Using Excel to dial in your maf curve (meth users, perfectionists, etc.)

[dale_gribble]

I ran this on my new Mazda maf sensor (finally got tired of reman inconsistencies). The curve looks beautiful, I can't wait to load it up and take it for a spin.

Just an FYI for any dummies out there like me, when @TiGraySpeed6; provided his excel example and included =J2*I2^K2 where J = base, I = MAF volts from ATR, and K2 = power, this equation has to be entered exactly this way in Excel or the computation is wrong. I was doing I2*J2^K2 and my numbers were wrong (of course because its the base to power).

Use a row of @TiGraySpeed6;'s and/or @rfinkle2;'s data to verify the equation and numbers in your own spreadsheet as a check before running your own data, i.e. run a row of their data in your equation and make sure the numbers match theirs. I did this to figure out what I did wrong.

[dale_gribble]

I'll make a thread about it maybe, but I found the reman had poorer granularity and flat spots in its response through the voltage range. Even on my initial comparisons, the Mazda OEM MAF responds more linearly across its response range and even has better voltage range response given the same airflow. Of course I don't flow any more, but now the sensor responds from 0-4.3v whereas the reman only responded from 0-4.1v in my car. Doesn't sound like much but this gives more granularity in the MAF sensor calibration table and will probably give me a much flatter AFR curve.

[CosmicArkie]

Originally Posted by dale_gribble I'll make a thread about it maybe, but I found the reman had poorer granularity and flat spots in its response through the voltage range. Even on my initial comparisons, the Mazda OEM MAF responds more linearly across its response range and even has better voltage range response given the same airflow. Of course I don't flow any more, but now the sensor responds from 0-4.3v whereas the reman only responded from 0-4.1v in my car. Doesn't sound like much but this gives more granularity in the MAF sensor calibration table and will probably give me a much flatter AFR curve.

.2 is still like about 4.88 percent....

Plenty of error/room to screw things up.

[sidekick]

This should be added to the KB and stickied. @Raider;

[Cobb Tuning]

Originally Posted by rfinkle2 Good question. I know DJ asked David about the maximum amounts of trim allowed and those tables to be exposed, but I haven't heard anything else about it.

Still in the testing/experimental stage to make sure we have all the controls you need before letting it go out.

-David@COBB

[dale_gribble]

This should go without saying, but for any n00bs attempting this, make sure your datalog is free of any KR before attempting this calibration. KR = added fuel = richer AFR = skewed MAF cal curve.

This process assumes a 0 KR datalog as a benchmark so you are calibrating the correct MAF curve.

[dale_gribble]

@rfinkle2;

I decided to try your method to dial in the MAF cal when the car is in CL and using LTFTs for correction. Instead of using the target AFRs for the OL calibration portion as the correction factor for the MAF g/s, I used the LTFTs as the correction factor for the MAF g/s and plotted that against MAF voltage to create the curve.

So, I created a column beside MAF Airflow (g/s) entitled Mass Airflow (g/s) CORRECTED. I multiplied the Mass Airflow (g/s) column by the LTFT % correction to arrive at the Mass Airflow (g/s) CORRECTED number. I ran this calculation through the entire range of closed loop MAF readings.



I then plotted the corrected Airflow (g/s) column against the MAF voltage and came up with a curve.



I applied this curve to the applicable voltage range section of the MAF cal per your guidance, plugged it into ATR and boom, perfect CL maf cal.

[rfinkle2]

Very cool.

[Mistersix]

Wow this makes this process so much easier. I may employ this to tighten my maf cal up.

[ms3blackmica]

Any MSF tuners backed up and have a meth car in need of tuning?

I'm having too much fun with this!

[rfinkle2]

Originally Posted by ms3blackmica Any MSF tuners backed up and have a meth car in need of tuning? I'm having too much fun with this!

I consider you one of our best tuners. (sticking Tigray right in there as well)

Be careful what you wish for!!! LOL.

[BlueStreak]

Damnit, Rob. Just take my keys, my car and my laptop and do your thing.

Don't come back to me until it's done.

[ms3blackmica]

@Raider;

This thread deserves a sticky.

Rob did not have to share his secrets and tricks of which make his tuning skills superior but he does so for benefit of the mazdaspeed community.

[Raider]

I made it a knowledgebase article and is a stickie

[ms3blackmica]

Woohoo!

