I had to swap my cats back in a week ago. While I was at it, I decided to take some sound pressure level (SPL) measurements. The test pipes I'm using were purchased from Ricambi. I'm pretty sure they're Hyperflows. Stock cats, stock muffler. Measured 1m behind the car 94 db at start up 98 db when the motor warms up enough for the fans to kick on Hyper flow test pipes and stock muffler. Measured 1m behind the car 94db at start up 104 db when the motor warms up enough for the fans to kick on I was surprised that the initial number was the same. Didn't have an assistant around to explore other RPMs. I'm going to attempt a write up on the install. Here's one of the photos showing the O2 sensor. Image Unavailable, Please Login
Damn - my rock band plays at 100 db!! At IDLE, your F355 is as loud as my band?? I guess we better turn it up!!
I, too, noticed a definate increase in the sound pressure level with the bypass pipes. While the sound was nice, I much prefer the milder sound pressure levels with the cats in the car.
FullChat, funny you mention your band. The reason I have the SPL meter is that a few years ago I was trying to get each instrument in my band down under 95db. (not playing now) I was surprised that the stock exhaust is so loud on the 355.
