I agree w/ blury. I still think your friend is a moron and doesn't know as much about cars as he may like to think. Here, look at the red lines and tell me Zetecs aren't supposed to be modded
Oh, and in case he doesn't know what that is, it's a dyno plot. Some of us use those to tune our mods in. It's a different philosophy than taking the highest gain listed by a mod manufacturer and just adding it to your engine's HP and saying "I got 27HP from my intake, therefore my Civic has 98HP now!!!!".
Your friend = import pride ricer