redsoxs7

so i have a 1988 mustang gt auto (ya i know) its pretty much stock except for full mac exhaust bbk pullies makeshift pvc intake and 3.55 gears two years ago at the track i was running consistent 14.9 a year later its running consistent 15.3 15.4 anyone know why there’s such a difference any idea of what maybe needs to be tuned up or cleaned?

hondhunter

did u change tire pressue? is the air hotter or colder?