Reply to "SUPERCHARGED EFI"

the Epec manual has a MAF transfer function. Do I read this correctly that I can change the voltage values? I.E.; read the 2 MAFs and double or halve the amount as needed to get the voltage to read 1-5 volts, for both MAFs ?
MAF Transfer Function
The Mass Air Flow (MAF) sensor measures amount of air entering the engine. The base fuel amount
(Idle/Part/WOT Air/Fuel ratio) is based on the readings from the MAF sensor. The EPEC Strategy uses
the MAF Transfer Function to correlate the voltage read from the MAF Sensor to the actual engine
airflow. The MAF sensor is a hot wire anemometer. The EPEC module is compatible with the Ford type
MAF sensors.
The MAF sensor is first converted to a voltage “MAF Volts”. This voltage value is then used as the
input or “X” value to the MAF Transfer Function. The output or “Y” of the MAF Transfer Function is the
air mass that corresponds to the input voltage. Figure 101: MAF Sensor Strategy Block Diagram shows
the block diagram from the MAF Sensor to the actual Air Mass value.
VERY IMPORTANT: The base fuel flow is based on the airflow into the engine. This airflow is determined
by the MAF Transfer Function. If this function is not configured correctly, the Air/Fuel values in the
Idle/Part/WOT fuel functions will give incorrect results.
Type in a new value
and use the arrow keys
to change cells
Currentlly selected
cell is highlighted
by an outline box
Click on "Help" to
get help on
current window
Use "TAB" key to
move to different
objects within the
window
Click on "Close" to
"Undo" changes
and close window
Click on "Undo" to
restore changes to
original values
Click on "Accept"
to record changes
and save to the
EPEC module
Changes shown
as red dashed line
Current values
shown as blue
solid line
Figure 100: ECT Sensor Transfer Function
Extreme Performance Engine Control EPEC Control Strategy
Page 109 of 188
To change the MAF Transfer Function, click on the “Edit” menu and then the “Input/Output
Configuration” sub-menu. Click on the “MAF Transfer Function” menu item. The MAF Transfer Function
will then appear. See Figure 102: MAF Transfer Function Menu.
Click on the cell you want to modify and type a new value, and then move out of that cell using the
arrow keys. See Figure 103: MAF Sensor Transfer Function. Note the original curve is shown in a blue
solid line and the new curve is displayed in a red dashed line. This indicates how much you are
changing the calibration from it original value. At this point you can click on “Accept”, “Undo” or
“Close”. “Accept” will accept the new values and the red dashed line will disappear. “Undo” will undo
the changes and restore the original settings shown on the blue solid line. “Close” will “Undo” and
close the window.
IMPORTANT: If the EPEC module is attached to the computer and you click on “ACCEPT”, the new
values WILL BE written to the EPEC module.
MAF Transfer Function
MAF Sensor MAF Volts Air Mass
Figure 101: MAF Sensor Strategy Block Diagram
An arrow indicates
another level of submenus
exist
Window Title Bar
Main Menu Bar
"Input/Output Configuration"
sub-menu
Main "Edit" Menu
Figure 102: MAF Transfer Function Menu
Extreme Performance Engine Control EPEC Control Strategy .this is a link to the manual.page 108-9
http://www.mustangworks.com/index.cfm/page_id/9