What the table does
This table adjusts ignition timing based on coolant temperature. Positive numbers advance timing by that many degrees; negative numbers retard it. It's enabled by default, and it can be mapped up to 3D, so most tuners set it against engine load as well as temperature.
Why you'd use it
- Cold engine: a cold engine often runs better with a little extra advance while warming up, because the charge burns more slowly.
- Hot engine: a hot engine is more prone to knock, so pulling timing at high temperature, especially at high load, adds a safety margin.
Using load as the second axis is what makes the table useful. You can pull timing when the engine is hot and working hard, and leave light-load cruising alone.
Our approach
Tune your main ignition table with the engine at normal operating temperature, so this correction reads zero in that range. Then make small changes at the extremes and check logs, especially knock, before adding more. Your coolant temp sensor needs to be calibrated correctly for any of this to work.
Related tables: air temperature ignition correction, gear correction and the ignition corrections overview.
