Ignition Gear Correction is a table of timing changes, one per gear. A positive value advances timing by that many degrees in that gear. A negative value retards it. It's disabled by default.
What it needs
The ECU has to know what gear you're in. The table only becomes available once a gear position sensor or a gear calculation is enabled. See gear detection to set that up. If gear detection is unreliable, this correction will be too, so verify it in logs first.
How we use it
- Traction in low gears: pulling some timing in first and second softens the torque hit, so the tires have a chance to hook.
- Knock in high gears: higher gears load the engine for longer, so an engine that's happy in third may knock in fifth. A small negative value in the gear where knock appears is cleaner than lowering the whole base table.
The table supports up to 4D mapping, so gear can be combined with other axes when a single value per gear isn't enough.
Adding timing with a positive correction is still adding timing. Make changes in small steps and confirm with knock monitoring.
For other timing adjustments, see coolant temp and air temp corrections.
