>>2012734If I understood the problem correctly, what limits the power output of each combustion is how much air you can feed into the pistons and the composition of the air (in percent of oxygen, nitrogen, CO2, ...).
Turbos and superchargers use the energy in the exhaust gasses to squeeze more air into the pistons so there is more mass of gasses to expand and more oxygen to react with the fuel.
But you can also change how much oxygen enters the fuel-air mix directly using membranes and filters, and this seems to have the same effect as a turbo.
And it seems that what really limits the amount of air entering the piston is how shitty the valves and air intake system really is. It seems that other valve systems can do a better job and output more power but they were never properly researched and engineered (for example spherical valves or rotary valves).