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Thread: What is concidered at good tune fuel trim wise?

  1. #1

    What is concidered at good tune fuel trim wise?

    So I'm in the middle of tuning my 2010 Camaro SS single turbo with supporting mods.
    when tuning MAF and STFT only where should my fuel trims be to (meaning for example + or - 5%)?
    what is considered a good tune for part throttle?

  2. #2
    Senior Tuner Higgs Boson's Avatar
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    -3.0

  3. #3
    Quote Originally Posted by Higgs Boson View Post
    -3.0
    Just curious why - 3.0? why is it better to pull fuel than add it?

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    Senior Tuner Higgs Boson's Avatar
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    yes because if trims are adding fuel it will carry over into PE when you go WOT and make your AF ratio artificially rich and negative trims do not.

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    Advanced Tuner =fast='s Avatar
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    Not to hijack but I have question on this, Higgs can I tune lets say the same car or a cam and headers 2010 camaro using MAF only with the STFT on? Can I tune the car on the cruise mode and WOT mode having just the MAF only with the STFT on?

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    Senior Tuner Higgs Boson's Avatar
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    The MAF table is the MAF table.

    You can use STFT, LTFT, or a wideband in open loop (or a mixture of all of them) to tune it for part throttle but you will need to use the wideband in open loop to tune for full throttle/PE.

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    Advanced Tuner =fast='s Avatar
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    Sorry for the late reply, So I can tune part throttle with the mixture of the stft/ltft, but at WOT it has to be in open loop.
    Do I have to set my file in open loop? What I have read its that when you go WOT the sensors shut down and it's open loop I don't know if it's correct.

    I tune my brothers camaro 2010, I put the file in open loop MAF only and tune the part throttle and WOT. I left the file In open loop it's been running good, the car has a wodeband gauge and it's been running good. My question is since it tune in open loop can I go back to close loop and my airfuel won't change?

  8. #8
    Senior Tuner Higgs Boson's Avatar
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    in theory, yes.

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    Quote Originally Posted by =fast= View Post
    Sorry for the late reply, So I can tune part throttle with the mixture of the stft/ltft, but at WOT it has to be in open loop.
    Do I have to set my file in open loop? What I have read its that when you go WOT the sensors shut down and it's open loop I don't know if it's correct.

    I tune my brothers camaro 2010, I put the file in open loop MAF only and tune the part throttle and WOT. I left the file In open loop it's been running good, the car has a wodeband gauge and it's been running good. My question is since it tune in open loop can I go back to close loop and my airfuel won't change?
    In closed loop the computer will try to maintain lambda = 1. It will constantly move slightly leaner than lambda=1 and then slightly richer than this (o2's will cycle). In PE fueling should be the same as you see now.. in theory anyways.
    Post a log and tune if you want help

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    Advanced Tuner =fast='s Avatar
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    What way you like to tune them, open loop or closed loop?
    Last edited by =fast=; 09-08-2015 at 12:38 AM.

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    I have no idea what you just tried to say
    Post a log and tune if you want help

    VCM Suite V3+ GETTING STARTED THREADS / HOW TO's

    Tuner by night
    CPX Tuning
    2005 Corvette, M6
    ECS 1500 Supercharger
    AlkyControl Meth, Monster LT1-S Twin, NT05R's
    ID1000's, 220/240, .598/.598, 118 from Cam Motion

    2007 Escalade, A6
    Stock

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    Quote Originally Posted by schpenxel View Post
    I have no idea what you just tried to say
    Got you all
    Ok to make it short, To tune a car the right way when its been modded with a cam, procharger, nitrous etc.. You will have to calibrate the MAF table? When i calibrate the MAF table i put the file in open loop and MAF only, Get my scanner and log AFRerror.

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    lol, I understand the content.. just not the grammar

    Yes you would want to adjust the MAF table(s). You can do closed loop areas either way.. fuel trims in closed loop or wideband in open loop. Should get basically the same result. Obviously once in PE you'd have to use the wideband. It's probably quicker to do it in open loop though.
    Post a log and tune if you want help

    VCM Suite V3+ GETTING STARTED THREADS / HOW TO's

    Tuner by night
    CPX Tuning
    2005 Corvette, M6
    ECS 1500 Supercharger
    AlkyControl Meth, Monster LT1-S Twin, NT05R's
    ID1000's, 220/240, .598/.598, 118 from Cam Motion

    2007 Escalade, A6
    Stock