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Thread: TR Intervention & Not Following Commanded Line Pressure

  1. #1

    TR Intervention & Not Following Commanded Line Pressure

    Good Morning!

    I am having a few issues with my twin turbo 2021 10r80 Mustang and looking for some guidance.

    I am attaching a log that will show a pull on both 8ish lbs of boost and 14-15psi, on the dyno this car pulled clean with no issues and made right at 1,000 rwhp, however upon taking the car out on the street and running it through the gears, I immediately noticed that TR is heavily intervening and dropping the spark with every shift which will last through the entire gear, Spark source will go from borderline to torque control. In looking at the log, it looks pretty clear that my ETC torque request is much lower than actual torque which I can only assume is the culprit?

    The second concerning issue is the lack of line pressure I am seeing, its only requesting 247ish psi through most of the pull and only sees 300+ at the end of 6th gear, I can also only assume this is not near enough pressure for a 1,000 rwhp car.

    Please let me know your thoughts and I am certainly open to any and all feedback, thanks in advance!

  2. #2
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    Very interesting log. I'm not sure I can help you but some other observations are:

    - Your GDI blend is dropping very low. I believe it's due to EOI clip, which can be lowered. Your GDI pressure is good, indicating the HPFP is keeping up, even at 3000 psi. You should log GDI pump duty cycle to see how close it is to the limit. I believe you can run the EOI back to about 120 deg, while yours isn't going past 150. This allows the GDI system to do more.
    - No point in logging DI End of Injection Angle (Compression), as that is only active during cold start AFAIK.
    - Your torque request and brake torque are way below what your tables suggest. Any idea why that is?
    - The torque source remains Driver Demand, which indicates it's not hitting any other limits. Your suspicion seems correct based on that. I just don't know why your torques are so low compared to the torque management tables.

  3. #3
    Quote Originally Posted by engineermike View Post
    Very interesting log. I'm not sure I can help you but some other observations are:

    - Your GDI blend is dropping very low. I believe it's due to EOI clip, which can be lowered. Your GDI pressure is good, indicating the HPFP is keeping up, even at 3000 psi. You should log GDI pump duty cycle to see how close it is to the limit. I believe you can run the EOI back to about 120 deg, while yours isn't going past 150. This allows the GDI system to do more.
    - No point in logging DI End of Injection Angle (Compression), as that is only active during cold start AFAIK.
    - Your torque request and brake torque are way below what your tables suggest. Any idea why that is?
    - The torque source remains Driver Demand, which indicates it's not hitting any other limits. Your suspicion seems correct based on that. I just don't know why your torques are so low compared to the torque management tables.
    Thank you very much for your reply!

    Noted on the DI side and will include that in my next log, I did want to use more PI in the upper load areas to keep the DI side happy.

    I am at a total loss of ideas why my ETC request is very low, on the dyno and through a clean pull on 15-16 PSI, reported torque seems to be right on line with where I feel it should be (900ish)

    I Have been tuning GM's most of my life, so trying to understand the Ford logic is interesting. I guess I am really trying to understand where ETC torque request comes from, and how the trans line pressures are commanded. I just don't want to smoke the trans out of this thing from commanding to low of a line pressure.

  4. #4
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    What power did it make on the dyno?

  5. #5
    Quote Originally Posted by engineermike View Post
    What power did it make on the dyno?
    on pump gas and 8 psi it made 750ish, on x85 and 16 psi, right at 1,000 rwhp

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    Nice!

    I have a power and torque calculator built into my VCM scanner. On the low boost pull, it indicates 705 hp and 550 ftlb, with the torque lining up very close to your "Engine Brake Torque" PID. On high boost, it indicates right at 900 hp and 700 ftlb, again agreeing well with the Engine Brake Torque PID.

    The ETC Torque Request should be around 750 ftlb based on your tune. Apparently this problem has been discussed at least twice before on this board, but I didn't see any clean solutions. Now I'm intrigued....

    As for the transmission pressure, 247 psi = 1700 kpa. If you look under Transmission->Shift Pressure->General you can see several of the tables are set to 1700 kpa. Some change this to 2100. I don't know enough about how it works to recommend it, but if the shifts are good and you aren't getting slippage, it might be ok as is. One thing I did do is apply shift character 2 and cut the upshift torque down to 530 ftlb (500 in Normal) in an attempt to extend transmission life.

  7. #7
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    On another note, your EOI clip is set to 100. i have mine at 75 now, but I think if I were you I'd try 90, maybe 85, and see if the stock pump still keeps up. If it doesn't, you can lower your GDI pressure and it will increase the pump capacity.

  8. #8
    Quote Originally Posted by engineermike View Post
    Nice!

    I have a power and torque calculator built into my VCM scanner. On the low boost pull, it indicates 705 hp and 550 ftlb, with the torque lining up very close to your "Engine Brake Torque" PID. On high boost, it indicates right at 900 hp and 700 ftlb, again agreeing well with the Engine Brake Torque PID.

    The ETC Torque Request should be around 750 ftlb based on your tune. Apparently this problem has been discussed at least twice before on this board, but I didn't see any clean solutions. Now I'm intrigued....

