Over here in NC we have a hobby shop for military people, i did my custom exhaust, 2.25 piping without the resonator, it was loudas fuck but when i stepped on the gas as loud whizzing/buzzing sound would be heard. So i went back to the shop and put an SI resonator and it sound 100 % better imo, but the noise level went down but it still has a great sound to it.
if u have anymore questions, holla back!