Guys, I think you pretty much all agree but are failing to get it out in a way you all agree on. I'll have one attempt in laymans terms. Then I'll butt out:
We all know power is a simple function of torque and rpm. Increase either the torque or use-able rev range of an engine and you increase the power output. That makes your car faster. Its that simple.
A nice easy example, is a formula one engine. My lowly NA mustang has more torque than the F1 car!!
The formula one motor, however, revs to 18000 rpm and generates crazy power!