hi im about to do a ls turbo in my car and i was wonder if the size of the outlet matter for turbo? the inlet is gonna be 2.5 for sure. its either gonna be a fireball which has a 3.5 outlet or a n1 which has a 4.5 tx

 

If you're referring to the exhaust tip size; as long as it's at least the same size as the inlet and inner diameter of the muffler, the tip size won't matter.