1/4 mile time

hey wuts up everyone, i went to the track for the first time this year with my 2001 3.4 v6 grand am. all i have is a flowmaster and a K and N drop in filter and my lowest time was a 15.4. everyone at the track was tellin me they were impressed wit that time from a 3.4 grand am. does anyone else have 1/4 mile times that i can compare to because the way these people were talkin it sounded like my GA was faster than others. i dunno wat do u guys think.