any ideas

ok this guy has a 89 5.0 ....saleen by the way and hes got trickflwo heads procharger, stock intake, 150 nitrous, long tubes and a x pipe with no mufflers. my Q is that when he gets into i mean this thing actulyl sounds liek its scream like a 140 db. and i was wondering what it is that makes it do that. i have never heard anything liek that. is it taht he has a blowe cam or what?
 
How is this a technical question?:shrug:

Lemme get this straight:
You stood right next to the car and heard it for yourself then turn around and type your perception of what it sounded like on a forum where we're unable to hear it so that we could tell you what causes it??????

I'm either in a really bad mood this morning (and I don't feel like I am) or someone has opened up the Lame Thread Flood Gates this morning.