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Thread: Pulling Timing under Boost

  1. #1
    Senior Tuner Higgs Boson's Avatar
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    Pulling Timing under Boost

    I am tuning a 416 with an ECS 1500 and any time I get into boost (over about 110 kpa) it rips all my timing down to -.5 to 1 degree, it releases it back to commanded 12 degrees for a moment, then pulls it all back out again.

    It shows up under Knock Retard, which freaked me out at first, but it's not real knock as best I can tell....any idea of which table I missed? I know, post the tune, I am just away from the tune for a while.

    Max Torque Timing? stock at the moment
    Airmass? increased, thinking of putting it back to stock
    Peak Torque? has been increased
    Driver Demand? throttle doesn't close, has been raised also

    It is also Flex Fuel, running 11% alcohol (pump 93) and no meth....heck, maybe it is real knock. I will pull the plugs when I get back and it's cooled off.

  2. #2
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    I would consider your injector timing or you may just be too rich.
    Jaime

  3. #3
    Senior Tuner Higgs Boson's Avatar
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    injector timing is 370, it started out super rich but it's dialed in right at 12:1 now.....still too rich, you think?

  4. #4
    Senior Tuner Higgs Boson's Avatar
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    here is a scan:spark issue.hpl

    i am expecting this to make around 700 on 93 and as much as my fuel pump will allow on E85...850?

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    Quote Originally Posted by Higgs Boson View Post
    injector timing is 370, it started out super rich but it's dialed in right at 12:1 now.....still too rich, you think?
    I don't have any personal experience on the FI LT1s, but many are saying closer to 12.5 range and the Cobalts I know are similar. There is an A&A thread about it somewhere.

  6. #6
    Senior Tuner Higgs Boson's Avatar
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    i am going to give it a shot at 12.4

  7. #7
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    bring up the max torque timing a bit in that area and see what it does. You may be running into the virtual wall between the two in the sense of urgency.
    The most hated, make the most power.
    93 Ranger. 5.3 D1X. 1069hp.

  8. #8
    Senior Tuner Higgs Boson's Avatar
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    it is still pulling timing but its smoothing out and getting better as i lean it out. still working on it. after I nail down the afr i will play with max torque timing and spark.

  9. #9
    Senior Tuner Higgs Boson's Avatar
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    decided to put in some E85, came out to a 55% mix and the low pressure pump ran out of capacity at 3500 RPM. Joe at CPR has a supplemental pump kit I ordered tonight so hopefully I will have it in a week and can resume.

  10. #10
    Senior Tuner Ben Charles's Avatar
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    Higgs, what other mods for the fuel system? I assume a Cam/lash cap? How much boost? Your running out of fuel from the In-tank fuel bump?

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  11. #11
    Senior Tuner Higgs Boson's Avatar
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    Quote Originally Posted by Ben Charles View Post
    Higgs, what other mods for the fuel system? I assume a Cam/lash cap? How much boost? Your running out of fuel from the In-tank fuel bump?
    lash cap
    Z06 HPFP and Z06 injectors
    commanding 20MPa
    no cam lobe
    416ci @ 12:1
    was running about 16 degrees of timing (E55)
    boost was about 5 psi when it ran out, should be about 10psi at 6500

    in tank pump pressure started going down around 3500 and the high pressure pump followed by about 3800

    the price of ethanol.....i just don't want to use meth. hopefully the pump kit will allow me to run full on E85 when all is said and done. guess I will see in like 2 weeks. for now it's going to have to be just golf....or race gas, hmmm.....

    Engine.jpg
    Last edited by Higgs Boson; 09-09-2015 at 10:08 PM.

  12. #12
    Senior Tuner Ben Charles's Avatar
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    Hmmm how much power you think its making?? What pulleys you running?
    I would assume that setup shouldn't have any problems making 700rwhp on E55

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  13. #13
    Senior Tuner Higgs Boson's Avatar
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    My goal is 800+ so maybe I will be disappointed......I can always put on a smaller pulley, it has a 3.75 now and is a 10 Rib.

    I can say it pulls as hard or harder than my C5Z with 725/725 (nitrous). Of course, it is hard to tell right now. One thing to note is one of my saved logs shows 68 lb/min at 5800 RPM on 93....so that is promising that I will be over 700 on 93 and hopefully 800 on E85.
    Last edited by Higgs Boson; 09-09-2015 at 11:28 PM.

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  15. #15
    Senior Tuner Higgs Boson's Avatar
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    2014. btw, andy, i am going to email you my truck file, bill couldn't match it up with your ticket.

  16. #16
    Senior Tuner Higgs Boson's Avatar
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    For the guys that have tuned high HP supercharged C7s, how high are you going with start of injection?

  17. #17
    Senior Tuner Higgs Boson's Avatar
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    Out of Fuel.hpl

    Please review this log when you have a minute. I cannot figure out why it is showing Retard.

    Also, it looks like my low pressure pump is going out around 3500 RPM and the HPFP loses pressure as well as a result (??). So the injectors work overtime to try and keep up.

    Is this what you are seeing?

  18. #18
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    Quote Originally Posted by Higgs Boson View Post
    lash cap
    Z06 HPFP and Z06 injectors
    commanding 20MPa
    no cam lobe
    416ci @ 12:1
    was running about 16 degrees of timing (E55)
    boost was about 5 psi when it ran out, should be about 10psi at 6500

    in tank pump pressure started going down around 3500 and the high pressure pump followed by about 3800

    the price of ethanol.....i just don't want to use meth. hopefully the pump kit will allow me to run full on E85 when all is said and done. guess I will see in like 2 weeks. for now it's going to have to be just golf....or race gas, hmmm.....

    Engine.jpg
    do you have a way to log actual pressure like the LNF does? commanded is one thing, actual is another.
    The most hated, make the most power.
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  19. #19
    Senior Tuner Higgs Boson's Avatar
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    Quote Originally Posted by Area47 View Post
    do you have a way to log actual pressure like the LNF does? commanded is one thing, actual is another.
    look at the log in Post 17, it is actual.

    Right at or right before 3500 RPMs
    Low Side goes from 60 to in the 40s
    HPFP goes from 19.8 to 6 MPa.
    Injector Duty Cycle goes straight into the mid 40%

    shooting for 12.45 AFR (.85 Lambda)

    Spark is 8-12 depending on what I am commanding, and it starts to pull down to 0 (always shows Knock Retard of 10) I guess as it senses pressure start to go away.

  20. #20
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    i can't look at the log at work. sounds like a fail safe in the background running to try and protect itself from failure. If the timing follows suite with the fuel pressure.
    The most hated, make the most power.
    93 Ranger. 5.3 D1X. 1069hp.