Ignition Main Tables

The Ignition Tables are the primary ignition calibration used by the ECU and define the base ignition timing as a function of engine speed and load.

The table values represent the desired ignition timing in degrees Before Top Dead Centre (BTDC) and are typically indexed by Engine Speed (RPM) and Engine Load.

The ECU uses the active Ignition Table as the starting point for all ignition calculations before applying additional ignition corrections, compensations, torque reduction strategies (Strat Modes) to determine the final commanded ignition timing.

Specifications

  • Units: Degrees BTDC
  • Minimum Value: -100.0 Deg
  • Maximum Value: 100.0 Deg

Function Behaviour../../config/triggers/crank-index-offset-setup.md

  • Higher values command more ignition advance.
  • Lower values command less ignition advance.
  • A value of 0.0 Deg represents no ignition advance before TDC.
  • Negative ignition timing values represent ignition after TDC (ATDC)

The final ignition timing delivered by the ECU may be modified by additional ignition corrections and compensations, including:

  • Global Ignition Trim
  • Coolant Temperature Compensation
  • Intake Air Temperature Compensation
  • Knock Control
  • Idle Ignition Control
  • Ignition Retard Torque Reductions via User Torque Limits and Strat Modes
  • Other configured ignition corrections

⚠️ Important - Ignition Timing Synchronisation

Before calibrating the Ignition Table, the ECU ignition timing must be synchronised with the actual engine crankshaft position.

See the overview below or view : Crank Index Overview for more help.

To verify synchronisation:../../config/triggers/crank-index-offset-setup.md

  1. Enable Ignition Lock and set a fixed ignition timing value (Ignition Lock Angle).
  2. Use a timing light to measure the actual ignition timing at the engine.
  3. Compare the timing light reading with the configured Ignition Lock Angle.
  4. Adjust the Crank Index Offset until the timing light reading matches the Ignition Lock Angle. This test should be completed at idle.
  5. Next, verify the ignition timing as engine speed is increased while adjusting the Ignition Delay Time. Correct Ignition Delay Time calibration ensures the commanded ignition timing accurately matches the actual crankshaft position across the complete engine speed range.

Adjustment guidelines:

  • If the measured ignition timing retards as engine speed increases, increase the Ignition Delay Time value.
  • If the measured ignition timing advances as engine speed increases, decrease the Ignition Delay Time value.

Once synchronised, disable Ignition Lock and the ECU will accurately command the ignition timing values defined by the Ignition Table and associated ignition corrections.

⚠️ Warning

Incorrect ignition synchronisation will result in the ECU commanding ignition timing that does not match the actual engine timing, which can lead to poor engine performance or engine damage.