HOW TO CALIBRATE YOUR MAF! With An Example

[dougefresh_]

Originally Posted by Ziggo As said before, it helps to apply the smooth throttle fix or be using a boost based tune. The OTS maps have some pretty brutal surging.

I tried the smooth throttle fix when I first got into ATR way back when, but I didn't care for it. I think it's just that I've gotten so used to driving the car with the stock mapping it just feels natural to me (see above logs). I also think this is more of a MS3 thing and helps with traction iirc? I don't know many MS6'ers that use it. Regardless, the mapping on the two cars is the same stock. If you use the 'smooth throttle fix' the values for APP in my post above will obviously be different... they will be higher.

[Ziggo]

Originally Posted by dougefresh_ I tried the smooth throttle fix when I first got into ATR way back when, but I didn't care for it. I think it's just that I've gotten so used to driving the car with the stock mapping it just feels natural to me (see above logs). I also think this is more of a MS3 thing and helps with traction iirc? I don't know many MS6'ers that use it. Regardless, the mapping on the two cars is the same stock. If you use the 'smooth throttle fix' the values for APP in my post above will obviously be different... they will be higher.

It might just be a ms3 thing, Cobb might not have dicked with the mapping like they did on the ms3 maps. it's not really a traction issue as much as its a surging issue. It makes the car "feel" faster for your average idiot because "you just tap the pedal and it flies" but really all it is just a twitchy throttle.

[dougefresh_]

Originally Posted by Ziggo It might just be a ms3 thing, Cobb might not have dicked with the mapping like they did on the ms3 maps. it's not really a traction issue as much as its a surging issue. It makes the car "feel" faster for your average idiot because "you just tap the pedal and it flies" but really all it is just a twitchy throttle.

The mapping is the same (steep curve, etc), but I think the effect is more pronounced with fwd. IDK... My pedal is sensitive too, but I've just gotten used to feathering it. It actually felt really odd with it linear when I tried it, so I switched it back to stock. But I totally understand why people do it, and many people love it. Just a matter of preference I guess.

[Boosted Beluga]

I calibrated my MAF today but had a quick question. My LTFT for voltage was 2.34 for 1.5 to 2.12V, then 6.25 for 2.14 to 2.39V, then 4.79 for 2.4V for the rest of the way. Now my question is these are not the normal breakpoints obviously but this is the way I did it since it was so drastic per "breakpoint". Is this ok? The car feels soo much better now but I want to get some more miles on the flash so I can check the LTFT. If this is completely wrong let me know and I will change it.

Thank you.

[dougefresh_]

Originally Posted by black beast I calibrated my MAF today but had a quick question. My LTFT for voltage was 2.34 for 1.5 to 2.12V, then 6.25 for 2.14 to 2.39V, then 4.79 for 2.4V for the rest of the way. Now my question is these are not the normal breakpoints obviously but this is the way I did it since it was so drastic per "breakpoint". Is this ok? The car feels soo much better now but I want to get some more miles on the flash so I can check the LTFT. If this is completely wrong let me know and I will change it. Thank you.

Keep in mind the breakpoints are based on maf g/s, not maf volts, so the volts may vary a bit. I'm not looking at any logs, but it sounds like you did the maf cal right. See what the FT's are like after the map is broken in & keep up the good work!

[Boosted Beluga]

I'll up load a data log later. But thank you

[dougefresh_]

Originally Posted by black beast I'll up load a data log later. But thank you

NP. I may not be able to look at it, because I'm rocking Office 2003 Pro w/ a new laptop (win 64bit), and the compatibility is minimal at best, lol. Why doesn't my cheap ass just upgrade Office?! Because I still have a Tial 38mm EWG and some misc parts from ATP to buy for my BT . Best reason ever!!!! lol

[Boosted Beluga]

Hahaha yeah I'll give you a pass this time. But I can email the log to ya if your interested

[Ziggo]

Originally Posted by dougefresh_ NP. I may not be able to look at it, because I'm rocking Office 2003 Pro w/ a new laptop (win 64bit), and the compatibility is minimal at best, lol. Why doesn't my cheap ass just upgrade Office?! Because I still have a Tial 38mm EWG and some misc parts from ATP to buy for my BT . Best reason ever!!!! lol

Open office FTW.

