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Thread: Please help me understand the autotune etc.

  1. #1
    Junior Member
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    Default Please help me understand the autotune etc.

    I deleted the incoherent babbling I previously posted and narrowed it down to this:

    Why would I get a BEN value of less than 1 if the cell is alread too lean?
    more specifically:
    In cell, 1200 rpm X 100kPa, my WB02 read an AVG of 15.48:1 (127 counts eek)
    The BEN factor for that same cell is .93
    Does that make any sense to anyone?
    Shouldn't it be greater than 1?
    Last edited by kenkaru; October 7th, 2006 at 11:38 AM.
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  2. #2
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    Commanded AFR changes as certain conditions exist. Heavier throttle enables PE (power enrichment) mode which richens your mixture up to that commanded in B3618.

    The reason you want to multiply VE table by the BEN factor is to bring your Actual AFR into commanded.

    Example.
    Commanded = 12:1
    Actual = 11.7:1

    To bring your actual up to what is commanded, you need to lean your VE table out by 2.5%. Multiplying that point on your VE by the BEN value (0.975) will bring that in line.

  3. #3
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    If B3618 is all 1.00's, what AF is it shooting for? 14.63?
    Thanks!

  4. #4
    Lifetime Member TAQuickness's Avatar
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    depends on what unit's you are viewing it in. What value is stored in B3601. For EQ Ratio and Lamda, a value of 1 = B3601. For AFR, a value of 1 = 1:1

    Just incase you are not familiar with the difference between EQ Ratio and Lamda...

    EQ:
    Final AFR = B3601 / EQ

    Lamda:
    Final AFR = B3601 * Lamda


  5. #5
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    Thanks! I'm viewing 3618 in Lambda and it's all 1.0's down a single column on RPM.

    I had no clue about EQ and Lambda so thanks for that

    So the car will always go for 14.63 unless it's in PE mode, in which case it will run (14.63*lambda) ?

    Thanks a lot I'm really getting a lot out of this already.

  6. #6
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    Assuming what I said above is true, how can I get it to run a different A/F outside of PE mode? ie if I wanted to add fuel to the 1500 rpm x 50 MAP cell to kill some bucking. or are there better ways to combat bucking?
    EDIT: I think I found it in B3605 right?
    Last edited by kenkaru; October 8th, 2006 at 01:57 AM.

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