The MAF works by keeping a small heating element at a constant temperature. The more air flowing, the more voltage is needed to keep it hot and it's also dependant on air temperature too...lots of cold air needs high voltage and idling with warm air needs low voltage.
no get the new greddy e-manage and you don't need a maf at all.
Airflow Output Map - Previously labeled “Airflow Adjustment Map” is now “Airflow Output Map”. This can now used to eliminate the factory airflow meter. This is done by directly inputting voltage or frequency in to this map.
Coolant Temp Correction Map (Must be Selected with Knock Signal 1) - When the ECU Coolant Temp Calibration does not match the e-manage’s tuning, this map is used to tune the system at various temperature ranges.
Intake Air Temp Correction Map (Must be Selected with Knock Signal 2) - When the ECU Intake Air Temp Calibration does not match the e-manage’s tuning, this map is used to tune the system at various temperature ranges. This map is also be used when eliminating the airflow
Mark is right, you would need a MAP if you were to get rid of your MAF. And I also concur with Justin, unless you're pushing some higher turbo numbers (i'd say 300hp) the MAP setup is more work than it's worth. It requires a lot of time and customizing. As Mike mentioned, this chunk of dyno time can go anywhere from an absolute minimum (and this is like if you hit everything dead on) 3-4 hours, all the way up to 1.5-2 weeks.
But a MAP sensor is definately a lot healthier/convenient.