vristang - Doesn't the computer do the 'calibration'? Ford doesn't actually calibrate their meters to the injector, right?
When a component is 'calibrated' 2 things need to be dialed in.
The sensor output
The ecu Transfer
This applies to the ACT, ECT, MAP/BAP, MAF, etc.
The output scaling of the sensor must be known.
When Ford calibrates a MAF meter, it is done on a 'flowbench'
The meter has a specific amount of air sent through it, then the output of the sensor is modified.
Then they move on to another airflow level, and check the sensor output there.
This verifies that the MAF meter output is KNOWN for specific amounts of airflow.
Then the ecu needs to needs to know what the output of the meter is going to be.
There are separate settings in the ecu for the injector size.
A Ford MAF is only calibrated for use with a specific ecu.
Injector calibrations only exist in the Aftermarket MAF world.
Another way to look at it...
The MAF reads airflow and outputs voltage. It is basically translating from the language of airflow, to the language of volatge.
Then the ecu recieves the voltage language, and translates that back into airflow.
There are 2 translation steps there.
If the 2 translations are not EXACTLY the same, then 'miscommunications' will arise.
This is a Calibration in the truest sense of the word.
What the aftermarket does to compensate for Injector size is more of a 'Scaling'
vristang - I know you know these things.
So what if you had a 150mm MAF and a stock MAF with a calibration of 19lb injectors.
Would there be any kind of con with the huge MAF at all to to ECU?
This is a VERY good question.
I have yet to fully explore the affects of this.
Here is what I suspect I will find when I do...
The MAF meter tells the ecu 2 main things. How much air is flowing (duh...), and how hard the motor is working (LOAD).
The engine Load can be thought of as 'driver demand', as it is influenced by throttle position. Or think of Load as a precentage of possible airflow for a given CID and RPM.
Load is where the ecu MAY get confused with larger meters.
Load is used when fine tuning the Ignition Timing and Fuel Injector Pulsewidth.
In theory, both of these things can be corrected pretty easily.
Reset Base timing with a large MAF
The Adaptive Strategy will help dial in the AFR.
How much of an impact will this have, if any?
I have no idea...
To explore this, we would need to look at all the Load tables in the ecu, and make note of how error in Load would affect the output of the tables.
I just haven't gotten around to it...
jason