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Thread: Coyote with Roush, tuning HELP!

  1. #21
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    Quote Originally Posted by Eric@HPTuners View Post
    If you are return style, the inferred fuel pressure should be set to whatever you set the fuel pressure to (vacuum off) as this is the delta pressure, not gauge pressure.
    So delta pressure is the effective fuel pressure at the injector when factoring in the pressure from the blower working against the injector. That means all cells should be 55(my base fuel pressure)?

  2. #22
    HPT Employee Eric@HPTuners's Avatar
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    Quote Originally Posted by Witt View Post
    I'm also under the assumption that the Fuel Flow values in that table aren't actually fuel flow but engine rpm in thousands. Am I correct in thinking that or did I pick up something outdated in researching this?
    I'm not sure where you got that from. The pressure drop is modeled, based on fuel flow.

    Quote Originally Posted by txcharlie View Post
    So delta pressure is the effective fuel pressure at the injector when factoring in the pressure from the blower working against the injector. That means all cells should be 55(my base fuel pressure)?
    Correct.
    Eric Brooks
    HP Tuners, LLC

  3. #23
    Advanced Tuner Witt's Avatar
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    Quote Originally Posted by Eric@HPTuners View Post
    I'm not sure where you got that from. The pressure drop is modeled, based on fuel flow.
    From another software company.

    http://i.imgur.com/entO1Ih.jpg

  4. #24
    HPT Employee Eric@HPTuners's Avatar
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    That description is inaccurate for the 2011+ Mechanical returnless. It is accurate for the older Fords that had a similar system.
    Eric Brooks
    HP Tuners, LLC

  5. #25
    Advanced Tuner Witt's Avatar
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    Quote Originally Posted by Eric@HPTuners View Post
    That description is inaccurate for the 2011+ Mechanical returnless. It is accurate for the older Fords that had a similar system.
    Ok, I kinda had that in the back of my head which is why I was asking if the info was outdated, thanks for clarifying that for me.

  6. #26
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  7. #27
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    Quote Originally Posted by Eric@HPTuners View Post
    If you are return style, the inferred fuel pressure should be set to whatever you set the fuel pressure to (vacuum off) as this is the delta pressure, not gauge pressure.
    Thanks for straightening me out.

  8. #28
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    Now that I know the fuel system and injectors are setup correctly, I'm trying to get the MAF transfer as accurate as possible. I am logging with SCT Livelink, which logs in frequency. I convert the frequency to time in order to know which cells to adjust.
    I am doing idle/rev logs at the moment, using inverted STFT average to find correction factor. If I understand correctly, a STFT below 1 means lean and above 1 means rich. My logs show that I'm between 9% and 21% lean from periods 525 to 288. Up to 288, the LTFT was steady at 1 and at 277 it starts running below 1 and at the same point my STFT starts to run about 7% rich.

    Is this where the pcm starts making corrections with LTFT based on STFT readings?
    I have not put many miles on the tunes after loading. Should I put more time/miles on the tune to let the PCM make adjustments with adaptive learning or is it better to make the adjustments immediately after loading tune?

  9. #29
    Advanced Tuner Witt's Avatar
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    Quote Originally Posted by txcharlie View Post
    Now that I know the fuel system and injectors are setup correctly, I'm trying to get the MAF transfer as accurate as possible. I am logging with SCT Livelink, which logs in frequency. I convert the frequency to time in order to know which cells to adjust.
    I am doing idle/rev logs at the moment, using inverted STFT average to find correction factor. If I understand correctly, a STFT below 1 means lean and above 1 means rich. My logs show that I'm between 9% and 21% lean from periods 525 to 288. Up to 288, the LTFT was steady at 1 and at 277 it starts running below 1 and at the same point my STFT starts to run about 7% rich.

    Is this where the pcm starts making corrections with LTFT based on STFT readings?
    I have not put many miles on the tunes after loading. Should I put more time/miles on the tune to let the PCM make adjustments with adaptive learning or is it better to make the adjustments immediately after loading tune?
    The fuel trims are like a GM, they show you percent corrected. Simply multiply the trim by that maf cell. If your trim shows a .95, its pulling 5% due to a rich condition.

    Older Fords used the inverse as a correction factor, Coyotes log a direct correction.

  10. #30
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    So a .95 STFT and .95 LTFT mean the same thing? Both are 5% rich? This is only on Coyote?
    Last edited by txcharlie; 03-06-2015 at 01:25 PM.

  11. #31
    Advanced Tuner Witt's Avatar
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    Quote Originally Posted by txcharlie View Post
    So a .95 STFT and .95 LTFT mean the same thing? Both are 5% rich? This is only on Coyote?
    Yes, a .95 would be logging a rich condition and require your MAF value to be reduced in that cell.

    I find it best to disable LTFT temporarily and log STFT vs MAF.

  12. #32
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    Thanks Witt! I've learned a lot from all the help I've received on this forum. I hope I can learn enough to help someone else out one day. But at this point, I'm very NEEDY....