[dougefresh_]

Originally Posted by black beast Hahaha yeah I'll give you a pass this time. But I can email the log to ya if your interested

I could download it from here, but that may not help. I may go with Open Office in the meantime. Arghh... fuck okay I'll guess I'll download that shit now. I still have to do my taxes, and study for some serious exams, but I'm trying to enjoy a stiff drink & watch some Tosh.0 here.... lol

I submitted this short vid I put together to Tosh.0 the other day... I caught this on the news a few days ago, LOL!!!

YouTube - Muslim Mohawk FTW

YouTube - Muslim Mohawk FTW

Video editing a la dougefresh. I could've made it funnier, but I was rushed.


Unlike the requisite bird's nest beard, apparently the Koran is a little more lax when it comes to hairstyles.

The Four Seasons Kandahar frowns upon you stealing the hotel towels.

The Taliban must not be hitting their recruitment numbers. I'll keep my eyes out for rainbow colored turbans, and ones with the Star of David stitched on. This is how it starts...

[R.MS3]

The OP put some great info for those that want to do a MAF cal. by themselves but IMO, with so many words written, it looks way harder than it really is lol.

I would try to make it more simple since this is the thread most people visit (sticky) so people don't go WTF.

I would also mention that you gotta calibrate the higher part of the MAF curve following your AFR, for OL operation. A lot of people miss this step and wonder why they're running lean and having KR when going WOT.

[dougefresh_]

Originally Posted by R.MS3 The OP put some great info for those that want to do a MAF cal. by themselves but IMO, with so many words written, it looks way harder than it really is lol. I would try to make it more simple since this is the thread most people visit (sticky) so people don't go WTF.

Thanks, I am the OP . If anything, I wish post#49 was first (the dumbed down version), but I edited the OP to refer to it. That post is simple... tuning is NOT. Once you understand the maf cal, however, you've pretty much broken through the learning curve of tuning imo, and everything becomes MUCH easier.

I wrote a lot to explain it as detailed as possible... I can't tell you how many PM's I've got asking me to repeat the same thing or elaborate. Learning tuning takes both time & effort. If one thinks the OP is too long then you're just being really lazy, lol. It is very simple once you understand it, but when you don't it can be very confusing. I always break things down for n0000bs like me, and try to answer every question I think someone may have. That saves me hassle, and helps out many folks that may need an extra point or two reiterated.

I would also mention that you gotta calibrate the higher part of the MAF curve following your AFR, for OL operation. A lot of people miss this step and wonder why they're running lean and having KR when going WOT.

You're definitely right about the OL calibration, but I would be more specific and refer to it as the OL/WOT calibration as to avoid confusion with OL/Part Throttle fueling tables, which should be fine if you calibrated your maf properly. Under wot, your ecu does not use fuel trims as you know... it reads right off the maf. However, this has little to do with them getting KR. While it's true that a rich mixture will help combat KR, I know plenty of people that run 12.0 afrs and get zero KR without meth. Timing, meth, etc... are other issues, however, for other threads.

The reason people miss these steps is because they're too lazy to read the fucking Helpfile. And not to be a dick, but if you're too lazy to read the helpfile (or the OP is too long) and you go boom... then that's what you get for messing with tuning without doing your homework. I read it at least 3x front to back. I was surprised there wasn't a "how to" already for the maf cal, bc once you understand it, it is simple, but it causes a lot of confusion at first. I haven't looked at the Helpfile in over 6+ months, but the next step iirc is "establishing proper safe fuel curves," which deals with calibrating your maf at wot. I meant to do a "how to" for that, but never got around to it, and my wot afrs were spot on.

Sorry if my explanation for the OP was longer than it, but ^^that is the truth

[Boosted Beluga]

here is the data log I used to calibrate my MAF.

