Dial in timing using det cans and knock sensors to listen for pinking ( pre detonation of air fuel mixtures)
To dial the timing in we use 7maps, ignition maps x2 related to cam positions, 2x ignition correction maps related to temps, and knock control recovery maps.
The higher the peak boost the greater the peak cylinder pressures, and the mixtures burn quicker and easier, so with 25psi peak boost less timing is needed to get a the combustion to force the piston down at just after TDC, if too much timing and the combustion can happen as the piston comes up, which give know and power loss, too little ignition advance and again loss of power and high egts. As the peak cylinder pressure drop along with the boost at the higher rpms we can add timing to compensate for a slower flame front (start of combustion). There is a find balance to getting if right to make the best power stroke, a poor timing map can lose around 25bhp on a turbo engine. On peak boost I am seeing a safe 12deg and at the top end 22deg, with water injection I can see another 4deg on top and still be knock free and gain 10bhp in places.
Correct ignition timing is free