[Mfinlay04]

Originally Posted by dale_gribble @rfinkle2; I decided to try your method to dial in the MAF cal when the car is in CL and using LTFTs for correction. Instead of using the target AFRs for the OL calibration portion as the correction factor for the MAF g/s, I used the LTFTs as the correction factor for the MAF g/s and plotted that against MAF voltage to create the curve. So, I created a column beside MAF Airflow (g/s) entitled Mass Airflow (g/s) CORRECTED. I multiplied the Mass Airflow (g/s) column by the LTFT % correction to arrive at the Mass Airflow (g/s) CORRECTED number. I ran this calculation through the entire range of closed loop MAF readings. I then plotted the corrected Airflow (g/s) column against the MAF voltage and came up with a curve. I applied this curve to the applicable voltage range section of the MAF cal per your guidance, plugged it into ATR and boom, perfect CL maf cal.

I did this as well but used LTFT +STFT combined to determine my best fit line and used that equation to determine my CL MAF chart. Seems to work pretty well. My LTFT are all -/+ 2 solid work guys as the norm

Sent from my Galaxy Nexus using Tapatalk 2

[Dano]

IMO. STFT is too volatile to be used in this calculation. You can blow on your filter and watch it go up. Lol.

Interested to see how yours holds up over time.


Tappin

[ms3blackmica]

The method that Rob posted in the OP works very very very well for WOT tuning on Gen 1's that are so dependant on the MAF curve being precise.

I finally got a chance to use this method on a friends car.

After the first WOT log, I did all the gymnastics in Excel and adjusted the MAF curve with the values that were produced.

On the next log the car was much closer to target and transitioned from stoich to OL AFR very smoothly. From this point on, all I had to do was add 2% and that was it. Car hits target perfectly.

WOT MAF Curve dialed in after 2 adjustments?

I'll take it.

Thanks again Rob.

[Mistersix]

I cannot get the maf voltages from atr to post vertically in excel. Its making me crazy. I only got one paste>special window and it does nothing. The paste>special>values>transpose window just doesn't exist from me. WTF!!!

[rfinkle2]

Originally Posted by Mistersix I cannot get the maf voltages from atr to post vertically in excel. Its making me crazy. I only got one paste>special window and it does nothing. The paste>special>values>transpose window just doesn't exist from me. WTF!!!

What happens when you right click in an empty cell?

[Mistersix]

In that menu is a paste options menu. when i click paste special i just get the window with (paste as: unicode text, text, csv.)

[TiGraySpeed6]

What version of Excel are you using?

[Mistersix]

excel 2010? Whatever windows seven comes with i guess.

[ms3blackmica]

I can make a video on how to do it if you want @Mistersix;

[Mistersix]

All was smooth up until this mystery menu that everybody else seems to have. Is my version old or something?

Basically i wanted to try this out in anticipation of upgrading to a bigger intake. So i loaded an ots maf cal up and grabbed a log. Unfortunately its only a 3rd gear pull, but its just for practice anyways. The snip below is where i'm at. I've been searching threw the helpfile but it says exactly what you guys already said on the first page. But that box is just not there. Its fucking with me i swear.

[rfinkle2]

Originally Posted by Mistersix excel 2010? Whatever windows seven comes with i guess.

What do you see when you hit control "v" after you copy?

(hold the control button)

[Mistersix]

The voltages i copied from atr paste horizontally in starting in the box i highlighted all the way to the left.

Like that. With respect to the last few. without that special paste function they wont go vertical?
3.05 3.09 3.13 3.16 3.20 3.24 3.28 3.32 3.36 3.40 3.44 3.48 3.52 3.55 3.59 3.63 3.67 3.71 3.75 3.79 3.83 3.87 3.91 3.95 3.98 4.02 4.06 4.10 4.14 4.18 4.22 4.26 4.30 4.34 4.38 4.41 4.45 4.49 4.53 4.57 4.61 4.65 4.69 4.73 4.77 4.80 4.84 4.88 4.92 4.96 5.00

[rfinkle2]

Originally Posted by Mistersix The voltages i copied from atr paste horizontally in starting in the box i highlighted all the way to the left. Like that. With respect to the last few. without that special paste function they wont go vertical. 3.05 3.09 3.13 3.16 3.20 3.24 3.28 3.32 3.36 3.40 3.44 3.48 3.52 3.55 3.59 3.63 3.67 3.71 3.75 3.79 3.83 3.87 3.91 3.95 3.98 4.02 4.06 4.10 4.14 4.18 4.22 4.26 4.30 4.34 4.38 4.41 4.45 4.49 4.53 4.57 4.61 4.65 4.69 4.73 4.77 4.80 4.84 4.88 4.92 4.96 5.00

OK. When you have the copied data on your clipboard, use the command control V and hold control. @ the bottom of the pasted data, you should see a small cilpboard. Hover over the option buttons.

