i have tons of cylinder-pressure data etc. for any variations of Lambda / Ignition angle on the dyno and these def. show that there is no benefit in decreasing EGTs as far as 700° or going rich as hell.

Me too.

I see very high peak pressure for lambda 0.85.

It always depends on the engine. You will have high peak pressure with suitable ignition angle and lambda 0.85.

Some engines can take it, some not.

You will have lower peak pressures on lower lambda with same engine and ignition degree, but nearly same average pressure per combustion cycle (= torque).


So everyone is free to choose. i choose lower lambdas, lower temperature and having engine happy long time.