Ah, tourqe is more useful for the overtaking and acceleration out of corners.
The turbo is from a landrover defender diesel as far as I know, hence it passes its barrier at around 5000rpm.
The car will definately be much faster as the area under the graph has increased. Peak power is pub talk, an engine that makes 800bhp at 12,000 revs for 1000revs is no use to anyone, whereas an engien that delivers a steady 170-ish/ft lbs of torque accross the board is the engine that powers the winning cars... thats just my opinion though
Matt