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Thread: performing a closed loop maf cal!

  1. #21
    Join Date
    Jun 2009
    Location
    Newcastle
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    1,413

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    Yeah. My understanding is at the points when your desired and actual lambda are the same and the throttle position/maf volts are steady the car is in closed loop and thats why the LTFT data at that point is whats needed.
    I dont want to confuse the process of ATR method though.

  2. #22

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    yeh well i appreciate your help so far anyway mate, i think i need to go back and read read, its all.abit overwhelming lol, theres so much to learn

  3. #23
    Join Date
    Jun 2009
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    Newcastle
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    1,413

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    Agree, Im on the MAF cal journey atm lol

  4. #24

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    im just over 8% threshold cobb recommends, i wonder if its worth just leaving it

  5. #25
    Join Date
    Jun 2009
    Location
    Newcastle
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    1,413

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    Prob not.

  6. #26

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    i had another attempt today and as soon as i hit 83ish gs in every log i go open loop(ltft goes to 0) this happens around 4700 4800 rpm. any suggestions guys? do i need to get on the throttle abit harder alittle sooner, i tend not too, to try keep it in close loop, then as i aproach redline i dont have enough gs and it goes into open loop

  7. #27

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    ok ive been doing some more reading and im not so sure now that iam going into open loop.Heres what happens that made me originally think i was, at around 83 - 86 ish gs my ltft goes to 0 then i read someone else was having a similar issue and some suggested logging closed loop to.verify if they were infact going into open loop. If my closed loop is 512 against all my 0 ltft is this still in cl even know my ltft is 0?

  8. Default

    You'll see the CL column transition numbers when going from CL to OL... Can't remember whether it goes from 512 to 1024 or vice versa. Have a closer look at the log.

  9. #29

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    thats why i ask, because im only doing a cl log im only loging as much as i need too, not everything all i need to know.if i have 0 ltft but the closed loop is still 512 is that still in cl?

  10. Default

    Have a close look at your log. Ill assume that by doing a maf cal run that you're starting the logging in closed loop mode. Start at the top of the log and scroll down the CL column, keep scrolling until you see a change in numbers. At that point go across to the LTFT column. If you also see a change in LtFT numbers from whatever (say 1.6%) to zero, you've entered open loop at that point.

    Also, short term trims go to zero in open loop as well...

  11. #31

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    ok i have verified from a reliable source on msf that because you are never likely to be in the 80gs region in cl for a extended period of time if ltft goes to 0 it can just mean there is no trim, however to confirm that u log stft aswell and if at that point in the log it is also 0 it has gone into open loop. Im now fairly confident i should get a decent log tomorrow to calibrate from, in some of my logs the gs in the odd row would go up then the next one go down then up again? i asume a steady increase is best but how perfect does it need to be for a decend calibration?

  12. #32
    Join Date
    Feb 2012
    Location
    Wollongong
    Posts
    846

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    Just keep a steady foot around 25% make sure you log AFR. In your log if your in C/L your AFR should stay around 14.7. You can do C/L logs in any gear too. In 6th on the freeway might be easier for you to do the higher breakpoints as you have more airflow at lower revs. You can just do single breakpoints at a time easily that way, you dont have to do them all in the same log.

    Sent from your mums phone

  13. #33

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    i just need somone that is experienced to look at the log i used to perform my closed loop maf cal and also the saved map and tell me if everything looks ok before i flash it @sarcastic one

    Much appreciated
    Attached Files Attached Files

  14. #34
    Join Date
    Feb 2012
    Location
    Wollongong
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    846

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    Quote Originally Posted by mymps11 View Post
    i just need somone that is experienced to look at the log i used to perform my closed loop maf cal and also the saved map and tell me if everything looks ok before i flash it @sarcastic one

    Much appreciated
    Looks good to me, MAF curve is smooth enough. Flash it, drive till you have learned trims and do another MAF cal.

  15. #35

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    what about the log? everyone is saying you should only need 20 - 35% accelerator pedal pos to have the gs increase linearly, to have my gs increase slowly and constant i am up to 35% accelerator pedal pos by 80ish gs. Would this affect the readings im entering into atr for the maf cal making it incorrect? Ive only calibarated up to 3.09 volts on that maf curve so keep that in mind! the gs beyond 3.09 volts are ots. After 3.09 volts my ltft go to zero which could suggest open loop, so i added stft to the log, if you have a look they arnt going to 0 at that point, so another question i have is can i then treat the - value stft beyond 3.09 volts as closed loop and use them to scale my maf up to 100gs? or should leave that for the wot maf cal?

    I hope that makes sense, im still getitng use to all this!

    Cheers mitch

  16. #36
    Join Date
    Feb 2012
    Location
    Wollongong
    Posts
    846

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    No you don't use the STFT's. I would just run a few more logs, you should always do at least 3 and compare them. You'll get the info you need if you keep trying. What % Pedal Pos you get is just a guide. As long as it's just enough to keep increasing revs and to get your MAF g's high enough. Don't be too paranoid about getting them perfect as long as you get them within -8/+8% you wont notice any difference.

  17. #37

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    ive done 3 logs and they seem consistant, the way i interpret my log is when ltft go to 0 at 83.62gs then stft goes back to -2.34, so is the car still in closed loop at that point and the only reason the ltft when to 0 is because there is nothing learnt in that breakpoint?

  18. #38

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    well guys ive flashed my maf cal and im within 2% + - not bad for a first attempt eh!

  19. Default

    thats as good as you'll get it (within abs 2%), well done.

  20. #40

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    yeh cheers mate, should i calibrate wot once ive.got.more kms on this flash?

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