[Crumpp]

it is a function of density altitude

Correct

I'm glad to be corrected on this, preferably in layman's terms without underlined scans

It would be nice if people would not stick to their guns when they are wrong so that such things are not required.

My thinking is that supercharger keeps constant pressure up to the FTH and the mass flow through the engine and power is at maximum at FTH. Below FTH intake air is warmer and hence density at the intake manifolds is lower at given pressure and mass flow and power lower than at FTH, above FTH supercharger can't keep the pressure which reduce mass flow and power.

Let's assume that pressure altitude is keeped constant but temperature is higher. Then the mass flow through engine is reduced due to lower density and less mass flow is needed through supercharger to keep constant pressure due to same reason. The power is, of course, lower at this situtation, however, pressure ratio between manifolds and outside is still unchanged and hence the FTH unchanged as well.

Unfortunately, that is not the case and people continue to argue their point.