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Thread: Little Help Interpreting Logs - TQ Modeling - 2018 ZL1

  1. #1
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    Question Little Help Interpreting Logs - TQ Modeling - 2018 ZL1

    I could use a little help interpreting this log. I believe I'm logging the correct information, but I'm not seeing exactly what I expected. Specifically around these charts:

    predicted engine tq vs delivered eng tq vs max eng tq. I was expecting to see the predicted higher than the max now that I've got full timing in it with dialed in afr.

    Accel pedal % vs throttle %. Does this indicated the throttle not opening all the way? These are the non-sae sensor values. Additional throttle PID's are in the table view. My understanding was these 2 show if the ecm is shutting the blade.

    Is anything pointing to what is causing this KR? I've got very hard time believing it's real with the stock timing map, 55* air, stock boost, and some water/meth spraying.




    This was the test run to get afr dialed back in after adding meth injection. I've yet to move the sensor. That will happen before I get back to tuning. IAT's couldn't be anywhere near as high as indicated.

    Appreciate any tips. Still learning gen5. I've got some general guidelines for starting on the tq modeling, but I'd like to fully understand the logs first.

    m1.hpl

    m1.hpt

  2. #2
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    What are your mods? Log shows 12lbs of boost which isnt stock. Post your tune.

  3. #3
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    It actually is the stock pulley. Only thing I did was modify the bypass vlave.

    Stainless works 2" headers with !cats.
    Rotofab cai
    Snow methanol


    Tune is posted above.

  4. #4
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    What's your Lambda value at WOT? I finally stopped seeing KR at 20* with stock Knock sensor values after I leaned it out to .86 actual.
    2019 C7 ZO6 M7.

  5. #5
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    Quote Originally Posted by HeavyChevy305 View Post
    What's your Lambda value at WOT? I finally stopped seeing KR at 20* with stock Knock sensor values after I leaned it out to .86 actual.
    .82. That's interesting. I've read similar but not a consensus.

  6. #6
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    Yes bump your lambda to .84 and see if it clears the knock. I was getting some knock at .82 and leaning it out a bit fixed that.

  7. #7
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    .85 is considered safe on a LT4
    2019 C7 ZO6 M7.

  8. #8
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    Will be leaning it out to see what happens with the KR. What about the throttle opening and predicted tq?

  9. #9
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    I leaned mine out to .85 and seems to like it. For a few pulls it was .87 and seemed fine with that but not something I would do full time. Amazing how lean direct injection can run over port injection.

  10. #10
    I dynoed a 2019 like you mods 7 speed standard and it made 622rwhp on pump gas

  11. #11
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    I added flex fuel over the weekend and bumped the timing up. This car just rips. No traction even at 80mph

  12. #12
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    Quote Originally Posted by jsbaugh View Post
    I added flex fuel over the weekend and bumped the timing up. This car just rips. No traction even at 80mph
    How much total timing? Did you do the DSX low side as well?
    2019 C7 ZO6 M7.

  13. #13
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    My timing is around 22 but that is only on e30. I?m limited to about e40 on the stock fuel system. With just pump gas I can only run around 18 degrees of timing before I get some knock.

  14. #14
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    Exclamation

    So I went ahead and leaned it out to .85-.86. This log is closer to .84 in reality. Leaning it out to .86 didn't change much. A few questions if anyone cares to answer. I also desensitized the knock sensors a bit. Notes of changes:

    m2 = leaned out to .85 lambda
    decreased knock sensor levels some
    lowered kr attack rate as well
    ect vs retard changes
    5% add to peak engine tq above 2k rpm

    driver demnd last 2 rows x10% then last 4 x10% then last 5 by 10%
    copied driver deman A to all others
    3% added to peak tq
    on cutoff tab disabled "use predicted tq"
    disabled catalyst test on exhaust under eng diag
    desired eng coolant temp set to 185 under fans

    m3 = maf to get to .86 lambda


    1) Is the tq number recorded by the ecm a reflection of reality? I'd say I'm missing 100 ft-lb in that case. Surely this setup is 600+. 2" Headers, cai, single m15 meth, !cats. Show about 11-12psi.

    2) There are 2 pulls in this log. On the 2nd I see the throttle shut from 89 to 73. I see "predicted eng tq cmd" being flat as "max eng tq" takes a nosedive. Not sure precisely where that indicates a problem. It stole my timing as well. It didn't do on the pull right before. WTF? Car just got a little hotter. It was consistently doing it the next few pulls with more heat in the engine.

    3) Any thoughts on the MAT? My IAT2 stays steady or decreases through the run, but ECT climbs fast, and MAT follows. Should I even care? On any other car I'd read the sensors showing IAT with meth at 68* and ECT not even going over 205* and not pull any timing at all. Considering not pulling anything on IAT until 190.

    Appreciate any help. Log and tune posted below.

    m3.hpt

    m2.hpl

  15. #15
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    Did you adjust the VVE tables accordingly already? With your mods you shouldn't have to touch your Peak Torque or DD tables at all.
    2019 C7 ZO6 M7.

  16. #16
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    Quote Originally Posted by HeavyChevy305 View Post
    Did you adjust the VVE tables accordingly already? With your mods you shouldn't have to touch your Peak Torque or DD tables at all.
    Nope. I realized after some more reading that I've missed a step. Haven't found a guide that I understand about VVE yet though.