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Thread: Individual Fuel Trim

  1. #1
    Join Date
    Mar 2016
    Location
    MN
    Posts
    19

    Default Individual Fuel Trim

    Good Morning. I have a 540 with Twin 94mm turbos. I'm running 16 injectors with one set as the lead at idle until 2000 RPM and then they split duty of 50% each. 160 lb/hr injectors. I have ten WB2 sensors and 8 EGTs and I'm datalogging all of it. I'm running E98 fuel with a sheet metal intake. The intake is feed from the rear of the engine from a intercooler. Injectors all flow tested and matched set ups. New engine and all the valve train has been checked for accurate valve adjustment. Compression all good across the board. I have cylinders #1-#2 & #6 running lean. I have added about 20% to all of them and have noticed them getting better but they're still off a whole point. I'm targeting 11.3 on the fuel scale. Any suggestions and help would be greatly appreciated. I'm playing very safe on timing, so do I start to add timing to cylinders? 1 + 2 I think is happening because they're at the end of the intake and the air is getting slammed into those cylinders, but I still need them to be correct. Thank is advance.

  2. #2

    Default

    I'd start to target a little richer AFR. The 20% you're adding to cylinders #1, #2 & #6 is adding to the total Fuel Flow, which in turn will trim the fuel to the remaining cylinders. 20% is a lot to add. Who made the intake? You could also try reducing timing to those cylinders as well.

  3. #3
    Join Date
    Mar 2016
    Location
    MN
    Posts
    19

    Default

    Good Morning. Here's what I found out so far. I have at least two bad WBO2 sensors. I switched them with others and then ran. The lean moved to those cylinders. When I talked about adding 20%, that was to each of the 3 lean cylinders, so that would only add fuel to them. Since I'm new to a boosted application, but know NOS very well, I also learned that my safe timing is also skewing my lean condition. More timing = running richer. Strap reading on the spark plug is still important. Timing at the bend is a good starting point. I'll keep you udated after the 4th races.

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