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Thread: ARRRGGGHHH VVE sux

  1. #1

    ARRRGGGHHH VVE sux

    Holy crap sd in VVE is taking forever! Coefficients seem to be screwing me up. Do any of you know how I can make it any easier? Also on the filters for graphs, do you need to include the original math in the calculation for the filter?

  2. #2
    wtf? HELP!

  3. #3
    Senior Tuner Ben Charles's Avatar
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    If you don’t want to mess with Coefficients, upgrade to 2 bar system and tune it like a traditional VE table

    Email Tunes, [email protected]
    96 TA Blown/Stroked, 4L80E/Fab 9
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  4. #4
    thanks mr Charles, am I just being impatient or is the 2 bar the better way? if I go 2 bar will I have to readjust idle and maf?

  5. #5
    I have to admit I was feeling pretty confident until I started on the vve. this is my first attempt and if it wasn't for this forum and utube I don't think I would have made it this far.

  6. #6
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    Just zero out ALL of the prediction coefficients (unless you are mostly stock). EDIT- predictions coefficients were really screwing with my WOT fueling. Once I zero'd ALL of the tables, it became fixable.

    I'll paste my filters that I use later tonight.

    I felt overwhelmed when I first started VVE, but a little work and frustration up front is part of it, I think. Also know that once you get it to within 3-4% of target across the map, that's about as good as you'll get. It's still just a bunch of equations/surfaces netted together when all is said and done. It's easier to get MAF to be very tight and repeatable, but VVE will be a little more loose.
    Last edited by RobZL1; 08-01-2019 at 03:22 PM.

  7. #7
    Senior Tuner Ben Charles's Avatar
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    2 bar on e38 uses MAF or SD or blend of the 2..

    Seems like you want to keep it blended so that’s no problem..

    Email Tunes, [email protected]
    96 TA Blown/Stroked, 4L80E/Fab 9
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    14 Gen 5 Viper
    Custom Mid Engine chassis, AKA GalBen C

  8. #8
    thank you, its a 4.8 with the 228/230 cam and the cells on the vve are way different than stock, so its like i'm starting from scratch. yes id like to keep it blended for now. I felt I needed to learn the sd because id like to go boosted maybe in the winter $$$$? as far as the filters go I built one but did not include the original graph math in the filter math-should I?(did that make sense)

  9. #9
    Senior Tuner Ben Charles's Avatar
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    Always make sure the axis (column and rows) match your scanner...

    One of the first things I do is copy labels to make sure that’s correct..
    Otherwise never be right and you’ll chase your tail

    Email Tunes, [email protected]
    96 TA Blown/Stroked, 4L80E/Fab 9
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  10. #10
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    I'm not sure what you mean by "include the original graph math in the filter math."

    All you need to do is put the filter criteria in the function box- see attached photo. Here's the one I use for VVE, just copy and paste:
    ([6310]<7 OR ([6310]<15 AND [6310]>7)) AND [6215.242]<135 AND [6215.242]>118 AND [2146.242]>305 AND [50090.156.slope(3000)]<1 AND [50010.242]>187

    filter.jpg

    Here is a rundown of the filters:

    [6310]- filters on Fuel Trim Cell. I'm not sure which ECU you have, so you may have to change the values. For my later e67, this filter eliminates deceleration for both EVAP open and EVAP closed. 0-5 are trim cells for throttle applied, 6 is idle, and 7 is decel. 8-13 are trim cells for throttle applied, 14 is idle, and 15 is decel. 0-7 are EVAP open (purging into intake), and 8-15 are EVAP closed (not purging into intake). When I tune open loop with the wideband, my e67 stays in cells 8-15, so it makes it a little more consistent without the EVAP gases adding to fueling. If I use fuel trims, it will usually be EVAP open once fully warmed up. I find it easier to tune with a wideband in open loop, personally.

    [6215]- filters on Injector Tip Temperature. You will need to adjust the values for your vehicle based on where it typically runs. If you have stock injectors, or an ECU with zero'd injector tip temp offset, then it's less of a big deal. ITT influences part throttle fueling significantly if the offset is not correct in the tune, thus it helps to filter a range where your vehicle typically runs, then get ITT offset correct later.

    [2146]- filters on Intake Valve Temp. This ensures the vehicle is up to temperature. You will likely need to change the value to suit your normal running IVT.

    [50090]- filters on throttle position. This ensures that the throttle input has changed less than 1 percent for 3 seconds (3000 milliseconds) before the data "counts"

    [50010]- filters on coolant temperature. Just another one to ensure the vehicle is up to temp- can use this instead of IVT, actually (or oil temp might be even better than both)

    That's how I do it. I also do another one that filters the same except shows only FTC's 15 and 7 for deceleration. Sometimes I also pull a separate table for only FTC's 6 and 14 for idle.

    It's also beneficial to look at EQ error vs ITT, just to see how far out of whack your ITT offset might be. See attached photo for LTFT+STFT vs ITT after flashing at operating temperature. You'll see that trims are fairly close to each other. I really care about anything under 160, because that's where my car will run under normal usage. So I have dialed that in pretty well so that the fueling is close to the same up to 160. Past 160, I just wanted to make sure it was pulling fuel.

