I talked to a guy who bought some 3" Super Turbos are few years back and he said he had the option to choose between 3" all the way through OR smaller internal pipes. He said back then they could be had both ways. Don't know if that is still true? I bet the 2 1/4" mufflers are 2 1/4" all the way through but who knows.

I drove my car around a few hours today. Its louder but not bad at all and no drone. One thing for sure, it idles better with the Ultra Flos. My cam has a 108 Lobe Separation Angle so I guess the exhaust gets out of the engine a little easier compared to the Super Turbos. But no doubt about it the idle is better.