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MAF Scaling/Resistor Mod spreadsheet/ cheatsheat.

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Old Dec 26, 2014 | 02:03 PM
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From: Bay City Tx
MAF Scaling/Resistor Mod spreadsheet/ cheatsheat.

Merry Christmas guys. Here is a cleaned up version of what I used to get in the ballpark on MAF scaling. It's set up for the stock maf sensor and can be used to change the diameter of the housing as well as add voltage dividers. Every value intended to be changed is in teal and everything else is color coordinated by section.

MAF diameter is non unit because it's ratio driven so you can use inches or mm, resistance values are also non unit for the same reason. There are a lot of unknowns so this is not going to churn out the perfect numbers, but it will get you within some easy calibration of the real values.
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MAF Scaling calc.zip (4.1 KB, 250 views)
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Old Dec 26, 2014 | 04:19 PM
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So this is a spreadsheet for MAF scaling with by only using a voltage divider and no tuning via software? That's awesome! This will be useful for me in the next few weeks as an interim solution to a new diameter!
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Old Dec 26, 2014 | 04:45 PM
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From: Alvarado, Tx
You will still require tuning. This should get you close. I haven't looked at it hard yet.
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Old Dec 26, 2014 | 05:36 PM
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From: Bay City Tx
Yeah this doesn't take the place of tuning, instead it just gives you a better point to start at. The original equation for voltage to maf conversion I made by playing around until I had an exponential equation that fit the line. It just makes it easier when you change the voltage scale in your tables.

Depending on what resistors you use the voltage that the ECU sees might get skewed a bit (in unintended ways). So you may end up guessing at where 5.5g/sec should be on voltage and then end up .2 off in reality and have to slide everything down .2 volts. But it's still better than nothing and after that first calibration it should be close.

Also the further you go out from stock size the more the math will be off from reality. This is because of how air flows in a pipe and the distance of the MAF sensor from the center of the air-stream. Again it should be better than nothing especially if you keep it under 4".
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Old Dec 26, 2014 | 07:03 PM
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Right, I totally see what you guys mean. I reformatted it to be abit more useable (trying to understand what it does, lol).

The "top resistor" represents the resistor going to positive, and the "bottom resistor" represents the one going to ground, correct?
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Old Dec 26, 2014 | 07:27 PM
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Yes, but positive in this case is unaltered signal from the MAF.
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