Think about it on cossie engines.....

Your average 400bhp engine running 30psi+ on a T34 and greys---- 7.3comp
Your average 500bhp engine running same boost as the 400bhp T34 lump, but on a fuckoff T4 and 8 greens--- 7.3comp AGAIN.

Same boost pressure, same comp ratio needed, no matter how big or small the turbo is....