Precision Turbo and Engine BigStuff3 GEN3 PRO SEFI System Hardware & BigComm Software - Manual (Page 89)

BigStuff3 Pro SEFI System
Version 2.1 – February 2011 82
49. Power Valve Fuel (F10 – “Quick Key”)
The first table is Power Valve Fuel. It is used to determine the percent fuel correction, either positive
or negative, for a change in manifold pressure (dMAPdt). The ECU calculates the change in manifold
pressure every 52 milliseconds (ms) as long as the throttle is moving. The ECU will increase or
decrease the base pulse width relative to the dMAP Correction table’s % correction value (i.e. 100%).
Changes in MAP need to be compensated for by increasing or decreasing fuel synchronously to the
base fuel pulse width. Each cell in the input table represents eight (8) kPa increments.
While the engine is running, a “real-time Ellipse” will move within the Power Valve Fuel table
relative to the current % Correction “operating point”!! Use it as a point of reference to help calibrate
the Power Valve Fuel table.
To change a value in the Power Valve Fuel table, move the cursor using the PC’s mouse or arrow
keys to the cell to be changed. Input the desired value and hit
“Enter”
to save the change.
50. dMAP RPM Modifier (F10 – “Quick Key”)
The second table used to calibrate the MAP Transient Fuel is the dMAP RPM Modifier table. Inputs
to the table are used to increase or decrease the dMAP correction as a function of engine RPM. The
positive or negative value inputted into the table is the percent (%) applied to the dMAP Correction
table relative to the RPM (see below).
While the engine is running, a “real-time Ellipse” will move within the dMAP RPM Modifier table
relative to the current RPM “operating point”. Use it as a point of reference to help calibrate the
dMAP RPM Modifier table.
To change a value in the dMAP RPM Modifier table, move the cursor using the PC’s mouse or arrow
keys to the cell to be changed. Input the desired value and hit
“Enter”
to save the change.