Page 1 of 2 12 LastLast
Results 1 to 20 of 27

Thread: 2015+ Driver Demand Requests not Matching Table

  1. #1
    Senior Tuner CCS86's Avatar
    Join Date
    Nov 2017
    Location
    Austin
    Posts
    1,089

    2015+ Driver Demand Requests not Matching Table

    Hi guys,

    I have done a lot of Driver Demand tuning on the earlier cars 2011-2014, and the logged ETC TQ Request table has always matched a lookup of my Driver Demand table for a given pedal position and RPM.

    On this 2015 I'm working on, that is not the case. For example, at 4000 rpm and 73% pedal, my DD table calls for 500 ft-lbs, but the ETC TQ request logs as 252 ft-lbs.

    • There are no DD limits active
    • TQ Source = DD
    • Throttle angle source = TQ control


    What am I missing here?

  2. #2
    Senior Tuner CCS86's Avatar
    Join Date
    Nov 2017
    Location
    Austin
    Posts
    1,089
    Look at how flat the ETC TQ request is (mirrored by desired load), while the pedal position steeply increases:

    dd tq req.jpg

  3. #3
    Senior Tuner CCS86's Avatar
    Join Date
    Nov 2017
    Location
    Austin
    Posts
    1,089
    Here the ETC TQ Req actually drops as the pedal gets rolled on:

    dd tq req2.jpg

  4. #4
    Senior Tuner CCS86's Avatar
    Join Date
    Nov 2017
    Location
    Austin
    Posts
    1,089
    Log section of a roll-on:
    Attached Files Attached Files

  5. #5
    Senior Tuner CCS86's Avatar
    Join Date
    Nov 2017
    Location
    Austin
    Posts
    1,089
    No ideas?

  6. #6
    Advanced Tuner
    Join Date
    Feb 2016
    Posts
    482
    is this a boosted car?

  7. #7
    Senior Tuner CCS86's Avatar
    Join Date
    Nov 2017
    Location
    Austin
    Posts
    1,089
    It is.

    Here is what a roll-on looks like on a boosted, pre 2015 car. You can see that the TQ request follows the pedal position:

    roll-on tq-req.jpg

  8. #8
    Senior Tuner CCS86's Avatar
    Join Date
    Nov 2017
    Location
    Austin
    Posts
    1,089
    I thought I had found the issue in these tables:

    TQlimit.jpg

    But after maxing them out, the behavior is the same.

    My ETC TQ requests peak at about 300 ft-lbs and 50% pedal. From there, they level off and drop.

    I could really use some help on this!

  9. #9
    Senior Tuner CCS86's Avatar
    Join Date
    Nov 2017
    Location
    Austin
    Posts
    1,089
    Can anyone with S550 logs take a look and see if they get ETC TQ Requests above ~300 ft lbs?

    I'm stumped.

  10. #10

    Over 300torque

    You gave me a good excuse to go romp on my car... Roush 727. Here ya go with the log buddy
    Attached Files Attached Files

  11. #11
    Senior Tuner CCS86's Avatar
    Join Date
    Nov 2017
    Location
    Austin
    Posts
    1,089
    Quote Originally Posted by Ranger Coyote View Post
    You gave me a good excuse to go romp on my car... Roush 727. Here ya go with the log buddy


    Much appreciated Ranger!

    You are definitely getting full ETC TQ Request. Is your car stick or auto?

  12. #12
    It's auto. I'm running E85, ID1000 injectors w/ a return style. Roush 727 CAI & 80mm pulley

  13. #13
    Senior Tuner CCS86's Avatar
    Join Date
    Nov 2017
    Location
    Austin
    Posts
    1,089
    Still haven't been able to resolve this issue and hate using WOT start/end to force the blades open.

  14. #14
    Advanced Tuner
    Join Date
    Apr 2018
    Posts
    605
    Quote Originally Posted by CCS86 View Post
    Still haven't been able to resolve this issue and hate using WOT start/end to force the blades open.
    I am wondering why that car seems low on power, air load is low, and why is ETC throttle angle error -25? , all @ WOT ? I'm guessing all related to this problem..

    My impression is different and it is that as RPMs increase the ETC TQ request decreases which makes me think of some limit like air or fuel flow limit? I know you said it decreases as pedal increases however there's a point where the pedal is 100% and the RPMs are rising/TQ request is still falling slowly.
    Knock Retard is the reduction or prevention of knock by lowering ignition timing:

    (+) Adding Knock Retard = Reducing Timing. PCM is seeing knock.
    (--) Lowering Knock Retard = Increasing Timing. PCM isn't seeing knock.
    __________________________________________________ ________

    2014 Mustang GT Premium. VMP Gen2R Supercharged with an FTI 3000rpm Converter. JLT, BMR, Steeda, Viking, etc.
    Don't fix it if it ain't broken | Maximum effort gets maximum results

  15. #15
    Senior Tuner veeefour's Avatar
    Join Date
    Oct 2016
    Location
    Poland
    Posts
    1,712
    Try to set your WOT threshold like this 30/70. This way it ignores DD completely - this has some pros and cones unfortunately.

