Mopar vs Rice

My cousin has a 97' GTP and like all them GTP guys they think their tiny supercharger is the baddest thing to hit the street. Well his car is built, cam, intake, computer crap..bla bla about 5k worth of stuff...well we go out almost every weekend and always find a 2 lane highway and just cruise. Well it always pisses him off when he punches it the motor kicks down to 2nd and pulls were mine i leave it in 4th (grinds a bit when i downshift) and i pull right by him. now hes really scared now that i have put a new intake, carb, and smaller dia. tires on the back......should be fun!!!