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Thread: 33350 Injector Flow Rate Density Multiplier - odd at 30C ITT?

  1. #1
    Tuning Addict WS6FirebirdTA00's Avatar
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    33350 Injector Flow Rate Density Multiplier - odd at 30C ITT?

    Just looking through my tune and others, I see the injector flow rate density has some odd jumps. If you look at 30C there is a significant drop, indicating a drop in density at 30C for the injector tip.

    That seems odd, just curious if anyone has any insight here.

    I am still trying to mess with cold start, light load miss/hesitation/jerking feel. Some claim it is common on DI engines, I question plug heat range and octane cold and have also been trying to play with fueling and timing to see what I can find that will affect it. I am just looking through all the tables to see if I can find something helpful.
    Sulski Performance Tuning
    2000 WS6 M6 - LS6 (long block, refreshed top end), 10.8:1 CR, 90 mm ported FAST, Exo-Skel, 227/232 cam, QTP HVMC, EWP, GMMG, 9" w/4.11s
    2018 Sierra SLT 5.3L A8 - Airaid intake tube, GM Borla catback, L86 Intake/Ported TB

  2. #2
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    I have the same question
    I just started tuning the transmission on my 2018 sierra l83 6l80 and i noticed that it my ltft were pulling more fuel the longer it idled i found this table and thought it looked goofy

    Added injector tip temp to scanner and noticed it goes from 65c to about 95c after extended idle and the difference in that table was close to how much my ltft were changing with extended idle. i changed the whole table to 1 and it seems to have helped but i havent logged much yet and it could also be the ivt gain.

    just put the ivt gain to all 1 also and looks like my fuel trims are even closer i think i am going to leave them both 1, also seems to have made my idle smoother

    has anyone else tried adjusting these

  3. #3
    Tuning Addict WS6FirebirdTA00's Avatar
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    FYI, for my cold hesitation issues it turned out to be variable valve timing. I needed to reduce it until it warmed up to a little higher coolant temperature.

    I left this density multiplier as is for now. I can?t logically explain why they did it, but not knowing why I didn?t want to just change it.

  4. #4
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    All the fueling tables on my truck are still stock and by changing this table to 1 the difference between stock and 1 was how much my fueling is off and just happened to bring my trims to +-2
    I compared it to a corvette tune and they dont have the dip, and i found lingenfelter injector charesteristics and it looks like they use a smoothed out version of the corvette table so that is what i am going to use.

  5. #5
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    0.8250 0.8475 0.8675 0.8850 0.8950 0.9030 0.9120 0.9150 0.9175 0.9080 0.8950 0.8575 0.8100 0.7700 0.7450 0.7300 0.7300
    0.8550 0.8725 0.8900 0.9050 0.9175 0.9250 0.9325 0.9375 0.9400 0.9300 0.9200 0.8850 0.8350 0.8000 0.7750 0.7600 0.7600
    0.8800 0.8925 0.9075 0.9225 0.9350 0.9450 0.9520 0.9550 0.9600 0.9500 0.9400 0.9050 0.8600 0.8300 0.8000 0.7900 0.7900
    0.9000 0.9100 0.9250 0.9375 0.9470 0.9525 0.9600 0.9650 0.9700 0.9675 0.9550 0.9350 0.8950 0.8625 0.8300 0.8200 0.8200
    0.9100 0.9200 0.9350 0.9450 0.9500 0.9600 0.9650 0.9670 0.9720 0.9700 0.9550 0.9300 0.9000 0.8750 0.8400 0.8300 0.8300
    0.9275 0.9350 0.9450 0.9500 0.9550 0.9650 0.9700 0.9745 0.9740 0.9700 0.9590 0.9450 0.9200 0.8830 0.8500 0.8400 0.8400
    0.9450 0.9500 0.9550 0.9600 0.9675 0.9750 0.9800 0.9850 0.9850 0.9825 0.9750 0.9600 0.9400 0.9050 0.8750 0.8700 0.8700
    0.9550 0.9600 0.9650 0.9675 0.9700 0.9710 0.9720 0.9750 0.9770 0.9800 0.9750 0.9700 0.9600 0.9400 0.9100 0.9000 0.9000
    0.9650 0.9675 0.9700 0.9700 0.9720 0.9730 0.9750 0.9800 0.9800 0.9800 0.9775 0.9750 0.9700 0.9500 0.9300 0.9200 0.9200
    0.9725 0.9738 0.9750 0.9750 0.9773 0.9785 0.9800 0.9825 0.9838 0.9825 0.9823 0.9800 0.9775 0.9625 0.9400 0.9300 0.9300
    0.9800 0.9800 0.9800 0.9800 0.9825 0.9840 0.9850 0.9850 0.9875 0.9850 0.9870 0.9850 0.9850 0.9750 0.9500 0.9400 0.9400
    0.9900 0.9900 0.9900 0.9900 0.9913 0.9925 0.9930 0.9930 0.9943 0.9935 0.9945 0.9940 0.9900 0.9825 0.9563 0.9475 0.9475
    1.0000 1.0000 1.0000 1.0000 1.0000 1.0010 1.0010 1.0010 1.0010 1.0020 1.0020 1.0030 0.9950 0.9900 0.9625 0.9550 0.9550
    1.0000 1.0000 1.0000 1.0000 1.0000 1.0010 1.0030 1.0055 1.0070 1.0060 1.0045 1.0055 1.0000 0.9950 0.9713 0.9625 0.9625
    1.0000 1.0000 1.0000 1.0000 1.0000 1.0005 1.0025 1.0060 1.0090 1.0083 1.0095 1.0140 1.0110 1.0050 0.9900 0.9775 0.9775
    1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0020 1.0050 1.0065 1.0120 1.0200 1.0170 1.0100 1.0000 0.9850 0.9850
    1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0034 1.0008 1.0000 1.0000 1.0000 0.9963 0.9963