[GT40FIED]

Turbo plain and simple. Like Von said, there are some drawbacks, but overall it's the best way to go about making power. Blowers all have parasitic drag (the bigger the blower, the more power they suck up...some race blowers as much as 100hp) and with centrifugal blowers boost is relative to rpm so you need to rev the shit out of the motor to get advertised maximum boost. Roots blowers are better...but there's still the issue of drag and one of air inlet temps. This can be cured with intercooling, but it's a lot harder to package an IC with a roots blower. Nitrous is just...well...no. You have to keep such a close eye on your engine's state of tune and if you use the juice enough, the cost can quickly approach that of a good blower/turbo kit when you factor in refills. The fact is that too many people just don't know how to use nitrous and end up doing severe damage to their motors. Besides, it's only good for short bursts...turbos and blowers are always there and a hell of a lot easier to adjust than a nitrous kit.