[Ryland]

the spud gun idea is about right, it's about tuning your exhaust, only with your engine you can also get to large aroud, so your exhaust is kind of echoing around in the tube, instead of exiting exhaust gases have momentum and you want an exhaust system that allows that momentum to work with the engine instead of agenest it, if a large pipe was ideal then no pipe would be better, right? try running an engine without any exhaust and it will hardly run.
The only advantage that a glass pack can have is letting you know when you are stepping on the gas to hard, as it will get louder at that point, use a light foot that keeps the vehicle quite and you will quickly learn to avoid noise violation tickets and get better mileage at the same time.