Homemade dumps.... sorta

Yes, dumps are louder, but it's the internal resonance that can make or break your decision to install them.

Internal resonance can best be described like a drum for example; the sound generated from the muffler has no way of escaping into the open, therefore it bounces back up inside the car, creating vibrations and gives the car a much lower tone. There is also speculation that it may increase throttle response by a hair.