Hey Jo,

If your answers in bold are true, though, that would indicate that both PSE on/off positions are the same. I know this is rather annoying, but hear me out:

PSE OFF: Exhaust leaves the headers, enters the PSE center mufflers, then goes into the side mufflers, then exits via the first set of tips. This essentially muffles the sound twice; once through the center mufflers, and then through the side mufflers.

PSE ON: Exhaust leaves the headers, enters the PSE center mufflers, and then exits via the second set of tips. It does not touch the side mufflers at all, making it somewhat louder and deeper.

If this is correct, then the side muffler bypass pipes (or aftermarket side mufflers) will only affect the PSE OFF setting on PSE-equipped cars.

?

 

Forgive me, IDK how to multi-quote Sorry if I wasnt clear on my bolds.

PSE off, you are dead on. cats->center->side muffler/pipes only
PSE on, allows some (but not all) exhaust through the second set of tips, much still passes though the the side pipes. cats->center->sides/both tailpipes

Look at it like this way, there is an exhaust pipe that connects to the center at all times and exhausts all the gas and cannot be changed. The only time that pipe doesnt take 100% of the load is when some is diverted, and that is when PSE is on.

Yes, I think there is some validity to your point about the way bypass pipes would effect PSE equipped exhaust. PSE off tone A, PSE on tone B...

Another tidbit, the PSE flaps also change with throttle speed/input. Even when "on" the flaps actually still open/shut, I first saw this in a video and confirmed on my car, of course I was stationary so Im not 100% sure it happens when its moving.

Then again, there are flaps on S models without PSE that are located near the middle of the center muffler, I have no idea how/if they effect the sound. However IMO when you factor that into the buying/engineering equation, I think PSE purchasers are getting screwed considering there is no extra plumbing involved. When I had PSE installed on my Cayenne S, they had to install vac lines all the way to the front, if those lines were already there and my muffler already had valves, I would be pi$$ed to have paid extra money for different cans.

If you watch the Fabspeed video, its a good reference point for an S with PSE.

 

I had the Sharkwerks side can deletes and I hated it. j080808 has the center replacement, correct?

The side cans means there is zero difference when the PSE opens up - it droned all the time for me and was quieter up top than my Cargraphics x pipe.

The center delete removes the valves from both the S non-PSE and the PSE.

PSE is fully open when moving - it operates differently at a standstill. Above 3500 rpm, or when the button is on, the valves open up. Porsche does some trickery when you let off the gas (opening it for a bit and then closing to get some pops, etc).

Anyway, I can confirm that open, almost no exhaust comes through the side mufflers. (I locked the valves open by hand and revved the car, with my hand near the tips, not extremely scientific and more gas comes through the exhaust while under load, but it satisfied my curiosity. I also watched with my gopro and when the valves opens at 3500 rpm, just about nothing goes out the outer tips.

I think the valved x pipe solutions are the way to go. I really want to cut open a set of PSE side cans as they are different part numbers but look identical.

 

Interesting. In terms of the valves on a non-PSE car, you are correct. They are there. Kit had a video with his Cargraphic x-pipe showing how they work. Essentially, the valves stay open at idle, closed when driving over 5mph, and then open again over 3300rpm.

Keep in mind that non-PSE cars have a different, larger muffler. While both are valved, the PSE muffler isn't as restrictive (hence, louder) and gives you complete control over the valve settings.



Great, thanks for the info, guys. I guess we can all somewhat agree on the PSE on/off exhaust route at this point.

Should be getting your x-pipe today, Kit. So excited.

 

So what if you just bought the OEM PSE center muffler without the switch and software? The PSE center looks like it has an X-pipe design. Wouldn't that just be like PSE open all of the time and give you the same OEM PSE sport sound?

 

I'm actually pretty sure that would work fine. The PSE center section is actually cheap - less than $1000 and sounds quite nice.

I know it'd fit. The PSE is not a traditional X pipe if you look at the diagram, though, it's not straight through, when the valves are closed, it flows through a number of right angles, even open, the gases have go to through a chamber and a 180 to get out.

I've actually noticed that most aftermarket exhausts have some pretty major gains in the midrange. (very little peak) The best part about it is the smoother power curve, you don't get the lumpy delivery 3000-4000 and 5000-6000

 

The valves are still there in the PSE muffler, and the non-PSE cars have the control system we discussed above. I'm assuming that it would work like Kit's Cargraphic X-pipe: open at idle, closed above 5mph, and open again above 3,xxxrpm.

 

I have the Fabspeed headers paired with the FVD x-pipe = glorious sound! I have the Sharkwerks side exhaust as well (mainly for weight reduction and to get the heat from those big-a$$-cans away from my rear tires on the track. Car is loud - ain't care....

 

What I would be looking for is an amplification of the pse on effect. A ten to twenty percent increase in noise with the pse off would be acceptable.

 

Only way to achieve that would be a set of sport headers with cats, or to replace the PSE mufflers with a set of valves mufflers / valved x-pipe.

Here's a video from Maxspeed Motorsports that lets you clearly hear the difference between a stock 991 (think stock PSE off), then their x-pipe with valves off, and then valves on.


I'll be installing my Cargraphic valved x-pipe next week and will have lots of sound clips comparing it to the stock PSE system. You may want to check those out.

 

message us for best pricing on fabspeed products

856-382-7543

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very confusing...............I, like several others with PSE, are only looking for 15-20% in sound volume and maybe a little HP increase and NO DRONE!!!


Is it Fabspeed headers (+17 hp claim ) for $2k
Is it Sharkwerks side mufflers?


Is it Nothing?

 

Get a valve controlled x-pipe, like FVD, nice sound, no drone.

The HP numbers on the Fabspeed headers are a little bit on the optimistic side but not all that unrealistic. With the stock exhaust the headers won't give you that much more sound.

 

Stumbled across this thread while doing 991 exhaust research and wanted to clear up some confusion about the 3 types of exhausts avaliable from the factory. The attached images should clarify any future curiosity.

Porsche 991 3.4L basic exhaust system. twin branches w/ one common center muffler and two main side mufflers (55mm). No cross bank linking of exhaust flow.



Porsche 991 3.8L basic exhaust system. Four branches w/ common center muffler w/ two flap controlled bypass pipes and two side mufflers (55mm intake, 52mm exhaust). Bypass flaps are automatic underload, not user controlled. No cross bank linking of exhaust flow.



Porsche 991 3.4 & 3.8L sport exhaust system (PSE). Four branches w/ common center muffler w/ two switchable bypass pipes and two side mufflers (55mm intake, 52mm exhaust). Bypass flaps are controlled by mode or independently (sport, sport+ and or PSE button). Note: PSE includes cross bank linking of exhaust flow for increased resonance.