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Thread: DFCO Question

  1. #11
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    I don't have my laptop here with me in afghanaland, but there is a table in COS3 that you can use to change the AFR for load/rpm. I set up the freeway cruising areas and high vacuum areas leaner than the rest of the table.
    E85 is NOT flex fuel.

    2003 Chevy S10 4.3L LU3 LS1B Auto
    48 LB injectors
    Race Proven Motors 2114 intake
    T70 turbo.

  2. #12
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    Ahh ok, yea I dont have the experience yet for the COS's

    For the record.....if in DFCO (I was in 4th gear and allowed it to engage coasting downhill) and I cruised to slowing down, it turned itself off at 25mph. I need to check my settings on that. I am guessing thats the 'MPH to allow dfco to occur' setting. I wanna see if 25 is exact my setting or if hysteris has to do with it. I dont really understand hysteris settings.

    BTW, most conservative driving with some spirited heavy right foot a few times a week.....I am getting a solid 16mpg on the trucks trip/data display. Got it up to 16.5mpg a week ago super conservative driving. Again, I work 10 miles from home, and colder mornings with my 180* stat, my eng operating temps get there just shy of my work. So relatively on a daily basis (Mon-Sat my work days) I have short trips. Id prob avg better mpg if I had longer trips per drive.

  3. #13
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    Quote Originally Posted by Mikz86ta View Post
    I dont really understand hysteris settings.
    I wish someone could explain the hysteresis settings, they are confusing me as well, so I left them stock.
    2001 Silverado 5.3L ECSB 2WD T56:
    T76 turbo, Meth injection, 72# injectors, 799 heads, 212/212 114LSA cam, Built 4L80E, 3.42's
    EFILive V1 Commercial, COS5 2-bar SOLSD, AEM wideband

  4. #14
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    Thaks for your continued service KIF. Hope you make it back safe and soon from the big sandbox !

    Its kinda like 'history but thats about all I understand really

  5. #15
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    I remember now why I changed 3314 to 25mph......cause when I would be cruising thru the neighborhood (esp in the cold mornings) or thru a parking lot, DFCO at lower speed enable as it used to be would kick on. Causes alot of exhaust pop-pop-pop with my very free flowing exhaust. Was annoying. Figured 25mph was typically the highest speed I would ever go in those situations.

    I dont know the difference in 3309 and 3318 since they both say RPM Enable
    As well as 3310 and 3320 which are both MAP Enable settings. Tho 3320 has both enable and disable graph and settings.

  6. #16
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    Quote Originally Posted by ferocity02 View Post
    I wish someone could explain the hysteresis settings, they are confusing me as well, so I left them stock.
    I will have to think about this more in terms of DFCO....but, for the time being, here is a definition in terms of tuning in general that explains it. RPM and Rev Limiter is easier to understand since most of us have hit the limiter before in RPM



    its basically the time/units needed to activate or deactivate something...the actual definition of it is

    The lagging of an effect behind its cause,

    but i doubt thats what your looking for, but as an example lets say your talking about the rev limiter. Lets say the hysteresis is 300 rpms well If the rev limiter is set to 6300, once you hit that even with your foot to the floor the engine will not attempt to rev again until 6000 rpms. 6300-300(lag time)=6000 hope that explains it for you.

  7. #17
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    Ok, that's kinda what I thought too. It's like a buffer.

    The description in EFILive is...

    DFCO RPM Hysteresis: Engine speed must remain above {B3318} "DFCO RPM"(Enable)-this value to enable DFCO.
    DFCO MAP Hysteresis: Manifold pressure must remain below {B3320} "DFCO MAP"-this value to enable DFCO.

    I understand your example, but for DFCO you can specify the enable and disable MAP and RPM, so it appears the hysteresis's are not needed??
    2001 Silverado 5.3L ECSB 2WD T56:
    T76 turbo, Meth injection, 72# injectors, 799 heads, 212/212 114LSA cam, Built 4L80E, 3.42's
    EFILive V1 Commercial, COS5 2-bar SOLSD, AEM wideband

  8. #18
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    The description gives me a headache...
    Engine RPM must be above the "Enable" value to enable DFCO.
    If DFCO is active and engine RPM falls below the "Activate/Deactivate" value, then DFCO is deactivated.

    When all of the DFCO enablers are met, hitting any DFCO activate level will turn on DFCO. After DFCO has been enabled hitting any DFCO disabler or hitting every DFCO deactivate will turn off DFCO.
    If you look at Enable/Disable and Activate/Deactivate which is very confusing! Change the way you look at them to Enable and Disable it works well.

  9. #19
    Lifetime Member EagleMark's Avatar
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    What are some of the DFCO Paremeters referring to? M6? Manual Trans? Looks like all mine are off...

    Although my {B3314} is all set to 15KMH I never get any DFCO till after 40 MPH and if in DFCO it disables at 40 MPH? Maybe I have a VSS setting off? Although all stock and auto trans maybe something in M6 is preventing any DFCO below 40 MPH?

  10. #20
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    I'm running basically stock 01 Silverado 5.3L 12208322 settings with some adjustments to the RPM and MAP curves. You can find the stock tune on tunefiledepot.

    I agree the description is a bit confusing, but here is my take... Enable means DFCO is "armed" but not running, as in not cutting fuel or reducing spark. Activate means it's armed and cutting fuel and spark.

    In order for DFCO to arm, you must satisfy ALL the enablers for ECT, VSS, RPM, TP, and MAP. Then for DFCO to activate you must satisfy EITHER the RPM or MAP activate/deactivate level.

    According to the description you have to satisfy both the RPM and MAP deactivate in order to deactivate DFCO. However, I have found that you only have to hit one or the other to deactivate DFCO. In my setup I usually hit MAP deactivate first.
    2001 Silverado 5.3L ECSB 2WD T56:
    T76 turbo, Meth injection, 72# injectors, 799 heads, 212/212 114LSA cam, Built 4L80E, 3.42's
    EFILive V1 Commercial, COS5 2-bar SOLSD, AEM wideband

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