    It's a quick way to fix many issues, used by many beginner tuners...it does not solve everything tho...

    dd.jpg

  16. #16
    Senior Tuner CCS86's Avatar
    Join Date
    Nov 2017
    Location
    Austin
    Posts
    1,089
    Quote Originally Posted by blackbolt22 View Post
    I am wondering why that car seems low on power, air load is low, and why is ETC throttle angle error -25? , all @ WOT ? I'm guessing all related to this problem..

    My impression is different and it is that as RPMs increase the ETC TQ request decreases which makes me think of some limit like air or fuel flow limit? I know you said it decreases as pedal increases however there's a point where the pedal is 100% and the RPMs are rising/TQ request is still falling slowly.


    The load does seem a little bit low, but I don't know exactly how much boost this car is making. Probably only 9 psi or so. It is running a JLT MAF (which I am not a fan of). It is using MU52 injectors, which I have good data for, so I am using a scaled GT500 MAF curve.

    I think the ETC angle error is coming from the low WOT start point forcing the blades open compared to a low desired MAF/load/TQ.





    Quote Originally Posted by veeefour View Post
    Try to set your WOT threshold like this 30/70. This way it ignores DD completely - this has some pros and cones unfortunately.

    It's a quick way to fix many issues, used by many beginner tuners...it does not solve everything tho...

    dd.jpg



    That is the approach I am currently taking. It makes it driveable (and less of an issue on an auto car), but far from ideal, so I really want to sort it out.

  17. #17
    Advanced Tuner
    Join Date
    Apr 2018
    Posts
    605
    Quote Originally Posted by CCS86 View Post
    The load does seem a little bit low, but I don't know exactly how much boost this car is making. Probably only 9 psi or so. It is running a JLT MAF (which I am not a fan of). It is using MU52 injectors, which I have good data for, so I am using a scaled GT500 MAF curve.

    I think the ETC angle error is coming from the low WOT start point forcing the blades open compared to a low desired MAF/load/TQ.
    What kind of blower setup is it using? I was thinking same thing about why angle might be so off.
    Knock Retard is the reduction or prevention of knock by lowering ignition timing:

    (+) Adding Knock Retard = Reducing Timing. PCM is seeing knock.
    (--) Lowering Knock Retard = Increasing Timing. PCM isn't seeing knock.
    __________________________________________________ ________

    2014 Mustang GT Premium. VMP Gen2R Supercharged with an FTI 3000rpm Converter. JLT, BMR, Steeda, Viking, etc.
    Don't fix it if it ain't broken | Maximum effort gets maximum results

  18. #18
    Senior Tuner CCS86's Avatar
    Join Date
    Nov 2017
    Location
    Austin
    Posts
    1,089
    It's an M122 with a 2.75" pulley.

    Whatever the issue is, it is specific to something 2015+. I have the earlier PCM's driver demand systems working very well.

  19. #19
    Senior Tuner veeefour's Avatar
    Join Date
    Oct 2016
    Location
    Poland
    Posts
    1,712
    Quote Originally Posted by CCS86 View Post
    That is the approach I am currently taking. It makes it driveable (and less of an issue on an auto car), but far from ideal, so I really want to sort it out.
    Of course, and it will cause automatics to not work properly. The solution is to tune your Torque Model.
    It doesn't have to be right but TB model needs to follow DD - takes time. Sometimes it's better to change DD instead messing with TB model.

  20. #20
    Senior Tuner CCS86's Avatar
    Join Date
    Nov 2017
    Location
    Austin
    Posts
    1,089
    Quote Originally Posted by veeefour View Post
    Of course, and it will cause automatics to not work properly. The solution is to tune your Torque Model.
    It doesn't have to be right but TB model needs to follow DD - takes time. Sometimes it's better to change DD instead messing with TB model.



    Having an inaccurate TB model won't change ETC TQ requests in my experience.

    This car is using a twin 60mm TB, which I have created a very accurate model for; verified on maybe 10 different cars (pre 2015). The ETC setup is the same on the newer cars, just with larger dimension tables (I wish we could back-port that).

    If you look at the roll-on log I posted, you will see that at 75% pedal, there is like 0.3* of ETC angle error, no ETC TQ error; but already at this point ETC TQ request has diverged a lot from the DD table. Or, here at this point, since it matches so closely to a DD cell:

    ETC-TQ-clipped.jpg

    In all my pre-2015 experience, ETC TQ requests always fall on the DD table, based on only RPM and pedal position. Something else is at play in the newer PCM.