Originally Posted by M3takesNYC
I trust them I was just looking more for an understanding. I am always the type to want to know "why" and not just accept it is what it is. Although I accept it in this case I am just curious.
RPI for example does the opposite on some of their other exhausts. They make the rear smaller diameter to admittedly keep the exhaust gas velocity up.
Who knows obviously these guys are pro's!
They also have short 90 degree bends into the mufflers.