Discussion and questions related to the course MoTeC M1 Software Tutorial
I am attempting to fill out the inlet manifold pressure estimate table using both throttle percentage and rpm as axes. Instead of the resulting value being expressed in kPA, however, it is expressed as a percentage (0-100). I cannot seem to change this to kPA in the properties window. What is the percentage that the table uses? Percentage of maximum kPA as used in the efficiency table? This seems like a glitch in the software: Throttle position clearly should be a percentage, and RPM as an absolute value, but so, too, should kPA be an absolute value. What am I missing?
Having a percentage value for that table is correct, as it is an estimate of how full the manifold is, in comparison to the reference pressure that you have used when setting up the Inlet Manifold Pressure Estimate Mode. If you have used Ambient, then it is the percentage of the Ambient Pressure that is being used. As an example, if we have a Ambient Pressure of 101.325kPa, and the Inlet Manifold Pressure Estimate Table has a value for the load cell that you are in of 44%, then the calculated value will be 101.325 * 0.44 = 44.583kPa, however, if your Ambient drops to 95kPa as you have driven up a mountain, then the calculated value will be 95 * 0.44 = 41.8kPa.
If you use 100kPa Relative for the Mode, then the calculated value will always be calculated against 100kPa, so a value of 44 in the table will always be 44kPa, with no adjustment for changes in Ambient conditions. If you are using a ITB engine, with no Manifold Pressure Sensor, then this is the recommended mode to use, if you have an AIrbox or Ambient Pressure sensor, then use Ambient Pressure Relative to get a better result.