Nikoctt

Looking to upgrade my exhaust on my 955 turbo. Shall I go for 2.5, 2,75 or 3' diameter?

Looking to get a custom system built from secondary cats straight through to the rear mufflers.

Is the stock exhaust 2.5 or 2.75

Thanks

J'sWorld

Its a turbo car, go for the largest you can get. You have nothing to lose.

Nikoctt

Has anyone fitted fitted a non resonated miltek exhaust 2.75 on there turbo cayenne 955 I can maybe get some feedback on

user 83838290

Save money over Miltek or whatever and put straight 3" pipes from "secondary" cats. Have them custom made.
Downpipe cats and "secondary" cats muffle the sound pretty well. Just put down everything behind the cats and hear for yourself.

JFR-

My local performance muffler shop explained they had done several muffler deletes to Cayennes, just straight pipes back from the cats. They said it would not be outrageously loud. The result was louder then what I'd planned and we put resonators on, which helped tame things a little bit. But it is still pretty aggressive sounding.

A buddy with a Cayenne thought it sounded fantastic and took his in for the same treatment, but the result was much different. His is not nearly as loud.

Why the difference? Mine is just an S and my buddy has a Turbo.

I would not hesitate to recommend straight pipes on a Turbo, but on an S one had better be ready to make some noise.

fortysixandtwo

Exhaust gas pulses are smoothed out by the turbo's turbine, which takes a lot of the rasp out of an exhaust note. This is is why the turbo was not nearly as loud as your NA.

nodoors

^This. Turbos definitely dampen the pulses. I really like the sound of the CTT with straight pipes. It sounds like an american V8, but a little more exotic with the extra raspiness. I also tried driving around with the secondary cat delete pipes unhooked (just to see what it would sound like) and it made a very deep note, but too loud and resonating inside.

The vehicle is so well sound deadened a loud exhaust sounds normal with the windows up.

JFR-

Sorry, my post was meant as a short story with a self answered question... sort of FAQ style. I can see how I failed at that last part.

I would clarify that the turbo process adds a degree of sound reduction, not just smoothing out the tone. We noticed the same mod on the turbo was simply not as loud as the NA S model.

fortysixandtwo

Hahaha, Looking at it again, it can definitely be read either way.