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Thread: LS2 402 lean idle

  1. #1
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    Default LS2 402 lean idle

    How much overlap is too much to tune using factory sensors in closed loop? Idle AFR is ~ 18:1 on wideband. MAP reads ~65kpa at idle. Cam has about ~20* of overlap.

    AFR225 heads, LSX intake, 90mm TB, 1 7/8 headers w/ 3" duals and an H-pipe.

    Here is a link to a log setup for autove. www.fast-ta.com/tune/402/misc/autove.efi
    Last edited by white2000ta; April 2nd, 2006 at 04:04 AM.

  2. #2
    Lifetime Member TAQuickness's Avatar
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    The PCM isn't concerned a much with overlap as it is with injectors. Overlap effects can be overcome with a vacuum pump and/or higher idle speeds.

    From your log, I only see a maximum of 16.5:1 near the idle areas. Did you apply filters to your logged data?


  3. #3
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    Quote Originally Posted by TAQuickness
    The PCM isn't concerned a much with overlap as it is with injectors. Overlap effects can be overcome with a vacuum pump and/or higher idle speeds.

    From your log, I only see a maximum of 16.5:1 near the idle areas. Did you apply filters to your logged data?
    I applied the standard autotune filters on that logfile. I have 42lb delphi (racetronix) injectors. Here is a long run of the first outing at the track. This is not in SD. http://www.fast-ta.com/tune/402/race.efi (inlcudes idle in stage lanes, burnout, and run) It doesnt look like it hits 18:1 exactly, but the LTFT are pegged and its in the high 17s.

  4. #4
    Lifetime Member TAQuickness's Avatar
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    White - replied to your pm


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