Running 450bhp a newage STI will generally produce more torque than when its running 350
but it will not make as much torque as 2.1 at the same boost or a 2.35 / 2.5 etc etc they seem to make around 400/410 at 450 from looking at the majority of dyno charts.
There are plenty of UK 2.0 STI newages running circa 450 and quite a few JDM ones too,
There are 1 or 2 nutters pushing past 500 on standard internals.