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Thread: Questions about the KR pid in scanner v2.24

  1. #1
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    Questions about the KR pid in scanner v2.24

    I see the pid can go negative or positive, when it goes positive, the value is excessively high, 127°?, but timing seems to decrease, and when it goes negative, say -1 or-2°, timing seems to increase, so, if its negative KR, the PCM is adding timing, and when its positive, it means its removing?

    Also, can I use the KR pid to at least know if the engine is knocking based on whenever I see that positive kr value?

    And Whats the meaning of the negative KR?

    How do I take timing out, assuming i need to take timing out? same borderline op table? Or do I remove from both, MBT and borderline op?

    I'm adding to the borderline op so far, but I haven't added a lot, barely 2° to 2500-4000rpm, .90 load and up, and 0.5° from 4000-7500rpm, same load, since I'm using 91 octane, and I don't know what kr looks like yet in the logs.

    Thanks a lot.
    Last edited by bluegoat06; 03-10-2015 at 11:15 AM.

  2. #2
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    Actually positive or negative kr doesn't seem to add/remove like I thought, I have for example 22° timing by 4000rpm, and kr pid displays -0.6°kr, and by 4500, timing goes down to 18°, while kr pid shows -1.9°, can I even trust the pid to say positive number means KR, or is it perhaps negative number means KR??

  3. #3
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    As a test, I took 2* out of lamda spark table in the 5000rpm cell, I don't know if it made any difference as the KR pid is still showing negative, however by 4500rpm, now I have 19.5* instead of 18*, wtf ?
    I wish we had like a timing 101 for this cars, it's so different from what I know from GM, it's frustrating to say the least

    What's is the MBT table in relation to borderline?, is this the same as the Hi octane vs Lo octane table in GM ?? and when I make changes to borderline OP, why i'm not supposed to make the same changes, in the same spots, for the mapped points borderline tables ?

    lambda spark base mbt, wtf ? why is making changes to the MBT table ?

    Any tips or links to engine timing for the Coyote engine would be highly appreciated, I feel like I did back in 2006 when I started tunig GM, didn't know crap, now what I know, it's kind of useless in this platform as I don't understand the relation between the 5000 tables for spark we seem to have... Damn.

    Here is the tune and a log in 3rd gear WOT
    Attached Files Attached Files
    Last edited by bluegoat06; 03-10-2015 at 01:11 PM.

  4. #4
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    MBT table is considered as the MINIMUM amount of advance to make the maximum amount of torque. The ecm uses calculations to come up with the minimum amount of spark commanded based on various tables such as tip-in, borderline, mbt, lambda spark, etc and compares that to the amount of torque requested to figure out how much timing to put in..Lots of variables to get it dialed in although tables like tip in can be populated so they are no longer in the equation.

    Also, the knock PID in the v2.24 scanner is pretty much non-functional..as it doesn't show true values, so no real correlation to be made using it. I am hoping 2.25 gets released SOON!
    Current toy- 97 SCSB OBS chevy forged 6.0/4l80 combo with a bit of boost..currently back under the knife

    To many previous vehicles to list

  5. #5
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    Thanks one more time Toyoguru.