Originally Posted by vxrcymru
I think what the Stage 5 lacks is an increase in torque over where you are now if you are sticking with a standard engine.
Originally Posted by Johnny G
Upgraded rods only ~ 800bhp and 700lb/ft
So on 4.5 and modified turbos you are boost / torque limited in the mid range compared to stage 5.
Stage 5 with upgraded turbos can go for a bit more boost to provide an additional 70/80 ftlbs mid range torque over 4.5.
BHP is +50 higher up the revs on Stage 5 when torque may not be quite such a limiting factor.