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Thread: Dynamic Cyl Air and Calculated Cyl Air

  1. #1
    Tuner
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    Dynamic Cyl Air and Calculated Cyl Air

    What is the difference between the two? It seems the timing chart pulls from the dynamic cyl air but there is a user defined PID that comes with HP Tuners. Just wondering what the differences between the two are.
    Jason
    01 Camaro Z28 LS3 525hp Built 4l60e
    74 Camaro Z28 LT 355 fully forged roller with t56 4.56 gears

  2. #2
    calculated cylair is calculated from the MAF airflow and RPM. cylinder airmass is directly logged from the PCM.
    I count sheep in hex...

  3. #3
    Tuner
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    So these two should be in line with each other if your airflow is setup correctly? I would expect discrepancies between them in rapid change states of the engine though.

    They shouldn't be like drastic differences though in steady states (i.e. calculated cylair .67/cylinder airmass .85) right?
    Jason
    01 Camaro Z28 LS3 525hp Built 4l60e
    74 Camaro Z28 LT 355 fully forged roller with t56 4.56 gears

  4. #4
    Tuner
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    bump?
    Jason
    01 Camaro Z28 LS3 525hp Built 4l60e
    74 Camaro Z28 LT 355 fully forged roller with t56 4.56 gears

  5. #5
    in theory yes at steady state they should be close.
    I count sheep in hex...

  6. #6
    Senior Tuner
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    since the calculated one is MAF based, if your SD-related tables are miscalibrated, and every time your hybrid mode will be using the SD portion, or just run in pure SD, the calc one will be off. Also, if you've gone pure SD, modded things, and have not touched MAF since then, the calc one will be off as well.

    simple version: use the dynamic one, unless you really know what you're doing.

  7. #7
    Senior Tuner DSteck's Avatar
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    I always use dynamic because that's what the PCM is actually using as spark lookup.

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