KTuner MAF Scaling Help

PNW_FC3

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Hello CivicX brothers and sisters,

Can anyone provide help/info on MAF scaling for my SI. Currently running a FBO/flex-fuel set-up in my car and my STFT's/LTFT's are both hovering around the -9 to -11 range. I found a great video posted by Caraddict on YouTube essentially walking through the process of how to scale your MAF. Here's the link:



My question to the community would be, what is the mathematical formula or calculation used to get the proper g/s value based on the calculated average STFT value for a particular Hz range? I ask because the gentleman in the video used an excel spreadsheet to calculate his values but in this particular case his vehicle was a non-SI which uses voltage instead of hertz.

I'm new to all this so forgive me if my post/question comes off as lacking, I'm a network engineer by trade but I've always had a deep interest to dabble in the world of ECU tuning. Thanks for your help guys!
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You can see STFT or LTFT vs MAF.Hz in a scatter plot and work from there. Keep in mind if using a flex fuel kit that could be an adjustment over what KTuner is adding for the flex fuel and you could potential just alter the flex fuel fueling scale directly. Easy to check whether you have the same trims with less Ethanol in the system.
 
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PNW_FC3

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@KTuner this is what I have and also a copy of my datalog. So based on this data plot, how do I determine the correct G/S value?

Honda Civic 10th gen KTuner MAF Scaling Help Scatter Plot.PNG
 

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@KTuner this is what I have and also a copy of my datalog. So based on this data plot, how do I determine the correct G/S value?

Scatter Plot.PNG
Work with percentages. If the car is showing an STFT trend of -2% at some point in the MAF scale, apply a -2% adjustment to the g/s.
 
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PNW_FC3

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Thanks @360glitch that’s what I was looking for!!! Can this methodology be applied when scaling using STFT as well? And with regards to capturing data. Can I simply just throttle through the entire rev range while parked or is it better to do it when in gear? I ask because the last data log session I conducted, I wasn’t exactly sure.
 

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Thanks @360glitch that’s what I was looking for!!! Can this methodology be applied when scaling using STFT as well? And with regards to capturing data. Can I simply just throttle through the entire rev range while parked or is it better to do it when in gear? I ask because the last data log session I conducted, I wasn’t exactly sure.
Yes sorry I should have stated STFT, not LTFT. I will go back and edit my original post.

You need to set your LTFT min and max to 0 while doing this to get accurate data.

You need to drive the car under load. I would recommend 15-20 minutes of part throttle stop and go driving, simulating normal use.
 
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PNW_FC3

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Yes sorry I should have stated STFT, not LTFT. I will go back and edit my original post.

You need to set your LTFT min and max to 0 while doing this to get accurate data.

You need to drive the car under load. I would recommend 15-20 minutes of part throttle stop and go driving, simulating normal use.

Ok got it, thanks. So after I apply the new configurations for MAF scaling, do I just leave the LTFT at 0?
 

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Or could get it custom tuned for best overall everything lol not just fuel trims.
 

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Ok got it, thanks. So after I apply the new configurations for MAF scaling, do I just leave the LTFT at 0?
No, return it to the default setting.
 


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PNW_FC3

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No, return it to the default setting.
@360glitch thanks for your help! My LTFT is consistently staying around 0 to -1 now and my STFT are averaging about between 3 to -4ish. Couldn't have done it without your info! This was definitely a fun learning experience!
 

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Work with percentages. If the car is showing an STFT trend of -2% at some point in the MAF scale, apply a -2% adjustment to the g/s.
i have just come across this thread as i am having some issues getting my fuel trims and AFR correct and this example helps alot!. so from looking at the scatter plot i can see my stft and MAF voltage (uk owner) and the trend has set to pretty much zero so in order for me to bring the outer dots into the trend line do i use the CSV log and calculate the mean value then + - the % at which ever g/s value and will this stop my trims from jumping up and down as im driving? and for the MAF voltages for 3.8v to 5v because my engine runs in status 4 do i have to calculate the avaerage AFR value then work out the difference it is from my target afr for e.g 10.96 +2% = 11.2 AFR target ?

also do you have to do anything with the WOT enrichment table or is that better off left alone?

cheers!
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