What do you mean it felt slowish? It should feel a hell of a lot faster than your previous car. There must be something wrong with the car even if there was 4 people in it. It still has a bov and intake, which it probably isn't tuned for. If any of your friends own an sti get one of them to go with you. They should know how it should drive. Also stock boost should be around 14 lbs of boost.