Results 1 to 2 of 2

Thread: MAP adjustment

  1. #1
    Tuner
    Join Date
    Aug 2019
    Location
    Greenville, MI
    Posts
    58

    MAP adjustment

    I'm not an advanced tuner... Just looking to trim off some of the LTFT. Its consistent at -12.5. Drove for almost an hour logging data. I was told to knock 3% off the MAP table to hopefully get the trim up to -5 or so. I'm not at a wideband point yet as this motor is completely stock and just looking to trim it up for normal driving.

    Take a peak if you feel and send some info if you'd like. I tried looking at how-to's and what not but not all this makes sense really....

    20 rich_lean O2 changed 481 to 375 mv.hpt
    19-11-13 11-33-27.hpl
    19-11-13 12-14-17.hpl
    fuel watch.Channels.xml
    MPG.MathParameter.xml
    horsepower.MathParameter.xml

    I tried a MPG math formula and I must have done it wrong.... go figure.

  2. #2
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
    Location
    Rogers, MN
    Posts
    13,533
    If the calibration was setup purely to run speed density, then you would only adjust the VE table to remove fuel. In this case you are running a MAF, so you have to account for both the MAF curve and the VE table.

    I do not suggest removing fuel from the entire VE or the entire MAF curve, just remove the fuel from where the engine is at while cruising. So that is likely under 3,000rpm and under 7,000hz on the MAF curve. You can remove the small amount of fuel, smooth each table and flash the file in. Reset the fuel trims and go for another drive.
    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.