I do not think this thread needs much introduction. I built my first full exhaust for this vehicle about a year and a half ago with 2.75" straight through pipes and straight through mufflers (view the build here). I knew that there would be some gains above the anticipated 600 hp, but did not know what to expect. After visiting the dyno, I made MUCH more power than I anticipated with just simple bolt-ons; about 692 hp /715 ft lbs of tq (view the dyno session here).

After all was said and done, it became clear that all the exhaust size calculators said that I should not be able to make this much power with 2 2.75" pipes; meaning the pipes were maxing out flow at the top end. So following that theory, I should have some extra power waiting for me, if I can just step up to a full 3" exhaust system. To top that off, a full 3" system should be able to support upwards of 1000 hp. So I will be replacing everything after the primary downpipes and out to the muffler tips for more flow. And the power journey continues...

DISCLAIMER

This thread is not intended for anyone to copy or imitate. I am not endorsing any products or companies. I am merely showing the steps I went through to get this working for me. If you think you want to do something similar, contact your local Porsche dealer and ask for recommendations and proceed at your own risk. I assume no responsibility for any work performed on your vehicle.

SPECIAL NOTE

Given the lengths of some of my most recent threads, I have opted instead for a photo montage punctuated with brief notes. Also, given the scope of the project, I forgot to take some key milestone pics. So expect some gaps in the image timeline.


PHOTO MONTAGE

Pepper is up in the air and prepped for surgery...





This is a pic once I was 60% complete. A good lineup of tools for the job, including both my MIG welder (tacking) and TIG welder (finish welds).



The puny 1/4" secondary flanges will be cut off and replaced with beefy 1/2 304 flanges



Tacked up and clamped down




Look, twins! V-Band flanges used throughout



Custom 3" X-Pipe



Inside of X-Pipe





Build out onto the X-Pipe to the secondary v-band flanges



Trimming and angling the end of the X-Pipe towards the resonators



Large Resonators (aka. premufflers) on a placement jig



Welded together since clearance is very tight between the saddle gas tanks



Brief clearance check under the passenger door



Placing large resonators





X-Pipe section complete with resonators



Basic bend forming



One of two pipes leading from resonators to rear muffler



Both pipes from resonators to rear muffler clamped down and about to be finish welded





Muffler height placement





Version 1 -Complete system overhead pic (tacked only)






Version 2 - Had to remove large resonators (too quiet) and install smaller bullet resonators. Everything else is the same.



Even though everything is 304 Stainless Steel, I decided to give it extra corrosion resistance since the NE winters are brutal.






Decided on a two-tone paint. Flat black from the rear and the higher temp resistant silver paint for the rest.

 

It may or may not have been clear, but there were two final versions of this exhaust. The first version was made with the large resonators in line before the muffler, but ended up being too quiet for my tastes. I know, I must be crazy to say that an open 3" exhaust was too quiet. The best way to describe it is that I had inadvertently filed down it's fangs... think less wild wolf, more Golden Retriever

Here judge for yourself:

Video: Exhaust Sound Clip - Version 1 - 4K RPMS



For the second version, I removed the large resonators and installed small bullet resonators in its place, so it would let out a little more gurgle. But still keep the 3" system under control


Video: Exhaust Sound Clip - Version 2 -4K RPMS


Now that is much MUCH better!

I will update this post once I can get video and audio of the system under load and on WOT.

 

For anyone who may be interested, I will be putting up a sale post in the classified for my 2.75" full system from the custom secondaries all the way to the SuperSprint mufflers and 3" tips. This is the same system that has been proven during my last dyno session. See video link in Post #1.

https://www.6speedonline.com/forums/...no-proven.html

Due to its size, I am trying to sell it in the NY metro area. If you are close, I can even help you install it over a weekend. Send me a PM if interested for a full breakdown.

 

Reserved for after video response!!

 

For context, I thought it would be fun to put up a picture of all the spare bends and cuts that I made. This is about 80% of the leftover cuts...

 

Very cool. I'm loving the sound

 

Awesome sound!
Great deal to have assistance installing too - what an offer!
Someone is gonna purchase a sweet system.

 

Thanks! I think so... still looking for a good home. Definitely a lot of love went into both systems and sound second to none for the Turbo.

 

surprised the exhaust system hasn't been snatched up yet...

bump...

 

Me too!! I guess the Cayenne performance community is hibernating through winter. I imagine that as soon as it starts to get warmer, it will move quickly.

Thanks for the free bump!

 

Sounds good, that looks a like a lot of work!

 

Well done RM! Very impressive!! Wow! Did you feel any difference in power?

 

Thanks man - good to see you here! Honestly, I was only expecting this to probably give me about a 20 -30 hp bump over my 2.75" system with a better hp/torque curve. It is hard to notice that type of gain on a 700 hp / 3 ton vehicle without quantifying it on a real dyno.

However, experiential experience was telling me that it seem to gain speed at a moderately higher rate at WOT on the highway. This was noticeable once you stayed on the throttle for atleast 15 seconds, plus. Given that the gain will be biased on the top end, this is completely plausible.

With that said, this Y-Pipe install really woke up my Cayenne and has it rocking so hard that the first day out, I experienced slight neck discomfort. The two mods really compliment each other

 

Up front, I'm brand new to the forum. I fabricated my own air intake and started looking to fabricate my own exhaust when I ran across your thread. To be honest the only reason I joined was to ask you the following questions about your sweet set up: Where did you you get the .5" secondary flanges and the hangers? Where they an exact match to the primary's? Also do you have a list of the fabrication components you bought; 45 degree elbows, 90 degree elbows, feet of straight pipe etc...

I saw your disclaimer up top; so if it is more appropriate to PM you in regards to where you found the fabrication components I will do so..... just as soon as I figure out how to do that....

 

Impressive! Wish i would of stumbled across this thread sooner. Great work!