GM ESC modules and matched knock sensors.

[brian617]

One question for the group... knock is when the compression cycle heats the mixture to the point where it ignites before the spark (pre-ignition). How does retarding the spark seek to cure this? I can see how making the mixture richer might cool things. Overall retarding the timing would cool things when knock isn't present. Perhaps someone could explain?

-Tom

Pre-ignition (ignition before spark) and "Knock" Detonation (after ignition) are two different events.