My car had Flowmaster 40 series on when I bought it. The noise that came out of them was horrible. Noise, not a deep, throaty, powerfull sound, just loud noise. My wife didn't want to ride in the car as she thought It seemed like we were just trying to get attention with the loud mufflers. I asked around and everyone had a different opinion. Then I read Jim Hand's book. He did extensive testing with quite a few mufflers. Decibels at different rpm, back pressure at different rpm, and how they performed on the drag strip. He compared them all to open headers. Man that guy's dedicated. The results were surprizing. Some of the loudest mufflers only flowed just over half of the open headers and some of the quiet ones flowed nearly as well as the open headers. As the exhaust system was already made up for 14" mufflers I chose 14" Magnaflow. They flow well and are a great deal quieter than the Flowmasters. Not only quieter but they just sound better. My FB buddy put DynoMax Ultra Flow on his and they sound great and not as loud as his old ones were. You almost need a bunch of mufflers with a quick connect system, so you could test drive them all. Hope that helps some.
