As i slowly knock out the 200k major service items on my list (only rear hatch struts left woo hoo!, and a cracked bumper ), I'm looking to start modding the pepper.

I'm considering installing secondary cat bypass pipes on my 04 CTT. Obviously i know of the HP and reduced boost lag benefits, but also curious about the noise. Personally, i love the rawer sound - one of my favorite mods on my 03 BMW M5 is the muffler delete - not too loud at idle and cruising around town, but amazing at higher revs.

The concern though, is the wife. I got away with the muffler delete on my M5 because she was my girlfriend back then, but she always complains that it's a bit too loud inside the cabin, and she can't make phone calls, or even have a conversation with me because of the noise.

All the videos that show a pre and post bypass install always seem to be from outside the cabin. They sound amazing to me, of course, but i was curious how it sounds from inside the cabin with all windows and sunroof closed.

Anyone who has installed these care to share, or point me towards some videos?

Thanks!

 

I hate to hear my wife on the phone when i'm driving so the louder the better for me. Thinking about installing four 15inch jbl's to tune her out. Lol!

Hope you get your answer though.

 

I'll be happy to make some in-car videos for you this evening if you'd like. Im not sure it will be noticeable though. Its a very subtle change inside the car. Mine is 100% stock other than secondary bypass.


My fiancé did not notice a change in sound level at all. Honestly, even I barely notice it inside with the windows up. With the windows down, its much more angry and snarly sounding if you're aggressive with the throttle, but the Cayenne is so solid and well insulated that as far as noise goes its never intrusive.

 

This^^^. I installed the sec. bypass pipes on my 955 CTT and it sounds pretty much the exact same from inside the cabin with the Windows up. With the windows down it is a tiny bit louder in the cabin but not much at all. But from the outside and rear of the vehicle it is a decent amount louder and just sounds mean, cold starts sound amazing. I love everything about them on my 955 CTT.

 

The only thing your wife will notice is more people on the street turning their heads to look as you drive by.

 

Cold starts are tremendous, I often stand outside the car to hear it with the door open and my foot pressed in on the brake. Best part of left hand ignition That sharp bark on ignition and then the lopey growl as it warms up is something I look forward to in the morning.


I actually have taken a few videos from this on mine on mornings when it has sounded "extra" good

 

Fantastic! These response are pretty much what i was hoping for. I'm going to go ahead with this. Thanks a lot guys!

If you could post up some of these videos of the cold start, that would make my day.

 

I'll put some up this evening in this thread, it wont let me upload the HD quality to youtube without connecting to wifi

 

Dude do it! On my 957 s it isn't noticeable at all inside. In the morning, like stated above, it has a bit more noise to it as the motor warms up. Believe it or not, the thing that added the most noise was my fab speed exhaust tips haha. My set up is fabspeed cat bypass pipes to stock cat back to fabspeed tips. Trucks very loud now but still on the inside, you can't hear much of anything.

 

I just had the Fabspeed Secondary Catbypass pipes installed on my 2008 Cayenne V6. The sound is more aggressive, especially at 3k rpm plus. I'll eventually upgrade to the Fabspeed Maxflo mufflers and tips, but I'm happy with the sound now. The sound from the interior isn't bad either.

 

Very subtle, I have them on my TT, I also have the thick privacy glass so that makes a difference as well. Go for it!

 

Check out my videos I posted on this forum:
https://www.6speedonline.com/forums/cayenne/358864-exhaust-mods.html

 

Here is the youtube video of cold start idle that I promised. Sorry for the quality, its not something I ever intended to share, its just something I made for my personal enjoyment/data collecting.

 

I did the bypass too in my 955 TT. The difference inside is almost imperceptible, even with windows open, my wife tells me the only way i will ever hear it, is to put a microphone next to the tips . But when she heard it form the outside rear she told me that its too loud . For me the best part is also the cold start, because its the only time i can come to the rear and hear it...

 

grdlaw, seattleturbo, thanks a lot guys! this is fantastic. pretty much exactly how i hoped it would be. some growl, but not too obnoxious at idle, tame inside the cabin when the pedal isn't to the floor, and that satisfying madness at full throttle.

perfect. :-)