Michael
Welcome to the forum. We are here to help you get aquatinted with your new to you Boxster. My first recommendation for anyone just joining a forum, is to take some time and poke around the forum, you will discover many discussions and answers to your question(s) already exist.
+ The general consensus is our boxsters are producing near their maximum power and the additional gains are minimal compared to the cost (short of dropping in a newer, larger engine).