Dimi wrote: ↑11 Oct 2017, 13:33
But i think its strange to be a part of the main wiring on a test engine and even more to do compustion analysis during a race.
Teams have all been running onboard cylinder pressure analysis since 2014. The ECU counts knock events and manages ignition timing (and probably other parameters but timing is surely N°1) on each cylinder individually throughout the race to stay as close as possible to knock without knock.
In quali mode, teams allow themselves to take 4-5 knock events per lap and per cylinder for those running Aluminium pistons, and more like 15-20 (my guesstimate) for those running steel pistons. Ideally, they will endure these knock events at the beginning of the longest straights (when extra torque brings you the most lap time) and turn down the timing to save the engine further down the straight.
Generally, the ECU learns throughout the free practice how to deploy-harvest electric power as we know, but also where the engine is more prone to knock and where the engine will accept a little more timing without knock.
They also count knock events throughout the lifetime of the engine to judge how close it is to a rapid unscheduled disassembly.