Results 1 to 7 of 7

Thread: VVE Tunning: Can anyone Give me an Opinion on my VVE Tables?

  1. #1
    Tuner in Training
    Join Date
    Feb 2017
    Posts
    10

    VVE Tunning: Can anyone Give me an Opinion on my VVE Tables?

    Wondering if anyone can check out my VVE tables and log and make sure im going in the right direction, while retuning this oversized cam.

    Im weird out by the huge jumps calculate coefficients make.

    Current Tune:
    aaron june 15 maf fail v5 VVE DROP.hpt

    Current Log:
    jun 1 v4.hpl

    Any pointers when Tuning VVE? PE and DFCO are both off. Here what i started with:
    aaron june 15.hpt

    Thats was from a year ago, trucks been mainly sitting since then. It also took me like 30 test runs to get it there( vs 4 this time), and I was proud of that at the time. Im disgusted now, learned alittle more, but know where near enough. Any help or tips would be greatly appreciated.

    Here is my current VVE table based on the first log and tune posted:
    aaron june 15 v6.hpt

    I multi the .10 and 400rpm tables by 90% then started interpolating from the mult by half % changes. Seemed to really stop the huge changes id get when calculating coefficients, and made it more inline with LTFT vs STFT data i had.
    Last edited by Aeddin; 06-24-2020 at 04:39 PM.

  2. #2
    Tuner in Training
    Join Date
    Feb 2017
    Posts
    10
    Also how long to wait before recording Fuel trims after rewriting VVE? ID say my main fault in the first tune was that I rewrote about 30-40 in the course of a weekend. IV only done it 5 times this week, and notice a much smoother VVE table, and more accurate data.

  3. #3
    Advanced Tuner
    Join Date
    Apr 2016
    Posts
    328
    If you expand the scale of your VVE chart out, it will show the trend that your coefficients are creating even in areas beyond where your engine will ever see. I have found that extending the scales will make apparent any bad trends that will affect even the areas that you do drive in, making it harder to get in line.

    Try the scale below for example, or even one of the predefined ones, and you will see how far off the coefficients would take you if your engine ever operated in these areas. You're actually going to -13,000 at 3400 rpm and 181 kpa. You may never hit that, but the formulas are skewed enough to get it there, which makes it difficult to match the areas that you are trying to adjust. Of course my stock cal goes to -1,500 in one area using the scale below.

    To adjust the scale, right click on the VVE chart, click Edit (for row and column), paste in the steps that you want to see. Keep in mind that your Editor will stay with those settings even if you open a different cal, the setting stays with the Editor. But you can change them back whenever you want. There are also pre-defined row/colums that you can select. This is what I was using when I opened your file.

    Row (map kpa)
    5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99 101 103 105 107 109 111 113 115 117 119 121 123 125 127 129 131 133 135 137 139 141 143 145 147 149 151 153 155 157 159 161 163 165 167 169 171 173 175 177 179 181

    Column (rpm)
    100 250 400 550 700 850 1,000 1,150 1,300 1,450 1,600 1,750 1,900 2,050 2,200 2,350 2,500 2,650 2,800 2,950 3,100 3,250 3,400 3,550 3,700 3,850 4,000 4,150 4,300 4,450 4,600 4,750 4,900 5,050 5,200 5,350 5,500 5,650 5,800 5,950 6,100

    If you see a ridiculous trend in the far ends of the VVE, you can manually correct that area so the Calc Coeff function is not stretching to hit bogus numbers. Others may say this is not necessary, I dunno, but it helped me find an ever-increasing skewing of numbers, off the scale where I couldn't see, that led to it getting harder to start. My changes skewed numbers around 100 kpa at cranking speed (approx 100 rpm), but I did not see these changes at the time as my scale started at 400 rpm.

    Can you run it on full MAF? If so, that may help you get VVE dialed in better, but you will need to log MAF g/s, VE g/s, and Dynamic g/s. Engine will run on Dynamic, which is based on MAF and VE, but you can see where either of those is off from each other. Also figure in your fueling error.

  4. #4
    Tuner in Training
    Join Date
    Feb 2017
    Posts
    10
    Thank you for the info.

    Main thing is getting this POS to idle the AC.

  5. #5
    Tuner in Training
    Join Date
    Feb 2017
    Posts
    10
    So using the Scale you posted, I should bump up the table after 145 KPA? Where it goes as far low as -7000? What would be best to put down there, data so far off not sure where to start.

    Do see the 91-103 kpa, in the 100 and 250 cells has a big dip. Can see how that has skewed some usable tables. I interpolated the dips out the 100 column, then smoothed the 100 and 250 colums up to 117. That cleaned it up alot and mad it more inline with my 400 column. JUst still not sure what to do after the 125 row.

  6. #6
    Tuner in Training
    Join Date
    Feb 2017
    Posts
    10
    So i forgot my ETC Scalar was off, still had the truck data and not the LS7. Did seem to clean up the idle alot, But still getting some pretty heavy oscillation only with A/C on in gear and reverse only.

    Also noticing its always very lean on a rewrite until a few miles of driving, thats normal?

    Here the latest log with the ETC Scalar changes.
    v14.hpl

    Still seems pretty far off. Any suggestions to speed up this procces?

  7. #7
    Tuner in Training
    Join Date
    Feb 2017
    Posts
    10
    Post o2 test was still on, and casting nipple on the intake broke.