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Thread: Help a beginner out (4.3 in 2000 Blazer)

  1. #1
    Potential Tuner
    Join Date
    May 2019
    Posts
    1

    Help a beginner out (4.3 in 2000 Blazer)

    Background info:

    I'm a complete beginner to tuning. My first tuning project is my 2000 Chevy blazer 4x4 with a 4.3. its an offroad/ mudbogging toy so high speed isn't what I'm going for, but it will see WOT often and i want to get as much power and torque out of it as i can.

    Engine info:

    4.3
    -marine intake/injectors
    -gasket-match ported heads and intake
    -Comp Cams 266hr cam
    -Ls6 beehive valve springs
    -headers,cat delete, glasspack. factory y pipe.
    -Single nozzle NX proton nitrous kit

    Trans:

    4l60e with corvette servo


    I played with the trans, and got that pretty set i think.

    I'm wondering where to start with tuning my engine. So far i set my injector flow rate to 28.9 LB/HR to match the marine injectors flow/ pressure and increased my rev limiter by 200rpm. i just don't know where to go from here. Any insight would be appreciated!

  2. #2
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
    Location
    Rogers, MN
    Posts
    13,533
    Get a wideband o2 sensor so you can properly fix the airflow model.

    Getting the fueling under control is 100% a must do thing. Everything from part throttle to idle and of course full throttle. You wouldn't want to be flooring it and have it go lean on you because the fueling wasn't there.

    Off hand I don't remember what computer that runs but calibrating the MAF curve and VE table is where you need to start. Read up on using the wideband o2 sensor to create a custom error graph that shows the error between the commanded AFR and the actual AFR the wideband is seeing.

    Anything else can be done once fueling is in line, like optimizing timing for power and playing with leaner or riching fuel mixtures at wide open throttle. It's a good idea to start safe around a 12.0 AFR when you get into WOT tuning.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  3. #3
    Potential Tuner
    Join Date
    Jul 2018
    Posts
    6
    sweet set up! i have similar 4.3 v6silverad 70mm turbo, marine intake 32lbs , glad to see guys out there using it still! start with safe AFR , try speed dense , i ditched my mass air flow sense,good for turbo set up ?not sure about NOS, baby steps