No rattling.

 

I might be the one claiming that: the sound that you will get without changing the oem muffler it's very nice inside the cabin, and I can't see me owning a Cayenne without this pipes. It isn't loud at all, I mean my first gen V8 is much quiter inside the cabin than my friends 957 V6.
But, again the OEM muffler isn't a free flow type, so that at one point you will hear what you can hear on the movie linked below from 1.03 to 1.05 http://www.youtube.com/watch?v=fzWRxdC7lrA, and that's annoing cause if you are closer you will hear it louder and clear, and that's the sound I don't like, or maybe its just me. That's got nothing to with the metalic sounds that are produced when the cats are warming up.
Don't know how it works for the newer ones with the sport option that you get, cause it sound like when sport is on like you dont need for other performance muffler. Don't know so many about this 2nd gen muffler, but the sport mode is acting like a diverter valve, so the sound will be much better. getting a system like that for a 955 is very expensive, but it can be done easilly done by a good exhaust builder in your area.
The sound of the V8 NA is different from the Turbo ones, as you know a turbo engine will not scream that hard if it doesnt has any exhaust at all like a NA does, so this apply for havig the same exhaust on different engine types - NA and Turbo.
Also, having these installed you will see that the car can rev quicker, IMO.
in the end, I strongly advise all of you to use these 2nd cats removal pipes, you will not regret it, and also that sound you'll never hear it from inside of the car, just the nice rumble of the V8.

 

fabspeed claims it will give you 15+hp to the truck. but realistically im thinking anywhere from 10-12hp for the pepper. they also say it will dramatically change the throttle response as well as give you a better mpg. if you goto the group buy thread i posted a sound clip of a gts before and after the bypass pipes, they sound badazz! i will post some links to fabspeed so you can get a detail description and the dyno results associated with the 2ndary bypass pipes for your gts.

http://fabspeed.com/cayenne.html ---description
http://fabspeed.com/DYNOresults/Caye...0Catbypass.jpg ----dyno results

 

What part of TX are you in? I have them on my GTS is you would like to check it out....

 

houston, i would love to check them out 1st hand, if you want to do a 4hr drive down here

 

Texas Cannonball is this weekend??? You could come up!

 

hmm, what is texas cannonball? btw your pepper is looking sweet!

 

Thanks... Black on Black was on my list too... http://www.texascannonball.com/modules/newbb/