Making more hp then rated by a tune?

[ToXicXxX]

So I am currently running a C2 stage 5 tune that is rated for 280hp to the wheels. I just finished a motor build and break in, if I were to crank my boost to 25-27 pounds on my 2871R .64 for a dyno run would it actually be producing appropriate power? I know the stock C2 tune tried to push 27PSI down my N75 before I put a MBC in. I am also dropping in a new 300l/hr fuel pump running 70psi with 550cc injectors. Im looking to pull 400.

I don't need to to pull 400 daily, it's more a proof of concept.

[a4audi4fun]

In theory more boost should provide more powet but there is a breathability and combustion limit. I don't have the exact formula info, (I'm sure the tuners do) but you have to keep within bounds on the fuel/air ratio independent of boost. Also the higher the boost, the more air that has to exhausted after each firing cycle so High Perf tuning is all about maintaining a smooth balance between air/fuel in and exhaust gas out.