generic sensor.

    I don't know of any other way to "measure" the airflow other than MAF frequency. Maybe that "airflow" is calculated from the VE and that needs a lot of work. Is this a mostly stock vehicle?

  7. #7
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    when i get rid of fliter,no effect on my result.

    Maybe that "airflow" is calculated from the VE and that needs a lot of work. ----- (It seems reasonable)

    my car is cadillac atsl

  8. #8
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    how are u adjusting the MAF ? u cant use mass airflow g/s against the hz of the maf to correct it, if im seeing what ur trying to do right ? u need to use a wideband to do the OL areas or u can use the trims for the CL areas to get the fueling closer to commanded which gets airflow closer

  9. #9