Megasquirt Field Dictionary

There are 2 types of fields in BigStuff Log Viewer.

Logged Fields - Fields logged by the tuning software. These are defined by the tuning software or tuning software configuration files. MegaLogViewer reads these and and displays values and graphs based on them. If you add additional fields they will automatically be displayed. Even though MegaLogViewer has no control over the naming of these fields, the Megasquirt community has settled on some standard field names. The definitions used here will represent the accepted name used by most MegaSquirt firmware versions. With the variance of firmwares, this list can only focus on the generally available and can not be insured by MegaLogViewer.
Calculated Fields - Fields defined and calculated by MegaLogViewer. These fields are calculated from Logged Fields using formulas defined within MegaLogViewer. They are typically optional fields and only active if enabled from the Calculated Fields menu

Logged Fields:
For a list of logged fields, check online at:
Log Field Dictionary

Calculated Fields:

Boost(psi) - Converts MAP to psi with 0 = to atmospheric pressure.
- Input: "Engine off MAP pressure in KPA" - The MAP value while the engine is not running, corrects for sea level and error.

VAC(inHg) - Converts MAP to vacuum in inHg
- Input: "Engine off MAP pressure in KPA" - The MAP value while the engine is not running, corrects for sea level and error.

Boost-Vac - Below atmospheric pressure Vacuum in inHg, above Boost in PSI
- Input: "Engine off MAP pressure in KPA" - The MAP value while the engine is not running, corrects for sea level and error.

TP ADC - Calculates the original ADC value based on TP in percentage.
     - Inputs:
     - "Maximum TPS ADC" - the ADC value with your throttle at wide open.
     - "Minimum TPS ADC" - the ADC value with your throttle in idle position

MPH\ Xxx\ Gear
     - Inputs:
     - "Tire Diameter(in.)" - Drive tire outside diameter in inches
     - "Final Drive Ratio" - Axle drive ratio
     - "Transmission gear ratio" - ratio for the transmission gear used

HP - Horsepower calculated from rate of speed change. Car must be in the defined gear on level ground for accurate results. Currently uses US measurement units only.
     - Inputs:
     - "Min TP to calculate for" - Filter condition, HP will only be calculated when TP is over this value. This heavy calculation will slow log load times if hp is calculated for the entire file.
     - "Tire Diameter(in.)" - Drive tire outside diameter in centimeters
     - "Final Drive Ratio" - Axle drive ratio
     - "Transmission gear ratio" - ratio for the transmission gear used
     - "Converter stall speed (0 for manual trans)" - Converter flash stall, the RPM that you flash to from a stop with traction.

Fuel Flow - Total Fuel flow for combined injectors in lb/hr or cc/min depending on what rating is used for the injector input.
     - Inputs:
    - "Injector Opening Time" - the injector open time configured in you MS, usually 1.0
    - "Injector Squirts Per 720 crank degrees" - The number of pulsewidth per each 720 degrees of crank rotation. On a sequential engine this would normally be 1. A batch fire can be 1.0 or 0.5 if you are configured to fire all injectors on every crank rotation.
     - "Number of Squirts" - Number of squirts per cycle configured in your MS
     - "Number of Cylinders/Injectors" - Number of injectors.

Instant MPG - point in time fuel economy in Miles per gallon. Like the instant MPG gauge in many modern cars.
     - Inputs:
     - "Injector Opening Time" - the injector open time configured in you MS, usually 1.0
    - "Injector Squirts Per 720 crank degrees" - The number of pulsewidth per each 720 degrees of crank rotation. On a sequential engine this would normally be 1. A batch fire can be 1.0 or 0.5 if you are configured to fire all injectors on every crank rotation.
     - "Injector Size" - the rated or corrected rating for your injector
     - "Number of Cylinders/Injectors" - Number of injectors.
     - "Tire Diameter(in.)" - Drive tire outside diameter in inches
     - "Final Drive Ratio" - Axle drive ratio
     - "Transmission gear ratio" - ratio for the transmission gear used, for Instant MPG usually your high gear. 1.0 in non overdrive transmission, less if overdrive equipped.
Custom - You can create any custom calculated field you would like under the Calculated field menu. Check Formulas for more information.