Read the autocross help page in my sig.

But in most cases hp means nothing at an autocross. I've been autocrossing for years and learned to put my foot in my mouth on several occassions I have a friend with a Fiat that has like 80hp than can run circles around cars with 4-5x more hp.

You'll learn that autocross is more driver skill than anything else. The more seat time you get the better you will be become. At most events I will try to get in 8-15 runs before I pack up and head home. When I was a newbie I asked for rides in other people's cars, had instructors ride in my car, and just car whored (as we say in our group).

And plus swaps and turbos will just throw you into harder more competitive classes where money is no object. Guys who won Nationals in SM (Street Mod) spent around $20-30K on their 2002 WRX! Now that's crazy!

But on a lighter note I know the guy who won STS (Street Touring Street Tires - same class as me) last year and he only spent $5000 on his 1989 Civic Si and killed the rest of the class by about 1.5 seconds on day one. THAT'S ALOT OF TIME!