Calibrating the MAF For Dummies?

[Parkeway]

Ok. I've poked, prodded and essentially become dangerous with ATR on the AP. But what I haven't figured out is how to calibrate my mods (and MAF airflow) for the AP.

My goal would be to use one of the Stage 1 maps and tweak it with my airflow (Nano, Inlet, TMIC, Test Pipe) settings.

I've spent the last few days going over Cobb's spreadsheet for calibration, but I can't make heads or tails of it!!! (is it obvious I was an English major and still hate math?)

Anyway, has anyone put together a "Calibration for Dummies" to help numb skulls like me?

 

[dread]

check out the *******************.***
Ignore the spread sheets. All you need to do is log long term and short term fuel trims, mass air flow and maf volts. When your logging have mass air flow on the live data screen. accelerate slowly and make sure your airflow reaches 100g/s.

The tables you need to modify in ATR are maf tables a and b. The top row is maf volts and the bottom row is your mass airflow. The bottom row is what is adjusted.

look at your logs there should be five ltft values or breakpoints that correspond to different mass airflow values. For example, idle is between 2-5 grams/sec. If your idle ltft's are +10 you would highlight the mass airflow values (in the bottom row) that are between 2 and 5 and hit M which allows you to multiply the values. A box will come up and enter 1.10, indicating that you are adding 10% more fuel. If the ltft was -10 you would multiply by .90.

Other breakpoints are 5-16, 16-28, 28-77, 77-the end.

 

[Parkeway]

You da man

 

[MS3Zoom24]

Dread your face should come on the ATR software as a support line!!!

 

[ericrapp]

You are a good man person, dread.

 

[DaleNixon]

I think dread is a pretty cool guy.

 

[unicef]

So is using ATR to tune a base map to your car really that easy? I have my AP and ATR arriving in about a week, and I'm looking forward to playing around (not literally playing around, but you know what I mean)... Thanks for the explanation!

 

[Speed3Rookie]

Its a little involved...the "other" forum has a bit more indepth info for potential users.
Posted via Mobile Device

 

[Speed3Rookie]

check out the *******************.***
Ignore the spread sheets. All you need to do is log long term and short term fuel trims, mass air flow and maf volts. When your logging have mass air flow on the live data screen. accelerate slowly and make sure your airflow reaches 100g/s.

The tables you need to modify in ATR are maf tables a and b. The top row is maf volts and the bottom row is your mass airflow. The bottom row is what is adjusted.

look at your logs there should be five ltft values or breakpoints that correspond to different mass airflow values. For example, idle is between 2-5 grams/sec. If your idle ltft's are +10 you would highlight the mass airflow values (in the bottom row) that are between 2 and 5 and hit M which allows you to multiply the values. A box will come up and enter 1.10, indicating that you are adding 10% more fuel. If the ltft was -10 you would multiply by .90.

Other breakpoints are 5-16, 16-28, 28-77, 77-the end.

hmm...i'm a little confused on how to calculate the values I need to change.
for instance what numbers to use if my log shows -4.7 at idle(means i need to pull fuel correct?), +2.3 part throttle (means i need to add fuel?).
is there some sort of table to use to figure out what numbers to plug in to get this right?

thanks

 

[leadf00t]

hmm...i'm a little confused on how to calculate the values I need to change.
for instance what numbers to use if my log shows -4.7 at idle(means i need to pull fuel correct?), +2.3 part throttle (means i need to add fuel?).
is there some sort of table to use to figure out what numbers to plug in to get this right?

thanks

A -4.7 means the ecu is pulling fuel, so you are running rich. Mine is doing the same thing, but I have not had a chance to drive around town for 50 miles to log my trims, and work on the maf calibration yet.

