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Thread: Exhaust valve closing angle

  1. #1
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    Exhaust valve closing angle

    2014 V6 stang

    while playing with overlap for Ghost tune i notice odd angle progression Vs RPM.
    see chart
    valve timing.jpg


    Why the zero on 10 and 13?

    Did ford make a mistake?

    I would think this would be a linear progression from load o through 14. what am I missing?

    Thanks,
    Greg

  2. #2
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    No. Ford did not mess up. You're looking at EVC, the IVO is advancing in these mapped points. These MP are mainly used in deceleration or in optimum stability. Advancing IVO reduces pumping losses, it reduces or lowers the momentum/inertia of rotation by allowing more fresh air in, increasing cylinder pressure to stabilize cylinder conditions. IVO, is important, the real effect and more important part of the valve events is IVC.

    Some of the MP can be disabled or aren't used. But that's a little explanation.

  3. #3
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    What would you recommend to get more lope and less surge?

    Thanks...

  4. #4
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    Cool

    Quote Originally Posted by hamiltog View Post
    What would you recommend to get more lope and less surge?

    Thanks...
    Nevermind... I figured it out when I remember what I used to do be in highschool day when we ran bigger cams. Bumped up Idle and pushed overlap in MP1,2,3. I have more chop/lope and less surge now like you would get if you had a roots blower.

    Thanks white 50 for your all your help.. I'm still reviewing your writeup up on distance table.I think I'm starting to get it. I can see I have much to learn...

  5. #5
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    Yes, you need to increase overlap at idle. You dont need to use 3 MP. You will waste more fuel at idle and could end up causing P0300. It is possible to keep fuel economy while driving by using MP0 only for the ghost cam. You'll need to try different cam angles and idle RPMs. You can start by increasing idle to 900. Increase idle max to 1000. In idle > general, below rpm error enable and disable is VSS min. Set it to 0 to reduce torque control. Change IVO for MP 0 to -40* and EVC for MP 0 to 10*. Look at your intake max and exhaust max tables and change them to allow your requested degrees at idle RPM. Check intake/exhaust combustion stability angles as well.
    0 out optimal stability mapped point and 0 out emission reduction mapped point.
    Open VCT fuel economy and change top left, 2x2 cells value to 0. If you have 0 any where else in the table. Change it to a 1.

    Thats a start.

  6. #6
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    Hey white 50, I tried out your suggestion but can get lope to occur until I move EVC for MP 0 to >18-20*, 10* just doesn't cut it. If I have MP 0 to -42* and EVC for MP 0 to 22* I get a nice lope but accompanied with surge regardless of what base RPM I use. Trying to avoid using MP3 I'v trimmed down to
    MP 0 to -42* and EVC for MP 0 to 22*
    MP 1 to -35* and EVC for MP 0 to 15*
    But still get some minor surge.

    I did play with experiment with disabling torque management but could not get Idle lower ant 1K and lost all lope and surge. I re-enabled torque management and tried playing with MP0 torque table RPM cells 550, 1000 but to no avail. I did return back to stock I think but got the check traction control failure lights this morning after tuning last night. what did I do???

  7. #7
    One thing that I was able to do was use more mild cam angles for lope and lower the spark in that load/rpm area for that mapped point. That seemed to help it be more stable and it chopped harder with lower ignition advance. I used to have a totally flawless lope tune on my 2013 gt, but it took a lot of screwing around and experimenting with to make it right. Then I rarely used it when it was finished lmao.

  8. #8
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    Thanks for the suggestion Matt, I'll try playing with timing those MP's. I see, lowering timing will make it more lazy and perhaps less corrective and so reducing surge. I agree on the usefulness of this exerciser. After I've succeeded in getting a nice old fashion lope that is stable and has not effected driveability by much my next goal is to move on to more productive matters and start tuning fuel and timing to optimize use of the shorty headers, X pipe cold air intake. I do see some lean spots in my fuel trims log that could be addressed. Now I have to figure out the how to to fix these.