    ITT.jpg

  11. #11
    awesome thanks RobZL1 I think my brain is oozing from my ears but i'm going to work off what you've given me. this afternoon I swapped over to the 2 bar os and I cant seem to keep the truck running long enough for it to command lambda=real lean? its not temp related it seems to be time related, lastly the IMRC tables were zeroed out, so do I add from the log in order to populate the cells? please keep in mind this is my first attempt, but I'm invested and determined to learn this

  12. #12
    oh e38 btw

  13. #13
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    I believe you need to populate all of the VE tables in the 2 bar with the same data (no real experience there- I'm sure Ben can tell you the proper method). I also think the axes might be transposed compared to the VVE table in the stock OS, so be sure to flip them in excel first. Again- not experienced with 2-bar, so Ben is probably the better guy to listen to here. Filters should still apply, though.

  14. #14
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    Quote Originally Posted by RobZL1 View Post
    I'm not sure what you mean by "include the original graph math in the filter math."

    All you need to do is put the filter criteria in the function box- see attached photo. Here's the one I use for VVE, just copy and paste:
    ([6310]<7 OR ([6310]<15 AND [6310]>7)) AND [6215.242]<135 AND [6215.242]>118 AND [2146.242]>305 AND [50090.156.slope(3000)]<1 AND [50010.242]>187

    filter.jpg

    Here is a rundown of the filters:

    [6310]- filters on Fuel Trim Cell. I'm not sure which ECU you have, so you may have to change the values. For my later e67, this filter eliminates deceleration for both EVAP open and EVAP closed. 0-5 are trim cells for throttle applied, 6 is idle, and 7 is decel. 8-13 are trim cells for throttle applied, 14 is idle, and 15 is decel. 0-7 are EVAP open (purging into intake), and 8-15 are EVAP closed (not purging into intake). When I tune open loop with the wideband, my e67 stays in cells 8-15, so it makes it a little more consistent without the EVAP gases adding to fueling. If I use fuel trims, it will usually be EVAP open once fully warmed up. I find it easier to tune with a wideband in open loop, personally.

    [6215]- filters on Injector Tip Temperature. You will need to adjust the values for your vehicle based on where it typically runs. If you have stock injectors, or an ECU with zero'd injector tip temp offset, then it's less of a big deal. ITT influences part throttle fueling significantly if the offset is not correct in the tune, thus it helps to filter a range where your vehicle typically runs, then get ITT offset correct later.

    [2146]- filters on Intake Valve Temp. This ensures the vehicle is up to temperature. You will likely need to change the value to suit your normal running IVT.

    [50090]- filters on throttle position. This ensures that the throttle input has changed less than 1 percent for 3 seconds (3000 milliseconds) before the data "counts"

    [50010]- filters on coolant temperature. Just another one to ensure the vehicle is up to temp- can use this instead of IVT, actually (or oil temp might be even better than both)

    That's how I do it. I also do another one that filters the same except shows only FTC's 15 and 7 for deceleration. Sometimes I also pull a separate table for only FTC's 6 and 14 for idle.

    It's also beneficial to look at EQ error vs ITT, just to see how far out of whack your ITT offset might be. See attached photo for LTFT+STFT vs ITT after flashing at operating temperature. You'll see that trims are fairly close to each other. I really care about anything under 160, because that's where my car will run under normal usage. So I have dialed that in pretty well so that the fueling is close to the same up to 160. Past 160, I just wanted to make sure it was pulling fuel.

    ITT.jpg
    Your last statement regarding the ITT temp going past 160 and pulling fuel, aren't you wanting to ADD fuel when it gets hotter? I have read that zeroing this table out when it was previous populated is very bad because after heat soak you will be running lean with a zero'd out table.

  15. #15
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    Quote Originally Posted by sgod1100 View Post
    Your last statement regarding the ITT temp going past 160 and pulling fuel, aren't you wanting to ADD fuel when it gets hotter? I have read that zeroing this table out when it was previous populated is very bad because after heat soak you will be running lean with a zero'd out table.
    I just meant that I didn't want trims to be adding fuel if I went WOT at a higher ITT.

    Regarding leaning it out, there's a middle point. Zeros in the table will lean it out and the trims will add fuel in closed loop. Stock values will add too much fuel and trims will be very negative in closed loop. I just wanted to tune mine to where it had roughly the same negative trims in closed loop as normal operation. Also, at WOT in open loop, I did pulls at all temp ranges from 200 down to operating temp to ensure WOT fueling was not affected. That's the most important thing in my opinion- at the higher temps, ensure WOT fueling is still correct.
    Last edited by RobZL1; 08-02-2019 at 08:30 AM. Reason: Got positive and negative trims backwards...doh!

  16. #16
    Rob thanks for the info. I feel more familiar with the VVE because ive been working on it so much but changed to 2bar yesterday and I'm going to stick with it because ill need it when I go forced induction. Are you saying the "numbers" in the VVE table can be used to populate the 2bar ve table?

  17. #17
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    Quote Originally Posted by RobZL1 View Post
    I just meant that I didn't want trims to be adding fuel if I went WOT at a higher ITT.

    Regarding leaning it out, there's a middle point. Zeros in the table will lean it out and the trims will add fuel in closed loop. Stock values will add too much fuel and trims will be very negative in closed loop. I just wanted to tune mine to where it had roughly the same negative trims in closed loop as normal operation. Also, at WOT in open loop, I did pulls at all temp ranges from 200 down to operating temp to ensure WOT fueling was not affected. That's the most important thing in my opinion- at the higher temps, ensure WOT fueling is still correct.
    Gotcha, that makes sense. I just wanted to make sure I wasn't confused on this. Thanks