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Thread: atmospheric pressure

  1. #1

    atmospheric pressure

    How much difference in tuning would there be at these levels= 12.9psi/3500ft. when seal level is 14.7psi?
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    Last edited by carotene; 2 Days Ago at 11:10 PM.

  2. #2
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    What's up with your engine coolant sensor? The log says it's stuck at -40?C, is the sensor connected?
    I assume it has an automatic transmission. And can you pinpoint at what point in the log the backfire happens?

    The default turbo on these engines has no vanes, and it's wastegate controlled. So you can't destroy them.


    Quote Originally Posted by carotene View Post
    How much difference in tuning would there be at these levels= 12.9psi/3500ft. when seal level is 14.7psi?
    No real difference in tuning, only lower final power output because of the limitation of the turbo. The exhaust manifold is quite small and it can't flow well at higher RPM, therefore it can not compensate for the lack of atmospheric pressure. At the sea level it can flow about 135-140 g/s air at high load.
    Last edited by sbarisic; 1 Week Ago at 11:30 PM.

  3. #3
    Senior Tuner cobaltssoverbooster's Avatar
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    not having a coolant reading is a big issue. Coolant temp reading negative values kicks in a heavy fuel multiplier as the ecu thinks the motor isn't warm enough to 1) properly seal and 2) correctly flash the fuel into a vapor when injected.
    If you cant pull out into traffic because of power loss, its not becuase of the baro is 12.9 instead of 14.7, its becuase your likely having sensor and wiring issues that are causing extreme fueling control.

    A stock motor shrouded vs. unshrouded is a negligble concern. Revisit all of your sensors and make sure they are reporting reasonable values. Any that aren't, go fix them before you continue forward.
    2000 Ford Mustang - Top Sportsman

  4. #4
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    Okay, let's start from scratch.

    Do you have a wideband?
    What are the mods on the engine? As in, the injectors, the turbo, did you relocate the MAF sensor, what about the MAF sensor housing diameter, what does the airbox look like, the cat converter also removed, what about the camshafts and so on..


    You added 5 lb/h to the injector flow rate across the whole table, unless you changed the injectors, i wouldn't do that.
    The ECU thinks the injectors flow more than they actually do therefore leaning out the mixture everywhere.
    Lean mixture usually means hard pops and bangs.


    Looking at the log, the power enrichment does not kick in correctly. You seem to be holding the throttle at 50% and building boost up to 1 bar, and because PE does not kick in (set at 70%), you run at the 14.7 ratio. Together with the, i assume, badly set up injector flow rate and disabled O2, you run even leaner, making it bang.


    Also, did you reeeeeeeally disable every DTC code? Why?
    Please disable them just as-needed, they're a very useful diagnostics and tuning tool.



    2019 off road buggy vats tcs TESTFIX1.hpt

    Please try this.
    I tried to undo most of the things i think that aren't really required, including some of the DTCs.
    The knock airmass, torque tables, driver demand tables, airflow turbocharger max pressure ratio and surge line - this should max out the stock turbocharger.

    Are you still running the MAF sensor? By default the VVE table is waaaay off and i do not recommend running on MAP only.
    The ECU is designed, as far as i know, to take both the VVE and MAF sensor and blend them into dynamic airflow value.
    And based on said dynamic airflow value it handles fueling. Except for part throttle where it may use one or the other based on some magic in the background.


    EDIT:

    Oh, and what about the fuel system. Do you still have the FPCM or is it a return style system with a MAP referenced pressure regulator.

    EDIT:

    Going across all your tune files posted across the forum, it's pretty hard to keep track of the changes.
    Last edited by sbarisic; 3 Days Ago at 02:52 AM.

  5. #5
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    Did you actually confirm it is running said AFR numbers with a wideband?
    You say you are running the bosch 42lb injectors, if you are, your flow rate is not correct


    Here are the stock flow numbers

    stock.png

    And here are your current flow numbers

    current.png


    This is, according to this forum, what it should look like

    should.png
    Last edited by sbarisic; 2 Days Ago at 08:02 PM.

  6. #6
    Senior Tuner cobaltssoverbooster's Avatar
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    i dont have time to dive deep in tune reviews these days. If what hes has said is true then i would bee looking into what he has to say.

    If your mostly stock then the factory maf and vve tables should run regardless of installed upgrades like intake, injectors etc. The deal is, if you have shit going into the computer then you have shit coming out of the computer. What this statement means is that if your inputs aren't working and your calibrations for those inputs are not correct, then what you get out of it is not going to be correct or even close for that matter.
    When you said sensor readings weren't working, I took that as a sign that you have input and/or calibration issues. My next questions would be:
    Where did you get your injector data?
    What is the part number for your installed injectors? With this the forum members can verify flow rate data.
    What type of fuel system do you have? (Tell us if you have a fuel system with a 1:1 vacuum referenced return type regulator or the stock style FPCM system)
    What wideband do you have?
    Where is your wideband installed?
    Is your wideband in a weld in bung or is a hose clamp pad?
    How did you wire your wideband to feed data to MPVI?
    What are your calibration settings for your wideband input in VCM Scanner?
    and the biggest question...what are all of the the changes to the motor? Identify all the performance parts that are installed.

    Keep in mind that we aren't seeign your car in person and we don't know anythign about it. Looking at a picture or listening to an audio clip doesn't even come close to being there and experiencing the "issues". To get the best help we rely on you to supply all of the pertinent information.
    I highly suggest answering all the questions you haven't answered from sbarisic. Whatever you can provide will only help you here.
    2000 Ford Mustang - Top Sportsman