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Thread: GT350 VCT Disabling issue

  1. #1
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    GT350 VCT Disabling issue

    2018 GT350 bone stock form

    *VCT Disabling during WOT entering VCT Schedule mode=Disabled*

    WOT in all gears above 5krpm vct will leave optimum power mode & enter disabled but will also go back to optimal power mode then back to disabled

    No engine codes
    5w50 oil motorcraft & have tried amsoil just to change it up
    oil pressure is good

    here is attached log

    any help or input would be greatly appreciatedvader gt350 stock log VCT disabling 1.hplgt350 log 1 completely stock.hpl2018 gt350 read.hpt
    Last edited by Vaderperformance; 12-08-2020 at 10:36 PM.

  2. #2
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    Torque limits, Your MAP is calculating out on the higher side. It can cut fuel, spark, throttle, VCT... All kinds of things depending on how your limiter configuration is set.

    TQ limits.jpg

  3. #3
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    can i send you both my stock & tuned file? thanks for help

  4. #4
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    I’m not sure what the goal is, but I was able to lock vct by commanding a single mapped point in the index arrays and command the equivalent cam timing in optimum power. As a result, my cams stay the same all the time. I did this so I could accurately calibrate the borderline knock tables one at a time rather than guessing at which one to correct.

  5. #5
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    goal is to get my vct to be in schedule mode-optimum power & not disable during WOT

    *keep in mind this is a stock log*

  6. #6
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    Can you post you cal?

  7. #7
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    whats your email ill send stock file

  8. #8
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    On second thought I might not be able to help tremendously beyond this....I noticed that at the same time that it switches to vct disabled, it also switches to base timing (aside from polling time offset). This may be an affect rather than a cause though.

  9. #9
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    still no luck finding issue..

  10. #10
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    I thought i have seen an option parameter in the tune to lock your cams at a certain angle?

  11. #11
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    Is your car truly bone stock? On the stock tune you should have no issues, and only need to change very little for basic modifications.

    You can try changing min and max BARO learning to above 107.5KPA, just to see if it hasn't properly learned the high BARO and keeps your throttle body model from going into speed density "MAP max delta above BARO". Remove some less useful channels and add BARO to see what the ECU is thinking the BARO is. Seeing 105-107 MAP is very high, especially considering the highest BARO ever recorded was 108.3KPA and some pressure drop into the manifold is to be expected. If you can keep it happy to be on the throttle body model you won't have to treat it like a boosted car. A lot of VCT mode scheduling depends on the learned barometric pressure. Then of course there's torque limits that you can easily run into when the torque model is based around STD(101.3KPA) and you are 5-7KPA(equivalent to a pound of boost) higher than that.

  12. #12
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    I am curious to see what has happening in Vaderperformashelby tune. I have not see this issue with stock gt350. last one I tuned put down 480rwhp, mods was JLT CAI 90mm Throttle body and spacer plate.

  13. #13
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    car is truly bone stock!

  14. #14
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    are you willing to post your tune? what is theHR3A-1204C-???

  15. #15
    Murfie has given you incredibly sound info, where is your calibration? can you not post it?

  16. #16
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    2018 gt350 read.hpt


    here is the file that is in the car now (Stock file)

  17. #17
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    I do not see anything out of the ordinary, compared to my tune files other than torque and spark table. try changing the settings for torque.

    torque 1 800
    torque 2 800
    Max wheel torque error 50000 from 26095

  18. #18
    I’ll check it with my 2016 stock file tonight.

  19. #19
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    i have still not been able to fix this issue.. any help is greatly appreciated

  20. #20
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    Quote Originally Posted by Vaderperformance View Post
    i have still not been able to fix this issue.. any help is greatly appreciated
    Check ETC model, log the throttle as well as injector fuel commands, maybe try reduce (or eliminate) the cam retard in the VCT tables.