Precision Turbo and Engine BigStuff3 GEN3 PRO SEFI System Hardware & BigComm Software - Manual (Page 121)

BigStuff3 Pro SEFI System
Version 2.1 – February 2011 113
 Pan Vacuum – The oil pan vacuum or pressure can be logged using a GM 2 Bar MAP, which
will read and record the pan vacuum/pressure in inches of mercury. A negative number
represents vacuum and a positive number represents positive pressure in the crank case.
 Fuel, Oil and Turbo Back Pressure – Using a 1/8” pipe thread, 0 – 150-psi pressure
transducer (available as an option from BigStuff3), the fuel, oil and turbo back pressure can be
independently logged. Logging the fuel the rail pressure is particularly import in boosted
applications where rail pressure needs to increase with boost pressure. The logged fuel
pressure data provides the user important insight into whether the fuel pump(s) is capable of
maintaining a constant fuel pressure differential during critical boost events.
 Transmission Input Shaft Speed (TISS) - The GEN3 ECU can accommodate input wheels
with 1, 2, 4, or 31 teeth. Calculates a 16 bit rpm. This is an optional feature within the DAE
system.
 Transmission Output Shaft Speed (TOSS) – The GEN3 ECU can accommodate input wheels
with 1, 2, 4, or 40 teeth. Calculates a 16 bit rpm.
 Torque Converter Control (TCC) Slip Percent (%) – Calculates the slippage between the
engine and the drive shaft and displays the result as a percentage (%) slip. This is an optional
feature within the DAE system.
80. Calibrating with the Trace Function
The BigComm software includes a very powerful calibration tool called the “Trace Function”. The
“Trace Function” allows the user to calibrate Fuel and Spark Tables, using a Logged data file, “On-
Line” or “Off-Line”.
To use the Trace function, open the Fuel or Spark Table. Once opened, hit the T key on the PC
keyboard and the screen below will open.
The “Choose a Log File Screen” (shown above) will open and display the available, previously logged,
files. Select and open the desired log file. Once opened, the Fuel or Spark table will turn yellow
indicating that the Trace function is enabled. A trace line, representing the logged data file, will
superimpose itself over the fuel or spark table.
Note: Scaled RPM (Scld_RPM) and Scaled Load (Scld_Load) must be logged in order to support the
“Trace” function.