Forced induction is not necessarily a high rpm occurance!
Most engines that make more power with a turbo aren't raising the redline in order to do it. They are just cramming more air and fuel into the cylinders at the stock rpm range. The turbo is better suited for this type of upgrade. High rpms require a whole manner of improved components, valve springs, retainers, rods, etc. and is generally used to increase the power on a naturally aspirated engine.
For you nay sayers, that isn't to say that people don't build high rpm turbocharged engines! Those people are usually building race cars and aren't really the subject here.
Former owner of '99 CSVT - Silver #222/2760
356/334 wHP/TQ at 10psi on pump gas!
See My Mods
'05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red
'06 Mazda5 Touring, 5spd,MTX, Black