yeah, as tayles said, the 4 cylinders aren't built for power. But the one thing i did with my 6 cylinder was clean the air filter, was SOOOOOO DIRTY, there were leaves in my airbox :S:S:S:S heaps more power afterwards. another thing you can do is increase the intake piping to a larger size. wont do much for porformance but done with other things may help. camrys are heavy, so if theres anything i can do without in the boot or anywhere get rid of it. ummmmm exhausts are meant to help, but i dont know if the 4 cylinder improves much with them. thats about all i can think of atm. with regards to a supercharger, they are quite exxy and theres not much room for a turbo (at least in the V6, may be diff with the 4 banga) hope thats of some help