I just had a full GMG WC Center Exit exhaust installed on my 997S. I had the PSE before the install (the car came with it when I bought it used). My question is, how does the PSE work. I sold the mufflers before I was able to see them in person and pictures are not clear.

Is the PSE just use a valve in the pipe to regulate sound? Or does the valve redirect exhaust flow? From pics and explanations it sounds like it is just a valve in the tube. If this is true then shouldn't it be possible to splice the valve into aftermarket systems to continue to use the sport button to regulate sound? This would not be economical for guys that never had PSE but would be for guys that have old PSE mufflers laying around and/or already have the wiring harness installed.

For guys that do not have old PSE's laying around or the wiring harnes, there are aftermarket valves available. However, I am not sure how these differ from the valves that Porsche uses.

Thoughts? I am thinking about splicing some PSE valves into my WC system. Mostly just for kicks and like projects!

Jason

 

Yeah, it's just a vacuum activated valve that opens up the bypass. You could surely use the OEM switchgear to operate another valve, which would be a great idea, unless you are running bypass pipes that is.

Great project.

 

I'm not sure what you mean by valves. The PSE has a solenoid/valve in the engine compartment that takes the electrical signal(s) for loud/quiet settings, and applies or removes vacuum to the tubes that run to each PSE muffler. On the mufflers, there is a pneumatic diaphragm that operates a lever that moves a baffle inside each muffler. In loud mode the baffle causes the exhaust gases to bypass one part of the muffler and exit through the bypass pipe.

 

Yeah, "baffle", "valve", or "Butterfly" was curious if there is actually a bypass or is it just the baffle causing the sound variation. For example, Vette's just have a butterfly valve in the exhaust that opens and closes. When closed the Vette is quiet, when open the Vette is loud. Many "Valvetronic" systems are this simple but I am aware others are actually re-routing exhaust gases. I assumed the Porsche system was the latter but I did not see an actual bypass in the PSE. However, I never really examined mine up close before I sold it.

Jason

jason

 

Just to be clear, in the Porsche PSE, the moving baffle is inside the PSE muffler.

 

Yep, this is the info I was looking for. Thanks

Jason

 

The moving baffle is not inside the muffler - it is inline with the small exit pipe on the back of each unit. On the non-PSE muffler there is a single outlet (from about midpoint along the rear edge of the muffler can) for all of the exhaust flow. On the PSE muffler there is this exact same center outlet plus one additional smaller diameter outlet from the top edge of the muffler can - this line has the valve in it. On the PSE the standard center exit leads to the larger chrome tip on each side, and the PSE secondary outlet goes to the small one. When there is vacuum applied (PSE 'off') the valve is closed: so all exhaust flows through the stock routing and out the biger tips. When there is no vacuum (PSE 'on') the valve opens allowing most of the exhaust out the smaller pipe. This pipe exits the muffler can about 1/3 of the way through the muffling - skipping the last 2/3 of the baffling.

In this picture the mufflers are upside down: inlets are at the top, the stock sounding outlet is in the middle, and the PSE outlet is at the bottom. That lump just after the elbow coming out of the muffler is the valve that opens or closes the extra outlet. Cut that outlet off and weld it closed and you have a stock muffler. No difference inside the can.

 

Great explanation by johnstoy. If I had looked at my own photos (below) I would have remembered the valve is in the pipe, not in the muffler. Here are some photos of the PSE mufflers from different angle, as well as a stock muffler.

 

Cool.....good explanation!

Jason

 

Just something related...to regulate the PSE, people say there's a button on the centre console. Is that the original "Sport" button to which the additional wiring of the PSE will be connected? I presume that PSE doesn't come with an additional button, right?

 

Depends on what options (Sport Chrono) the car came with. If the car has Sport Chrono I believe the PSE is tied to it and no separate button is installed: PSE is on when in Sport mode. If not, there is a PSE specific button (goes in the Spoiler/PASM/PSM strip) with a little symbol that looks like the PSE tips. I thought I had a picture somewhere but can't find it. A lot of people custom wire their PSE for full control (using an additional switch) so the DME does not close the valve at 'residential' speeds.