    As for the transmission pressure, 247 psi = 1700 kpa. If you look under Transmission->Shift Pressure->General you can see several of the tables are set to 1700 kpa. Some change this to 2100. I don't know enough about how it works to recommend it, but if the shifts are good and you aren't getting slippage, it might be ok as is. One thing I did do is apply shift character 2 and cut the upshift torque down to 530 ftlb (500 in Normal) in an attempt to extend transmission life.
    Great catch! I am assuming you are referring to the power on up high gain shift tables? If so that may in fact be the culprit. I agree as well that my requested torque should be in line with what im requesting in the file. I feel there is still something being overlooked in the file that may be isolated to the 21's?
    Last edited by 1badss; 10-21-2021 at 12:32 PM.

  9. #9
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    I don't know if it's a 21 issue, but this one is doing the same identical thing:

    https://forum.hptuners.com/showthrea...-pcm-pull-this

  10. #10
    interestingly enough, Justin is a friend of mine and we have discussed this. I have made all the appropriate revisions to my torque/inverse tables, while also increasing DD and no matter what I do, I cant get the torque request up anymore.

    What's also interesting is his did not appear to gut the spark out like mine does on shifts.

  11. #11
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    I've been struggling with a similar issue, but only on the initial hit. That said, I have all possible limiters (torque related and otherwise) off. What I do see is my ETC Torque Request vs. Brake Torque are pretty far apart but they fall in line right after the 1/2 shift. I've tweaked my torque model and Driver Demand individually and together to no avail. It doesn't seem to effect the run as everything is where it should be. Fuel, Spark and Throttle are exactly where they should be.

    Screenshot 2021-10-21 125325.png

  12. #12
    mine will not come inline if i hold this thing to the floor through 6 gears, it will just keep gutting the spark every shift, but on the initial gear that i start the pull, I have commanded spark, once it shifts, it all goes downhill.

  13. #13
    Tuner barkingspud's Avatar
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    Quote Originally Posted by 1badss View Post
    mine will not come inline if i hold this thing to the floor through 6 gears, it will just keep gutting the spark every shift, but on the initial gear that i start the pull, I have commanded spark, once it shifts, it all goes downhill.
    I saw that. I see you have a lot of the nannies still on such as 44775 (Fuel Cut), 33458 (Spark Only TQ Ratio) and others that are Engine related. Trans related,Torque Modulation/Positive Torque Mod and others. The Spark Source on the shifts is pointing to Trans Shift Mod (Modulation) which is where the spark cut is coming from. You can disable 22821 and 1463 and this should help. From there it's a slippery slope turning stuff off or disabling them. All depends on what type of appetite you (or your customer) has for risk of Trans and/or Engine failure.

  14. #14
    this is my personal car, so I am able to be a bit more aggressive than if this were a customer car. The trans is built, turning off torque modulation in turn turns off any torque management during shifts, am I correct?

    I thought about disabling 33458 and not allowing any spark intervention, but wasn't sure if this was the "proper" way or just a quick workaround to my problem.

  15. #15
    Tuner barkingspud's Avatar
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    Quote Originally Posted by 1badss View Post
    this is my personal car, so I am able to be a bit more aggressive than if this were a customer car. The trans is built, turning off torque modulation in turn turns off any torque management during shifts, am I correct?
    Correct to a point. TQ Management is pretty aggressive on these cars. As I mentioned, there are a ton of other things that can be turned off. It's all up to what level of risk you're willing to take. This will get you started.

    Quote Originally Posted by 1badss View Post
    I thought about disabling 33458 and not allowing any spark intervention, but wasn't sure if this was the "proper" way or just a quick workaround to my problem.
    Start with the above and go from there.
    Last edited by barkingspud; 10-21-2021 at 01:38 PM.

  16. #16
    would I be correct in my assumption to setting 33458 to all 1's and this will eliminate spark intervention? Or should I still allow some to intervene?

  17. #17
    Tuner barkingspud's Avatar
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    Quote Originally Posted by 1badss View Post
    would I be correct in my assumption to setting 33458 to all 1's and this will eliminate spark intervention? Or should I still allow some to intervene?
    Actually, it's opposite and I'm not sure why they haven't fixed the descriptions yet. This is how I have mine set.
    33458.png

  18. #18
    Quote Originally Posted by barkingspud View Post
    Actually, it's opposite and I'm not sure why they haven't fixed the descriptions yet. This is how I have mine set.
    33458.png
    other than traction control and torque steer, ours look very similar?

  19. #19
    Tuner barkingspud's Avatar
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    Quote Originally Posted by 1badss View Post
    other than traction control and torque steer, ours look very similar?
    Yes. I have just about everything else off too. Not typically recommended but it gets the job done. I don't beat on my car on the street. Only at the Drag Strip so, it works out. Just for reference, here is one of my logs.
    Attached Files Attached Files

  20. #20
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    To be blunt, I think y’all are heading down the wrong path.

    The torque source is driver demand. While the shift is taking place, it changes to shift modulation then back to driver demand. Once it switches back to driver demand, it’s no longer modulating torque for the shift, but for some other reason spark stays in torque control. It would follow that it’s trying to achieve the lower ETC torque request since the wot start and end force the throttle blade open. There are also time limits for shift modulation, whereas this on lingers longer than that.

    Table 44775 spark torque ratio is the first resort when cutting torque. 0.0 allows most control (within limits) and 1.0 is no control. Here’s the problem….if it doesn’t get what it wants with spark, it moves to enleanment. Your table 44775 is already set up to bypass enleanment and move to fuel cut, which is better. If you disable spark torque, it will just move on to fuel cut. The best way to manage this is to figure out why it’s reducing torque and address the cause.

    That said, under transmission torque management, you can raise or lower the torque allowed during the shifts. If you max out these values, it won’t cut torque for the shift…at the expense of transmission hard parts.