Fw: MAP vs MAF FAQ

["Bruce Plecan" <nacelp@bright.net>]

Again this is GM specific


 MAF vs  MAP
which is better?.

Well, alot of that is personal opinion.  What can be said are the advantages
and disadvantages of both systems

 MAF advantages
Can be easier to work with.
May have a slight MPG edge
More forgiving to minor engine changes
Full time barometic compensation
Slight edge in open loop emissions


 MAF disadvantages
Application can exceed the air flow measuring of the MAF sensor.
The actual restriction of the metering unit
Plumbing for the sensor
Trying for a turbulent free intake tract.
Lag time for the hot wire / foil sensor to stabilise.
Has to be slightly rich in transistions
Sensor price
Reversion can upset readings

MAP advantages
Sensor cost
easy to learn
Ease of plumbing
Enrichments can to some degree be tied to actual engine demand.
Slight edge in responsiveness.
Inversion not a serious problem


MAP disadvantages
No full time baro compensation
C-3s are lacking in VE Table resolution

Common Problems to both systems
Misplaced IAT, and MATs,  they need to be closer to the intake valve
No timing for MAT correction
Sensors used for MAT IAT slower then molasses to respond to temp change.

Grumpy


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