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Thread: Virtual torque model

  1. #1
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    Virtual torque model

    Ok so I feel like I have a decent grasp on the torque model but just wanted to start a thread on it again. I have read a ton of stuff that seems like Ghuggins and Higgs are always on. I have seen people just say to raise the airmass a b c d. And then I see people that suggest actually editing the torque model under the edit tab. Which when it gets edited it changes the airmass a rpm a map a ect under the coefficients tab. My question is. Let?s use for example a cammed g8 with headers. I always try to keep the maf curve above stock. Which raises delivered engine torque. The scanner shows a increase in delivered engine torque and the shifts feel good and hit my commanded shift time around .200.at wot. But I am curious if I am losing anything when it comes to how it drives ect by not correcting the torque model on a cam bolt on car. And if so how should I get it correct. It seems like on the gen 4 stuff the only way to do it is log engine torque and set it up to mimic the torque model table and filter through the -10-40 timing points. Or am I better by logging engine torque and comparing it to the torque model and multiplying the percentage it?s off to the airmass and map tables. The reason I?m asking is because if I multiply the airmass tables by 15-20% my delivered torque goes up into unrealistic ranges with the maf curve raised above stock already.
    Last edited by rptuning1; 12-03-2018 at 03:07 PM.

  2. #2
    Tuner evolmotorsprt's Avatar
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    This is a good topic that I'd like info on as well. Bump

  3. #3
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    I am mainly curious on how most edit the model. Whether they just edit the airmass a b c d by the percent they believe they need to get the model correct and then hand smoothing under the edit>virtual torque after tuning the engine side. Or if they do it all under the edit>virtual torque by logging engine torque in a chart that mimics the virtual torque model and inputting the values after tuning the engine side and fueling is made correct.

  4. #4
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    I am no expert but on my car I increased the airmass by the approx. percentage that torque has increased over stock. Never had an issue doing it that way.
    2007 Corvette C6 Vert. A6
    LME LS402, Pat G custom cam, ATI 10% OD Damper
    Circle D triple disc 2600, 3.42 Diff
    YSI, 3.0 pulley, ID 1000's
    Alky Control Meth,
    ARH 1 7/8 headers,
    1009 RWHP @ 7000, 817 RWT @ 6000

  5. #5
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    Yes me and you have talked on fb before I believe a while back. I have done that several times also with no negative results. I have just been reading a ton of info on the subject. I’ve gotten curious how 99% of the successful 6l or 8l people adjust the torque model. Whether they do it all under the edit>virtual torque or if they mostly use the coefficient tables in the tune and then just use the virtual torque to visualize. Or if they use alittle but of both.
    Last edited by rptuning1; 12-04-2018 at 09:08 AM.

  6. #6
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    Bump for any other info.

  7. #7
    The vve calculates coefficients for you, if you are adjusting the coefficients aren't you just doing extra work? From personal experience I adjust the vve and let it calculates the coefficients. Also ask yourself this, in speed density I only adjust the ve tables, I've never even noticed coefficient tables when in my custom sd os. I am not an expert but what's the advantage of trial and error with each coefficient table, vs adjusting vve and letting it do the calculations for you? My trims are all negative 1-3% and I let the vve calculates coefficients after I adjust the vve table against my histogram a few times. Then I just go sd because I prefer it. That my .02 cents

  8. #8
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    I am referring to vIrtual torque coefficients. Not virtual ve. The coefficients I am referring to are under the torque model tab.

  9. #9
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    This discussion is more about how/when to dial in the torque model correctly.

  10. #10
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    ^^ This. Especially on a Gen4 E38 that doesn't have the Driver Demand issues the Gen5 guys have. It it even necessary to adjust? The throttle and trans seem to do just what I tell it, without changing the Virtual Torque charts.

  11. #11
    Bump. Would like to have some more informed discussion on this. I understand that this is probably/possibly used for torque management calculation, AC Torque calculation, Delivered Torque (to the transmission/TCM) and GHuggins has mentioned timing and throttle progression in light throttle. My E67 ('08 TBSS) torque model seems like its already pretty in line with reality for a given spark and MAP. What benefit is there to adjusting virtual torque model in a stock engine? I don't see a slightly more accurate model helping the torque management or AC torque much (at least from driver perspective). Is there any more detailed info on how and what the torque model can and does effect or is it all trial and error at this point?

  12. #12
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    Bump for more info on the subject as well.

  13. #13
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    Another bump, this is interesting!