  9. #9
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    Quote Originally Posted by mattlinke View Post
    One thing that I was able to do was use more mild cam angles for lope and lower the spark in that load/rpm area for that mapped point. That seemed to help it be more stable and it chopped harder with lower ignition advance. I used to have a totally flawless lope tune on my 2013 gt, but it took a lot of screwing around and experimenting with to make it right. Then I rarely used it when it was finished lmao.
    ^^^ All of this exactly lol! You don't need huge overlap to make a nice sound, lower timing helps, and a bit of driveability tuning. I got it near perfect with an auto+cats and none of the side effects (rich, stalling, etc) that are common. Then I had it on there for a day or so and went back to stock lmao. I just want it in my back pocket if I want it to sound bada$$ for a day
    2014 Mustang GT Premium. 4C & Borla Exhaust
    "Don't fix it if it ain't broken"

  10. #10
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    BlackBolt, your spot on with sound bada$$ for a day Just something about that rumpty rumpty idle that makes me LOL like a school girl. That unrefined sound is like an old leather jacket...

    To make you laugh more..... I explained to the wife what I'm doing and explained the short coming of the old single cam design of old and how the new system of today gives you the best worlds of smooth operation but high output at the same time and she said

    "So you want to take your advanced technology car and make it sound old and low tech" " I though you bought this software package to increase the performance of your Mustang???"

    My response...

    Why yes Dear that's just what i'm doing.. For now

    So would you mind helping me out with some the specifics of you accomplished your recipe?
    Last edited by hamiltog; 4 Days Ago at 11:14 AM.

  11. #11
    The premise as i remember it was pretty straightforward

    Log your idle and low cruise air load (where the load is going to be as low as its going to be in both situations).
    Set the stability table to the MP that you want it to lope in at the RPM you idle at, slightly above and below and above the idle RPM, a different MP. (i always picked 0 just because it made the most sense to me and i set MP 0 to like -20, 25 or something like that. i could get it to really chop at like -35, 35).

    Using the example of (MP0 = lope MP) I had that car idling at 1000rpm. so i then made the column axis like 500, 900, 1200, 1300, 2500, 4000 or something. i set columns 500 and 900 to MP0 and then the rest to 1 i think.

    I then set the load scalar on the fuel econ table to where anything less than light cruise load was the load it idled at. Say it idled at .13 and it cruised at .16. I set the top row to .14 so anything less was going to be in that cell and not interpolate. then the row below was .15. then i set the rpm that i idled at in that table to seek MP0 (in case it was coming to idle and somehow using the econ table)

    THEN i made sure it did like i wanted. Idle with chop in the angle i wanted and as soon as i would touch the throttle it would go off that MP and move to something stable. and NEVER come back till it was going to idle again. took some slow driving and things to really nail down the loads that determined idle from driving. rinse and repeat as many times as needed till you're happy with it.

    Basically my car NEVER drove in MP0. just idle.

    once i was satisfied with that I went into the Borderline spark table for MP0 and at the idle area i think i put 10* there. then i smoothed it so there wasn't a dramatic change in spark (say from 10 to 50). This made the biggest difference in the sound. It chopped way harder with less timing.

    As far as making it stay running and be smooth I can't remember all the things I did. I touched a lot of tables. Idle airflow, reaction lambda after OL (.85 i think was stock and if it would dfco too close to the choppy idle it would start fueling again and die sometimes, i think i ended with that around .95 or something. I may have messed with the TQ tables too but I cannot remember.

    I spent a lot of time on it but when i was done all you had to do was look at the throttle sternly and it would stop loping and be smooth. I also did this using ford LU80 injectors which never cooperated well at lower pulsewidths so its possible i had to do a bit more than some setups will require.

    Thats straightforward right?
    LOL

  12. #12
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    Smile

    Hey Matt,

    Thanks for sharing your perspective on settings you used in the past to create a lopey idle. When you think about the root cause of idle lope is all comes down to combustion instability. Big cams in the single cam engine produced exhaust gas contamination and inconsistent vacuum signal to the carburetor so fuel mix was not consistent. All this created a mix/oscillation of slow/fast flame front travel.

    I guess I've been talking the old school approach by creating overlap but just at the idle region. I suppose if I had access to a PID loop I could alter the stability oscillating between very lean to stoch and could create the same effect. I did think about this a few day ago, but I could not find a PID loop like the GM operating system seem to have from the posts I?ve seen in their camp.

    Can this be commanded in the TQ tables by dithering a about a MP borderline?
    Is that what you were attempting to do?

    You wouldn?t still have that tune kicking around would you? I?d love to poke around to see the missing points you didn?t remember.

    Fun stuff! You?re right, straightforward once you understand the physics of what?s going on.

    Where I?m at now is trying to understand the tools I have at my disposal within the HP platform. Still learning?

    Thx