[dougefresh_]

(From post 78):
The 5 different LTFT breakpoints are:
0 – ~5 grams/sec
~5.01 – ~18 grams/sec
~18.01 – ~31 grams/sec
~31.01 – ~69 grams/sec
~69.01 grams/sec – full sensor range

Your log shows it following this perfectly. You don't "appear" to have a breakpoint at 69 g/s, but that's just because your FT's happen to be the same for the last two breakpoints @ 4.69

I still haven't downloaded Open Office Yet.. I'm on my old laptop, lol

[indianaryan]

Originally Posted by djuosnteisn You want to adjust all across the board. Or the method i like to use... is adjust the 2.6 - 5 volt range necessary to make your OL afr's match your targeted afr's. For instance. If you got WOT, and your afr's are hitting 12's across the rpm range.. and you OL fuel tables are requesting 11.5's... then you need to multiply the OL portion of the MAF table (2.6V - 5V) by 1.043. That will bring your WOT afr's down. It's very similar to using the LTFT + STFT values in closed loop, but basically your using the % difference between desired and measured wot AFR's. Hope this helped.

Does anyone else think mentioning something about the 2.6V-5V section of the MAF table should be mentioned in the OP? I think it might be helpful to mention that when doing a MAF Calibration, you should be aware that you might have to go back to the MAF table and adjust if the WOT AFR is off. Doing a MAF Calibration doesn't necessarily fix any issues with the actual AFR being off from what the OL fuel tables are requesting.

BTW, thanks for the write-up. It's so much easier to follow than the helpfile.

[Boosted Beluga]

Originally Posted by dougefresh_ (From post 78): The 5 different LTFT breakpoints are: 0 – ~5 grams/sec ~5.01 – ~18 grams/sec ~18.01 – ~31 grams/sec ~31.01 – ~69 grams/sec ~69.01 grams/sec – full sensor range Your log shows it following this perfectly. You don't "appear" to have a breakpoint at 69 g/s, but that's just because your FT's happen to be the same for the last two breakpoints @ 4.69 I still haven't downloaded Open Office Yet.. I'm on my old laptop, lol

Ok cool I just followed the log. I think I have to adjust it some more but I want to get some more miles on the tune 1st.

[kahunab14]

Ok, I feel stupid but I have to ask. I understand what I am suppose to do by comparing my logs and the table in ATR...I understand the math essentially.

What I DONT understand is what you have to do AFTER you do the datalog, but PRIOR to making the ATR math adjustments. So here are my questions...but it would be really helpful is someone could just write a very simple step by step guide of what you do after you do the datalog but before the actual multiplier adjustments.
1) After you tak ethe datalog, are you just using that for reference or do you have to input the log into ATR for some reason?
2) Do you need to upload the current tune that is one the car from the accesport, from the accessport manager, or dont you need to do this at all?

Thanks

[rfinkle2]

Originally Posted by kahunab14 Ok, I feel stupid but I have to ask. I understand what I am suppose to do by comparing my logs and the table in ATR...I understand the math essentially. What I DONT understand is what you have to do AFTER you do the datalog, but PRIOR to making the ATR math adjustments. So here are my questions...but it would be really helpful is someone could just write a very simple step by step guide of what you do after you do the datalog but before the actual multiplier adjustments. 1) After you tak ethe datalog, are you just using that for reference or do you have to input the log into ATR for some reason? 2) Do you need to upload the current tune that is one the car from the accesport, from the accessport manager, or dont you need to do this at all? Thanks

First and foremost, the stupid thing to do is NOT ask.

1) your log gives you maf g/s breakpoints and the corresponding "chunks" / groups of LTFT (think of them as errors in a way)
2) for every point up to each "breakpoint" e.g. 0-5.7g/s , you will see a repeating "error" i.e. LTFT reading horizontally.
3) Your goal is to use ATR to correct for the LTFT "errors"
4) The log gives you the LTFT (you will see repetitive chunks of LTFT numbers next to corresponding "chunks" aka breakpoints of maf g/s.
5) Entire chunks of MAF breakpoints and corresponding LTFT "errors" are 0-5.7 g/s, 5.8-18 g/s, 18.1-30 g/s, 31-77 g/s and finally 78 g/s to max grams per second.
6) look across @ 0-5.7g/s in your logs. e.g. if the chunk of ltft's are 6's, you will take that info, and multiply your corresponding g/s by 1.06 in ATR. If those LTFT values are -6, you will multiply in atr the g/s up to 5.7 g/s by .94.
7) each chunk of maf g/s aka breakpoints and the corresponding "chunk" of ltft's must be used to find what to multiply g/s by in atr.

