1psi= 10hp? Dont think this is too accurate. Options

[KOU In3]

Makes complete sense. You have to remember that psi is essentially just a measure of backpressure in the intake manifold. It's not measuring the actual quantity of air entering the engine (cfm).

So you have two factors.

1) Bigger turbo pushes more cfm per psi. More air being more hp.

2) Efficiency range. Put that turbo from say 65% to 71% efficiency while turning up the boost simultaneously and you'll have the even bigger gains. 65% efficiency of 15psi compared to 71% efficiency of 22psi is going to be HUGE.

Basicly you'll be getting more real work out of the turbo (closer to 100% efficiency) while simultaneously flowing more air per psi with that big 20G than the comparitively wimpy little 14B.

Heck, the more modded you are in terms of a less restrictive engine (better volumetric efficiency) with improved exhaust and intake paths even, the more power you should be able to make per 1psi increase.

As the engine can evacuate the spent gasses and take in more air with sheet metal intakes, better cams, and generally improved breathing, the less the compressed air should be able to 'stack up' in the intake manifold. This should give a lower 'psi' reading on the boost gauge but more real air passing through the engine.