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Thread: command open loop boost control fg

  1. #1
    Potential Tuner
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    Sep 2017
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    command open loop boost control fg

    hey fellas

    starting out in the falcon tuning side of things (been doing gm up intill now) and i cant seem to find where to force the car into openloop boost control to setup the wastegate duty pressure.

    i found a setting called "turbo logic, enable/disable" is that it?

    i also got told theres a vct angle to boost error table that should be disabled when doing openloop boost control but i wasnt able to find that table in the tune?

    operating system is = HAEDLL8

    cheers

  2. #2
    Tuner in Training
    Join Date
    Dec 2018
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    21
    Leave turbo logic enabled.

    The areas I would be looking under are "Airflow" - "Pressure Control" and also "Turbochargerl"
    "Torque Management" - "SC/TC Boost Control"

    Download a couple of modified strategies from the repository and do a compare with an unmodified tune. Hopefully someone more knowledgeable can chime in soon and add to and or correct the above, I'm a beginner here too sorry.

  3. #3
    Tuner in Training
    Join Date
    Dec 2018
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    21
    ok so when I first started here I went through most of the posts and copied what seemed relevant into a text document. I hope this helps.

    SOURCE = https://forum.hptuners.com/showthrea...60-Tuning-n00b

    Boost control:

    Most tuners seem to run open loop boost control, however when street tuning its easy to dial in your boost in closed loop using the 'desired boost' table (its in inches of mercury and a rough duty cycle estimate and then log wastegate duty cycle, boost error, desired boost etc in a number of gears and then work out what dutycycle it likes for what rpm and the 'desired' boost level you have commanded. This gives good data on approximate wastegate duty cycle if you switch to open loop. The only thing to look out for is if you go straight open loop (i.e. you're only running off the duty cycle table) is that you may need to command a little less duty cycle at 2500rpm compared to what the pcm calculates in closed loop.....which is normally 100%.


    OPEN LOOP: you need to zero the proportional gain multiplier table, zero all integral and proportional gains (on/off boost ect) and wastegate period. The wastegate boost FMEM (failure management effects mode) is set at a 50% reduction from factory so that needs to be set to zero reduction. All torque 12, 23 and 34 shift underboost need to be zero'd. P1227 limit (overboost) needs to be set to it's maximum. The over and underboost for open loop DC and the over and underboost for open loop DC error need to be maxed out

    CLOSED LOOP: the system references a value from the wastegate duty cycle table, measures the boost, determines an error against the "desired boost table" and then uses the PI system to correct the duty cycle to reach the target level. The factory PI system is reasonably good so just leave is standard for now. In factory form the throttle body is a fair way from the turbo and too far to use aggresssive proportional gains so just work on the basics to start with. With closed loop all you really need to do is zero out the torque 12, 23 and 34 shift underboost, raise the 'P1227 limit' a little, make the overboost for 'open loop DC error' more negative and raise the 'underboost for open loope dc error'. The latter two won't need much at low boost...say 0.5 adjustment. From here you can set the desired boost table which is in inches of mercury. The PCM will always try and target these values and will adjust the duty cycle to get there. Ignore the manifold charge temps (MCT i.e. y-axis) and set all verticle values to the same desired boost level. Now you have to dial in your wastegate duty cycle that will achieve your 'desired boost'. These are the values that the pcm will use to start controlling boost so it is important to get them right (again ignore MCT and all verticle values can be the same). You will need to datalog the pcm's adjusted 'wastegate duty cycle' value and compare it to your commanded duty cycle. Refine this so it's adding a small amount of dutycycle in low gears and removing a little duty cycle in high gears.

  4. #4
    Potential Tuner
    Join Date
    Sep 2017
    Posts
    2
    thanks cracka, appreciate the information passed on

    good to know theres a way to set up good boost control in both open and closed loop, also sounds to me like closed loop is easier to setup with the help of a few datalogs...?

    in regards to adjusting the torque shift under boost, theres 2 areas to adjust the 1-2 2-3 3-4 torque reductions. one is under torque management/general and theres another one under torque management/upshift
    would i zero them out in both tabs?

    cheers
    Last edited by yukbumer; 01-25-2019 at 06:13 AM.