PM ME IF YOU NEED A HAND.

@indianaryan , I have seen the guys correct there AFR's in the high end of the maf g/s this way:

italics from the atr helpfile:
This comparison only relates if you have an intake system that is other than stock; if your dictated A/F is 11.0 and you measure 12.0 in the exhaust
stream, then you will want to add (+) grams/sec for the MAF voltage that corresponds for that RPM and load point. The specific adjustment for the above
situation should be multiplying the corresponding MAF flow grams/sec by 1.0909 = 12/11. You should be measuring very close to the same Lambda (A/F
Ratio) in your exhaust stream that you have dictated in your Fuel OL/WOT Commanded EQ (No Knock) table.

[dougefresh_]

Originally Posted by kahunab14 What I DONT understand is what you have to do AFTER you do the datalog, but PRIOR to making the ATR math adjustments.

You turn on your laptop, lol.

1) You're using it as reference. The maf tables A + B have the stock values in there. You see where your car is adding (+LTFT) or subtracting (-LTFT) fuel.... that is what the datalog tells you. Reread OP & read the helpfile.

2) If you're just starting out, the maf cal is your first step. Once that is done, you save that map with the maf tables A & B changes that you made. Then you move on to the next step, which I didn't get into because people have a hard enough time with the first part.

Originally Posted by rfinkle2 First and foremost, the stupid thing to do is NOT ask. I have seen the guys correct there AFR's in the high end of the maf g/s this way: italics from the atr helpfile: This comparison only relates if you have an intake system that is other than stock; if your dictated A/F is 11.0 and you measure 12.0 in the exhaust stream, then you will want to add (+) grams/sec for the MAF voltage that corresponds for that RPM and load point. The specific adjustment for the above situation should be multiplying the corresponding MAF flow grams/sec by 1.0909 = 12/11. You should be measuring very close to the same Lambda (A/F Ratio) in your exhaust stream that you have dictated in your Fuel OL/WOT Commanded EQ (No Knock) table.

Yup, it's right in the Helpfile. Read it folks!

[kahunab14]

Hey, first off, thanks for the responses! Sorry I am an idiot...the scary thing is I am an engineer too Maybe that is why I understand the math/multipler part of the process but nothing else ha. Ok, so lemme see if I now understand the parts that I am unclear on...just tell me if I have this down.

1) Take proper MAF datalog. Done, yay.
2) Using the AP manager where my tunes are stored, load the stage 2 OTS tune that is currently flashed in my car into the ATR. (not sure what mouse clicks to make to do this yet)
3) Somehow pull up the map that I just loaded. (again, not sure what mouse clicks to make to do this yet)
4) Make the MAF adjustments...this I undestand
5) Save the adjusted tune to a different file name within the AP manager.
6) Load the adjusted tune to the AP itself.
7) Re-flash the car with the adjusted tune.

Do I have that now? Anything I said wrong?

Thanks

[rfinkle2]

Originally Posted by kahunab14 Hey, first off, thanks for the responses! Sorry I am an idiot...the scary thing is I am an engineer too Maybe that is why I understand the math/multipler part of the process but nothing else ha. Ok, so lemme see if I now understand the parts that I am unclear on...just tell me if I have this down. 1) Take proper MAF datalog. Done, yay. 2) Using the AP manager where my tunes are stored, load the stage 2 OTS tune that is currently flashed in my car into the ATR. (not sure what mouse clicks to make to do this yet) 3) Somehow pull up the map that I just loaded. (again, not sure what mouse clicks to make to do this yet) 4) Make the MAF adjustments...this I undestand 5) Save the adjusted tune to a different file name within the AP manager. 6) Load the adjusted tune to the AP itself. 7) Re-flash the car with the adjusted tune. Do I have that now? Anything I said wrong? Thanks

In ATR,
1) hit File>load map
2) go to sensor calibration tables in the pane to the left.
3) make the changes in maf table A

You are good to go with the above steps.

I think you may be "overthinking" it a bit, but that is understandable considering it is a $25,000 machine.

LET US KNOW HOW YOU MAKE OUT!

