I'm surpised with all the hating on Flowmasters, Does anyone really think you can add tons of the HP with a simple catback? please all of these catback that we install are only for sound and looks. I said this a dozen time GM has spent tons of money researching and creating the best performance/fuel economy combo do you really think a $400+ exhuast system is going to out smart a room full of engineers? just my $.02
I don't think we're debating the quality or performance of Flowmasters vs. other cat-backs. Obviously, one cat-back compared to the other may show slight improvements, but nothing significant enough to affect a daily driven, 5,500 lb truck...
I just think the sound of Flowmasters is completely nasty....and not to speak for everyone else, but I believe that's what they were referring to, as well. I had Flows on my '69 Mustang and hated them so I replaced with Dynomax turbo mufflers and couldn't be happier. I have a friend with Flows on his '04 Tahoe and it sounds terrible. Loud--yes, "good"--hell no. I don't want to be the obnoxious redneck that annoys all the neighbors...I want to have a truck that will sound good and get attention if I stomp on it, but has great manners when I drive like a grandma...