Are cylinder pressure and boost pressure inextricably linked

[ginge191]

Which is why a TD04 at 25psi will be fairly reliable and produce ~160hp with the fuelling to match, and a GT15 at 25psi will be spinning it tits off, producing a very hot charge and only about 130hp.

On this note - in terms of torque and A/R ratios - this is what im primarily trying to understand at the moment.

using your exmaples, would the GT15 have a greater low end torque due to a quicker small time? or would it mean both turbos create the same torque, but through a prolonged period?

What im trying to achieve is the best possible low end torque and through reading, understanding that the larger turbo's have a greater a/r as apposed to smaller turbos creating a larger bhp? but not necessarily a decent low end boost?

clarification or am i getting this confused?
appreciate the patience