[dougefresh_]

Originally Posted by kahunab14 Hey, first off, thanks for the responses! Sorry I am an idiot...the scary thing is I am an engineer too Maybe that is why I understand the math/multipler part of the process but nothing else ha. Ok, so lemme see if I now understand the parts that I am unclear on...just tell me if I have this down. 1) Take proper MAF datalog. Done, yay. 2) Using the AP manager where my tunes are stored, load the stage 2 OTS tune that is currently flashed in my car into the ATR. (not sure what mouse clicks to make to do this yet) 3) Somehow pull up the map that I just loaded. (again, not sure what mouse clicks to make to do this yet) 4) Make the MAF adjustments...this I undestand 5) Save the adjusted tune to a different file name within the AP manager. 6) Load the adjusted tune to the AP itself. 7) Re-flash the car with the adjusted tune. Do I have that now? Anything I said wrong? Thanks

Lol, happy to help and I was just busting your chops .

2) Open the AP manager. On the main screen you can change the filter to "maps" or just look for the file. Select it and click the "move files to computer" icon. Put it on your desktop if that makes it easier.

3) Open the ATR software, click "file" then "load map." Select the map you just saved off your AP in step 2 above. Click open.

You got the rest

[kahunab14]

All I have to say is wow! I was at +5 to +9 ltft's throughtout the g/s band, and I corrected using these instructions.

Lemme give you a little background first:The OTS map for Stage 1+SF was buttery smooth (and happen to have low ltft's by coincidence...like +-2 without me even calibrating). Then I went Stage 2 and things got kinda jumpy on and off the throttle...didnt sound as good as I thougth the exhaust should just rough all around. Also, it was very slow/sluggish feeling from about 2,000 to 3,000 rpms. Now after just reflashing post calibration I was amazed. On and off the throttle felt BETTER than the stage 1 map, so smooth, exhaust sounds so good! And I just got on it a few times, not WOT cause im letting the trims settle if they need, but the car just PUUUULLLLLS ... i realized I was enjoying it so much on my ride to work I was driving way too fast and had to back off. Thanks to everyone, I love you guys! Hopefully this will fix my mastegate maxing out issue...

[Boosted Beluga]

I was thinking yesterday, why dont we do the MAF CAL in 3rd gear? I think it might be smoother to get a more accurate reading? Yeah it will take longer and you would need a longer road but maybe be worth it? Maybe I'm thinking nonsense?

[dougefresh_]

Originally Posted by black beast I was thinking yesterday, why dont we do the MAF CAL in 3rd gear? I think it might be smoother to get a more accurate reading? Yeah it will take longer and you would need a longer road but maybe be worth it? Maybe I'm thinking nonsense?

You could do it in third... it may be more difficult or it maybe easier... idk... I never tried. As long as your getting clear breakpoints where they should be (per maf g/s breakpoints), you should be fine. Trust me though, 2nd gear is super easy once you get the hang of it. I'm done in 5 mins w/ two perfect logs. Go for 3rd though and let us know how you make out if 2nd is giving you a hard time.

Also on a side note: One thing that will cause issues is if your maf is dirty. It's easy to clean with maf cleaner from any autoparts store ($7 or $8). Just be very careful because the sensor is very fragile.

[Boosted Beluga]

I'm not having any trouble I was just wondering if it would benefit us more then 2nd gear is all. MAF cleaner works great

Also on a side note: would be best to clean the MAF before you calibrate it.

[dougefresh_]

As long as you have clear breakpoints (i.e. not tons of maf volts overlap for a given LTFT) then it shouldn't matter. That's why I say to do a couple maf g/s tests so you can figure out the 'best' maf volts to use when applying the corrections. My maf is pretty clean, and my breakpoints are clear. I think I talked about this in the OP though, and described what to do. When I get a chance, I'll update the OP with instructions w/ how to calibrate your wot afrs. Although it has been described a couple times already in later posts, lol. There is also calibrating your maf around idle, but it's not as big of a deal, and my idle was typically good. I cover that too. I hadn't bc it's described well in the helpfile, and is less confusing than calibrating your maf.

[Boosted Beluga]

I understand how to do everything. Well except the wot part. But thats later. I was just thinking if 3rd gear would any better is all.

[Ziggo]

Originally Posted by black beast I understand how to do everything. Well except the wot part. But thats later. I was just thinking if 3rd gear would any better is all.