 

[Mid_Life_Crisis]

hmm...i'm a little confused on how to calculate the values I need to change.
for instance what numbers to use if my log shows -4.7 at idle(means i need to pull fuel correct?), +2.3 part throttle (means i need to add fuel?).
is there some sort of table to use to figure out what numbers to plug in to get this right?

thanks

I`m still saving my pennies for my own AP, but I have been reading every post about them that I have seen so I`ll have a clue when the time finally comes.
I think you need to stop thinking of the MAF tables in terms of adding or pulling fuel. What you are doing is teaching the ecu what the different MAF voltages really mean. If the LTFT numbers are in the negative, it means that the system is pulling fuel - because the MAF is reading high. Think about it, the MAF says, hey we got 10 liters of air per second coming in (number off the top of my head) when it is really 8 and the fuel table looks at all the other inputs and dumps in the correct amount of fuel for 10. But over time, the ecu figures out through monitoring the O2 sensor, that this is too rich and starts pulling fuel, which shows in the LTFT table.
So you tell the ecu this by decreasing the value in the MAF table for that voltage range. Now it knows that when it sees that voltage, it means there is less air moving than it used to believe. The LTFTs will self adjust for this corrected air volume and eventually stop pulling fuel to get the correct reading at the O2 sensor. Once you have the LTFTs showing little or no adjustment is being made, it means the MAF is supplying an accurate reading to the ECU and you can start tuning for real on all the other settings. The reason you want to take your time and get this right is obvious: if the ecu does not have an accurate reading of how much air is entering the system, it cannot possibly make any of its other settings correctly.
Once you have the MAF tables set up properly, you can start messing with the fuel tables to tweak your A/F ratio and knock, etc., etc.

 

[leadf00t]

I have a question. The cobb atr manual for maf calibration says to start in
2nd gear at 1500 rpms, and accelerate to 100 grams/sec. Can the 100 grams be achieved without shifting into 3rd ?

 

[dkswim]

man i shold do this sometime...

 

[Speed3Rookie]

I have a question. The cobb atr manual for maf calibration says to start in
2nd gear at 1500 rpms, and accelerate to 100 grams/sec. Can the 100 grams be achieved without shifting into 3rd ?

yes...you will need to apply a slow and steady throttle.

 

[ericrapp]

Mid life it sounds like you are getting prepared very well. I also am subscribed to this educational thread. thanks folks for the good questions and answers.
signed Dummie.

 

[aaronc7]

this is what i use to make my MAF tables. if you copy values from ATR it will round to 2 decimal places (for MAF table)... I like to use exact values and copy them in. anywhere here is the file.

 

[MS3MB]

ya i enjoyed reading this thread. Does anyone have a good website when i could learn how to use atr with the ap and how to tune myself

 

[blacksheepms3]

So it's risk changing the values. I kinda wanna play around wit it but I dnt want my engine to grenade. Is it possible to tune ur ms3 wit atr to 300 hp wit mods Mscai air str8 ner, tbe by yorself following instructions that cn b found online?

 

[RC08MS3]

So it's risk changing the values. I kinda wanna play around wit it but I dnt want my engine to grenade. Is it possible to tune ur ms3 wit atr to 300 hp wit mods Mscai air str8 ner, tbe by yorself following instructions that cn b found online?

anything is possible if your good enough

 

[Mid_Life_Crisis]

So it's risk changing the values. I kinda wanna play around wit it but I dnt want my engine to grenade. Is it possible to tune ur ms3 wit atr to 300 hp wit mods Mscai air str8 ner, tbe by yorself following instructions that cn b found online?

The key if you are not sure of what you are doing is to be patient. Make small changes one weekend, drive all week and see what you have on the following weekend. If the results are encouraging, make more changes. You`re (hopefully) going to have this car a long time: spending a few weeks learning what you are doing and getting it right is not much time in the grand scheme of things. By proper tuning you will get a smoother, more responsive vehicle that is even more of a joy to drive. You`ll broaden the power curve and, yes, increase peak power, but the general consensus seems to be that Mazda did not build a lot of extra room for power gains into this car. I would focus first on getting the MAF table squared away then work on getting consistent A/f ratios and minimal knock readings. Once you have a good baseline to work from, push the boost up a little (a little!) and see what it does to your logs. Smooth things out again then repeat the process. You aren`t paying some tuner obscene amounts of money per session for this: all you`re investing is your own time, so take plenty of it. In this case, slow and steady not only wins the race, it keeps your motor in one piece.

Edit: The "general consensus" as of now appears to have been proven wrong. Careful part selection and tuning is producing some very powerful streetable engines.