I have a 4dr 2001 cavalier with a 5-speed transmission and a 2.2 liter
engine. I want to know what I can fairly easily do or add to it to get
better performance out of it. Specifically better torque, horsepower
etc. I don't want anything that's extremely obvious without popping
the hood.

Since no one has answered with anything -- nitro kit? Not too
expensive for ?these important short bursts". I won?t tell your
insurance company if you don?t :-)

Best