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Thread: Open loop table

  1. #1
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    Open loop table

    The open loop table in an 0411 pcm. Is this just a desired value the pcm looks at and adjusts from your VE table? How is this table "tuned"? Is that the point of open loop STFT?
    Thanks guys
    1997 30th SS. Torqhead 24x, TFS heads, 223/235 cam, 4l80e, S60 D1SC 14psi

  2. #2
    Tuning Addict 5FDP's Avatar
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    The open loop Eq ratio?

    If you are talking that table, it's only job is to tell the computer what to command. So if it says 1.00, that is stoich and you are calibrating the VE or MAF table to achieve that. If you have STFT active in open loop, it will use the trims to try and reach maintain stoich.

    The table is normally richer at colder coolant temps as it's easier to run an engine with more fuel when cold and emissions reasons as well. Then it ramps it's way towards 1.00 as it warms up.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  3. #3
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    Quote Originally Posted by 5FDP View Post
    The open loop Eq ratio?

    If you are talking that table, it's only job is to tell the computer what to command. So if it says 1.00, that is stoich and you are calibrating the VE or MAF table to achieve that. If you have STFT active in open loop, it will use the trims to try and reach maintain stoich.

    The table is normally richer at colder coolant temps as it's easier to run an engine with more fuel when cold and emissions reasons as well. Then it ramps it's way towards 1.00 as it warms up.
    Yup you got it.
    I knew the answer just wanted clarification lol
    1997 30th SS. Torqhead 24x, TFS heads, 223/235 cam, 4l80e, S60 D1SC 14psi