C'mon, man, at least make an EFFORT to search these forums before asking a question like that. That's probably the most common, and generic question asked here and there are TONS of ideas and answers to make extra power. If you look around for like 5 minutes, you'll find more mod ideas than you can afford, but don't expect a free ride if you won't take the time to search before asking someone else to do it for you...

 

The easiest and cheapest thing would probably have to be some sort of air intake, but like Rallysportz said, you'll find tons of info on that in these and other forums.