Thats easy.

Log MAF voltage, AFR and rpm

Pull a 4th gear wot log

In your datalog, add a new column for commanded AFR and enter the AFR values from your map the correspond to the RPM rows from the log

Add a new column for "correction factor" and divide the actual by the commanded for each row.

Apply the correction factors to your maf tables A and B by multiplying the existing values for the maf volts my the correction factor.

If you are crazy like me you can take several logs interpolate between the data points so you have a row for every maf voltage above about 70g/s average the correction factors and apply it individually to every column in the maf sensor calibration tables.

[polkcountydude]

I figured that I didn't need to calibrate my MAF, because I only have a CS SRI+TIP. However, I was curious to see my fuel trims. So I ran several logs - took me a few times to get the acceleration right - and found that I only have the 18 g/s breakpoint. Before that breakpoint, my LTFT is 0 and after that breakpoint it is -0.78. I'm new to tuning and am not sure if this situation is unusual. My completely uneducated guess is that the OTS CS SRI+TIP map is already calibrated. However, given changing weather, vehicles, etc., there should be some variation, right?

[Boosted Beluga]

Your MAF is fine. I wouldn't worry about it until you do exhuast and/or intercooler

[dougefresh_]

OP is a douche

[Boosted Beluga]

Originally Posted by dougefresh_ OP is a douche

Yeah thats what I hear. He thinks he's badass with his twin scroll 3076 turbo and shit.

Ok im jealous of you lol

[Jasper_3MPS]

Oke my question now is how do i calibrate my Mazda 3 MPS whit out a AP... i do have a DH but no way to re write the MAF table... or do i???

[Ziggo]

Originally Posted by Jasper_3MPS Oke my question now is how do i calibrate my Mazda 3 MPS whit out a AP... i do have a DH but no way to re write the MAF table... or do i???

It's pretty obvious, but you have to have an AP.

[Jasper_3MPS]

Yes i know for the methode i have to use the AP but thats the problem i have EURO Mazda 3 MPS and i cant use the AP...

if i could have used a AP on my car i would have bought it... But

does that mean i would have the use ECUTEC or MazdaEdit??? just hoping there is a other way to calibrate the MAF since i have my doubt that its not cause iam seeing LTFT of 20+.... so...

[rfinkle2]

Originally Posted by Jasper_3MPS Yes i know for the methode i have to use the AP but thats the problem i have EURO Mazda 3 MPS and i cant use the AP... if i could have used a AP on my car i would have bought it... But does that mean i would have the use ECUTEC or MazdaEdit??? just hoping there is a other way to calibrate the MAF since i have my doubt that its not cause iam seeing LTFT of 20+.... so...

An Ecutek tuner will be able to fix your trims and tune your car.

[dougefresh_]

Originally Posted by Jasper_3MPS Yes i know for the methode i have to use the AP but thats the problem i have EURO Mazda 3 MPS and i cant use the AP... if i could have used a AP on my car i would have bought it... But does that mean i would have the use ECUTEC or MazdaEdit??? just hoping there is a other way to calibrate the MAF since i have my doubt that its not cause iam seeing LTFT of 20+.... so...

Maybe Versatuner? Search the forums/google for that. I know they were beta testing all over the place, not just the states. GL

[Eric28243]

All of this hubbub for a MAFcal. I've yet to do it, but I've got a current OTS map with similar mods to what I have installed. I'm hoping it will hold for now until my SRI gets here. When the time comes, I'll tackle it. Till then, I'm just hoping I can figure it out. This might be a dumb question, but so long as the knock sensors aren't going haywire, running a non-optimized, non-maf-calibrated map after the 50-mile break-in period won't hurt the car will it? I hooked the AP up for shits since I don't want to go through the trouble of calibration with the fujita cai if I'm just getting a new intake. The fuel trims are pretty bad but after it warms up, there are no knocks to report.

[wolly6973]

Why would we bother with it if it doesn't hurt the car not to do it??
Just because there is no KR doesn't mean everything is peachy.

Do a MAF cal log, and see if you are close enough. If your trims are wacky, just do it. It's not that tough once you do it once, and your car will run safer and more efficiently.