1.5L/90ci Blower On A Slant
20psi out of a 1.5L? can it be done?
I'm not saying it can't but, as mentioned above, boost is a function of restriction. If you're pushing an M90 head unit into a stock 225, very likely, but it'll heat up the air quite a bit and you might actually hurt the power capability.
As soon as you up the duration and lift on the cam, or port the heads, uncork the exhaust, or some combo thereof, it alters the efficiency of breathing of the engine, and can actually drop the read boost pressure, despite the fact that its pushing the same amount of air...
Fwiw, good D/A, pullied up M112s can push 18-20 on stock 4.6 Cobras, but it's really pushing the limits on the blower itself, so an M90 or equivalent probably can push that on a 225