Perfect Power Application Notes.


Application Note : AN 12

This note describes the throttle deflection calibration. The same process applies if a TPS (throttle position sensor) or an AMP (absolute manifold pressure) sensor is used as the deflection input.



The XMS4 needs a (horizontal) map deflection input to select map points for injection and ignition. The signal normally comes from a throttle, but other sources can be used, as long as they describe the engine LOAD.



The input must be DC voltage in the range from 0-5 volts. The input draws virtually no current. The throttle (or load) sensor must give a voltage out. If this is not the case, then the device must be excited, as shown in the following diagrams :


XMS4 Stand Alone Unit - TPS Sensor Wiring



XMS4 Stand Alone Unit - AMP Sensor Wiring


It is acceptable, if the output voltage span between idle and full open throttle is 2.5 volts or more. However, the voltage should never exceed 5 volts.




If the TPS percentage starts high and goes low when the acc is pressed then tick the invert TPS in the ShiftF2 map. Put the throttle (load) at idle, and read the indicated throttle percent that is displayed by the software, this is the lower calibration percentage. Then put the throttle at full open, and read the throttle percentage again, this is the high calibration percentage. The values can be applied in a linear or un-linear graph.




It is advisable to reduce the Idle TPS percentage (±1%) so as to always be in the left column.