Open headers are as load as it gets. Straight pipes are loud too. The catalytic convertors will make it slightly quiter.
why not weld a trumpet to your exhaust.? or a good ref's whistle?
straight headers
Straight pipe exhaust meaning no exhaust no resonator only cats or a exhaust with cats ? If so which exhaust ? Went to a muffler shop today and the guy said straight pipe is the loudest it will get. I want to make sure it is or not.
Also the car is a 2007 bmw 525i