You should be able to find both the value and transpose option buttons.

[TiGraySpeed6]

Go ahead and paste it horizontally in an open area

Then highlight the values and copy again

Select the top cell where you want to paste vertically, and then you can use the right click menu and the transpose button or the paste button drop down on the home menu and choose the transpose button

[Mistersix]

Originally Posted by rfinkle2 OK. When you have the copied data on your clipboard, use the command control V and hold control. @ the bottom of the pasted data, you should see a small cilpboard. Hover over the option buttons. You should be able to find both the value and transpose option buttons.

That little box does indeed pop up after i paste. But all that is in it is a paste icon and (use text import wizard). I messed around with that to no avail.

[rfinkle2]

Originally Posted by Mistersix That little box does indeed pop up after i paste. But all that is in it is a paste icon and (use text import wizard). I messed around with that to no avail.

See Tigray's post above.

Tigray's method > my method.

[Mistersix]

Originally Posted by TiGraySpeed6 Go ahead and paste it horizontally in an open area Then highlight the values and copy again Select the top cell where you want to paste vertically, and then you can use the right click menu and the transpose button or the paste button drop down on the home menu and choose the transpose button

Ahh. Now that worked. But now i got a million values going down, lol.

Time to dole out some thanks.

[Mistersix]

I have twice as many volt cells as the other cells. Guess you really need a 4th gear pull to do this right.

I'll try to get a 4th gear tomorrow and try again. I'm still not clear on what to do beyond this point. I really wanna learn to use this though. As i said about upping to a bigger intake and once summer settles in i plan to go back to the eth as well so i'll need to maf cal for that. And this seems like it beats doing maf cal the old way, point by point.

btw, what does the arrow pointing up mean? =J2*I2^K2

[blackrs99]

Thanks Rob! This is awesome, got my MAF cal perfect now!


@Mistersix, your curve seems to be opposite of what you should see because it's plotting the graph over wrong data, AFRs to be exact. You need to graph the curve against the Maf V reading from the log. You can either delete other columns you no longer need, or copy/paste data in a new book.

[rfinkle2]

Originally Posted by Mistersix I have twice as many volt cells as the other cells. Guess you really need a 4th gear pull to do this right. I'll try to get a 4th gear tomorrow and try again. I'm still not clear on what to do beyond this point. I really wanna learn to use this though. As i said about upping to a bigger intake and once summer settles in i plan to go back to the eth as well so i'll need to maf cal for that. And this seems like it beats doing maf cal the old way, point by point. btw, what does the arrow pointing up mean? =J2*I2^K2

It is a "carrot".. It means "raise to".

In text:

2^2 is said "2 raised to the power of 2" aka "2 squared". Also = 4.

Honestly guys, a very good maf cal can be done by self adjusting the breakpoints, and by using the technique in the helpfile.

This is just one thing that had always bugged me when sending "squiggly" maf curves to people.

As long as the logged values are within a few .10ths of what you are commanding in the fueling tables on your car... this is completely unnecessary.

Mistersix, post all of your questions if you need a hand.

[sidekick]

Here are templates for correcting both CL and OL.

[Mistersix]

Super cool templates. Just not real sure how to get the copied voltage values from atr to equal the number of cells in excel.

[sidekick]

Originally Posted by Mistersix Super cool templates. Just not real sure how to get the copied voltage values from atr to equal the number of cells in excel.

I've just been using the range of MAF voltages I saw in the log. They don't need to line up.

[TiGraySpeed6]

Correct- the logged voltages don't need to match the ATR values. They're only used to get the corrected MAF values, which are then used to feed the chart.

The chart gives you the values to work against the actual ATR MAF Volt values.

[RE-ACTIONENGSPEED3]

I have just tried it,very cool.....