Kenny Bernstien proved that back in the early 80s. By polishing his top fuel car and NO other mods, he went quicker in the 1320. That's about the time all these polishes started popping up on the market. So, I guess it is to say that a polished turd is a quick turd. But alas......it is still a turd.

 

well i got the gibson duel exhaust at idle and easy accleration it sounds good BUT if you get on it it sounds like a ricer

 

Ahh, I found the comparison I was looking for. This will let you know what performs the best and what doesnt:

2 “ Straight Pipe 283 CFM
2 ¼ “ Straight Pipe 365 CFM
2 ½ “ Straight Pipe 521 CFM

2 ¼” Typical Bent tailpipe 268 CFM
2 ½” Typical Bent Tailpipe 417 CFM

2 ¼” Inlet/Outlet_ Glass Pack Tips- No Louvers- Smooth 274 CFM
2 ¼” Inlet/Outlet- Glass Pack Tips-Louvered 133 CFM
Same as above set for reverse flow 141 CFM
2 ¼” Cherry Bomb 239 CFM
2 ½” Cherry Bomb 294 CFM

2 ½” Inlet/Outlet Dynomax Super Turbo 278 CFM
2 ½” Inlet/Outlet Ultraflow Bullet 512 CFM
2 ½” Inlet/Outlet Gibson Superflow 267 CFM
2 ½” Inlet/Outlet Flowmaster ( 2 Chamber) 249 CFM
2 ½” Inlet Outlet Flowmaster ( 3 Chamber) 229 CFM
2 ¼” Inlet/Outlet Thrush CVX 260 CFM
2 ½” Inlet/Outlet Maremount Cherry Bomb 298 CFM
2 ½” Inlet/Outlet Hooker Aero Chamber 324 CFM
2 ½” Inlet/Outlet Hooker Max Flow 521 CFM
2 ½” Inlet/Outlet Borla Turbo 373 CFM
2 1/2" Inlet/Outlet Magnaflow 284 CFM

 

But what does all this mean? What are the engine/computers requirements? Just because a particular muffler flows a certain amount of CFM on the test stand means little. And it has little bearing on whether it makes it sound like a ricer or not.

And I recall on an SC thread a week or so ago RIPP said that of all the mufflers they DYNO tested (when trying to make the JK perform naturally aspirated) the only one that actually made more useable power was the MBRP.