Absolute pressure vs bmep

[gnalan]

I've read that most high performance naturally aspirated engines seldom exceed 15 bars of break mean effective pressure, but what is the safest absolute pressure at TDC on pump gas before and after the spark plug ignites the air/fuel mixture? I know temperature plays a bigger role in whether or not there will be any pre-ignition/detonation than pressure itself will, but what are the absolute limits for pump gas? I know the absolute pressure is limited by the engine itself, and how well the engine is built to withstand the higher pressures, but engine strength aside what is safe for pump gas without having to pull timing or do something else to compensate for the added pressure?

Same question with using forced induction. What are the safe limits when using pump gas? Are the absolute pressure limits the same?