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Thread: Scaling Tune after New Injectors ... some Q's

  1. #1
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    Default Scaling Tune after New Injectors ... some Q's

    Hi Guys, been a while! Turbo Silverado Sold and CTS-V Wagon in the Garage now.

    Dabbled with helping tune a bit a few years ago with my Truck, but please consider me a beginner who's eager to learn with the new ride.

    I just installed a 2.45" pulley and FIC1200 injectors along with a FlexFuel Sensor kit.

    I copied all the tables from the excel spreadsheet from their website (https://fuelinjectorclinic.com/GM-DATA/EFI-LIVE-1200) and when it got to the Base Fueling table (B4001), the max flow was limited to ~126lb/hr.
    After some research here, I scaled the table by 65% to get the max possible range in the table (got a max of ~120), and the IAT multiplier (B1213) by the same ... assuming IAT modifier will work on this ECM instead of going to the stoich table? Any other tables need to be scaled?

    It's still lean (o2 showing ~50-100mV) at first start so guessing its due to the extra airflow from pulley swap, and still being in open loop?
    My plan was to keep bumping up the entire IAT multiplier table until I get a decent idle before it goes into open loop. Acceptable?

    Along with that my other question is with the tables I modified using the FIC spreadsheet ... do I need to scale any of those?
    -Injector offset table (B1211)
    -Short pulse adder (B1203)
    -Min Inj Pulse Width (B1204)

    What do I do with the injector information and flow sheet they sent with this set of injectors? Does that information get plugged in somewhere to equalize flow between cylinders? I did keep track of where each injector went during install. Can I use the Slope Flow matching data to modify B1520 (divide 1200 / ** to get the mutiplier)

    Thank you!
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  2. #2
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    Just an update, I played around with offsetting the IAT multiplier table and got a nice idle with no LTFTs, drove around the block and it felt good ... will get tuned and gone over in a week or two

    Sent from my SM-G965U1 using Tapatalk

  3. #3
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    the iat multiplier table will not go beyond the max limit of 127lb/hr. So this may not work. Be careful or everything will be off.
    "All that is needed for the triumph of evil is that good men do nothing..."

  4. #4
    Joe (Moderator) joecar's Avatar
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    Post your latest tune and some logs of it.

  5. #5
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    Hey guys, I just haven't had time to do much with the amount of rain and general crappy weather we've been having. Here's what I have for now. I returned the IAT multiplier back to stock, and instead adjusted B3671 Stoich AFR until I got it to run somewhat decent. I thought I had LTFT off at one point, but the most recent log seems to have it active. Now my issue seems to be PE mode where is goes RICH and then detects knock.
    Is there a way to get my fuel economy gauge to be accurate on the cluster again? HPT seems to have a table to scale that? One reply about scaling tune from a shop who use HPT was;

    "Half IFR, double Stoich, Half Density for cluster calcs, half AFR term use the rest of the data supplied by inj. manufacturer"

    Thanks in advance!

    -Tuan

    ps: also included my stock tune jic you wanna see where I started from.
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    Last edited by Mean Green Z28; May 24th, 2022 at 12:23 PM.

  6. #6
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    IAT Multiplier is not the way to go... double the stoich is the easiest method.
    "All that is needed for the triumph of evil is that good men do nothing..."

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