carb? or fuel injection? id have to say either way no mash it and go...... if its efi the ecu knows what to do
if its carb there are boosters and crap that take care of that sorta thing....
go get a car at a sales lot and take it for a test drive ... drive until it is warmed up, and approx 10 minutes more to allow all bearings and such to be properly warmed
allow him to drive it and try and find a way to know it isnt just tricking you into feeling something your not.....
ok now drive for approx 10 more minutes and just floor it.... it was faster then right
if that doesnt prove it somebody give this guy a dyno.....