1" 7/8 is approx 48mm , I don't see how that can fit snugly inside the silencer, surely the idea is to sleeve it as close to the inside diameter as possible , the 54mm straight pipe is literally rolling about in the silencer box.

 

Another vote in favor of this!

Just did this mod today. My experience wasn't quite as easy as some other posters here but not terrible either. A couple of notes from mine:

No 18” lengths in stock at my local auto parts store, so I bought the longer single length and cut two pieces to length from that. Seems to have worked just fine.

Used 2” ID flex pipe with no issues, fits nice and snug inside the muffler after initially very easy insertion and then a couple gentle taps with a dead blow hammer to push the end of the flex pipe flush with the outer edge of the muffler pipe.

My muffler seemed to have slightly different configuration than OP’s as it had that pesky little tube thing in both the LH and RH outer muffler “pipes.”

On removing those pipes; I went with the hole bit method another poster mentioned and, like them, burned through battery charge before cutting all the way through. I alternated between using the hole bit and a hacksaw blade to cut some more of it away by hand. Once I had it weakened up pretty good, I used the chisel end of a smallish pry bar wedged into the “notch” the hole bit and hacksaw blade made and gave it a couple good whacks and snapped it right off. (Passenger side didn’t come off totally clean so had to use a Dremel to grind the remainder down to get the flex pipe inserted.)

Both of my clamps were complete junk (one of the literally just fell apart when I removed it due to all the rust and corrosion) so after searching around for OEM clamps (and being a little shocked at the $ asked considering what they are) I grabbed a couple of Vibrant Performance 2 3/4" stainless steel exhaust clamps instead for short money (a touch over 12.00 for the pair). They fit over the exahaust tip tubing no problem, and clamp down nice and tight.

Overall loving it! Again, my install didn't go quite as smoothly as some other posters here, but the PITA factor was about a 2 at most. In the end, its a pretty much painless, dirt cheap mod that makes a nice difference in exhaust sound.

 

Thanks phL... Found your post this morning and with-in two hours finished the installed It sounds great. I've only had my 05 S for two weeks now and really enjoying it.

I also took sometime and polished the tips and painted the inside gloss black.

 

Sadly I have 2008 Cayenne Turbo.
I need to remove the bumper in order to remove the tips.
Also I couldn't find the exhaust tube anywhere. Even online, they don't ship to Saudi Arabia or it'll take 3 weeks min.

Thanks for the mod anyway!

 

A bypass tube is not necessary on the GTS.

By removing and plugging the vacuum lines to the actuators at the muffler it will
sound like the clip.

Takes about 10min. and your done.

 

Finally got this done to my Turbo S 06 model , using flexi exhaust with an ID 57mm / OD 62mm , cut to 390mm long leaves about 5mm sticking out before fitting the tail pipes to help if they are ever to be removed. This for me was the perfect size of pipe as it slid in firmly only needing a light tap and will not rattle or vibrate.

 

Where did u get the flex tube from?

 

Dingbro, I'm in the UK

 

I found it on Ebay but not sure if it will fit in my 08 CT. ID 60mm / OD unknown.

Do you guys think it'll make the same sound? even if I bend the tube to fit in the muffler.

 

60mm ID would not fit in my exhaust (06 turbo S) the 57mm ID was a nice snug fit however your car will be a 957 so may be different .

 

Here's my feedback on my first attemp after ordering a flex pipe (ID 57mm - OD 60mm) for my 08 CAyenne Turbo

The size was okay but the problem is the curve of the muffler pipe as shown on the picture below.




Flex pipe couldn't make it through the curve.
And the only 2 options is to go with 57mm OD so it can fit.
Or to cut the muffler curved pipe to fit the flex pipe then return again.


Since the flex pipe took 7 working days to be delivered. I have no patient to order the correct size and wait


Cheers

 

Gents - I just did this on my 05 CTT and I didn't get the same result. My truck is louder, but maybe only 5-10% louder. I ended up removing the tips and installed 2" flex pipe which was 18" long and fit the entire pipe into where the tips connect to the muffler.

Is there something else that I am missing? Unfortunately if this does not give me the aggressive sound I seek, then I'll have to install the cat bypass pipes.
Cheers

 

I just went back and looked at all the pictures and it appears that my tips were somewhat flush with the outlet pipe. They wouldn't go in all the way. However my flex pipes were 18"

Anyone else who has a CTT have any thoughts?
Thanks

 

Doing this mod on 2006 S

Inside the muffler I can see a perforated tube that is offset from center of the external view.

The offset disallows a simple push in as the flex stops at that offset, with about 5 inches of flex outside of the muffler.

What is the secret to continue across that?

And how far from the outside of muffler output should I be pushing that in?

 

2 OD x 18 Inch 16G 304 Stainless

This was the answer