Hello all. It’s been a long time (6 years) since I’ve been in the Porsche game and I have a inquiry about my new to me car. Long story short, I bought a 2007 CS2 Cab in speed yellow. It’s notable features are sport chrono and x51. With this particular combination it is supposed to come with PSE.

After I get the car home and I’m checking it over more closely I find that there is no vacuum lines running to the actuators on the cans. The vacuum line at the upper left of the engine bay has a plug in it and the change over valve is just zip tied to the side of the engine compartment.

My questions are as such:
1. With all of the lines disconnected am I permanently in “loud” mode or “quiet” mode?
2. Can someone post the correct vacuum line routing so that I can reinstate the switchable exhaust functionality?

Photos for the cred.

It barely fits in the Garage. But at least it’s out of the elements.

Gratuitous a$$ shot.

 

If the PSE is on all the time you should hear the deep gurgling sound on startup and wonderful sound of deep throat exhaust.
I'd guess with the vacuum lines removed PSE would be "ON" but someone with more knowledge on subject will chime in.

All the best!

 

I bought my 06 with PSE in July and the PO also unplugged the PSE cable and zip ties it to another line. Mine is always on.

 

With no vacuum going to the valves, you're in loud mode all the time. Attached is a PDF showing retrofitting PSE to a non-PSE car whichat have the line routing info in it.

 

Thank you guys for the quick feedback. I guess that I won’t be doing anything with it since I’m in the PSE always on mode.

Reading through the doc that you posted brought another question to mind. Where are all of the technical docs stored. I have had a couple BMWs and a WRX in the time between Porsches and could always find good repositories of shop manuals and technical specs.

Thank you again. This solved my immediate questions.

 

I got that document from the Porsche dealer I had my PPI done at because it had factory PSE but someone had changed the mufflers and I wanted valved mufflers again. Not sure stuff like this is readily available.

It's pretty nice to be able to have control of the mufflers, like when leaving the neighborhood early in the morning or driving next to a cop..All you likely have to do to get yours working is plug the vacuum solenoid in and run two vacuum lines to the muffler valves.

 

I always wondered why they even have an on/off switch for the PSE exhaust. Mine always on and can't imagine any reason to turn it off.

 

They aren't very loud to me and I live in a police state as far as cars getting pulled over for any mods. I was just going to say that youtube videos of open/closed will show you that these cars are surprisingly quiet when PSE is closed or just OEM S or base mufflers are on. When I first got my car with the S-mufflers, it was as quiet as my A4 wagon. When I did the fister mod, it made the car sound pretty much identical to a PSE with the valves open. My point is, unmodded or with the PSE and valves closed, I am still surprised how quiet these cars are for sports cars.

 

3 of my 5 997's had PSE. The PSE is nice and throaty especially at higher RPM but not obnoxiously loud.
My current 06 C4 has Fister Mufflers and sounds just like PSE. Has nice gurgling on startup and throaty as RPM's increase.
Basic non-PSE quiet and boring especially after experiencing PSE sound.


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Little bump in low end torque when the valves are closed and why even in Sport mode the controller closes them at low rpm. If you look at Dyno graphs from the exhaust sellers, you'll notice on the before graph the torque curve is a little above the new curve then once that crosses over the new exhaust makes more power and torque. The PSE valves let you optimize the performance at low and high rpm

 

Well, this discussion and that on another thread have got me eager to fly into LAX and real-world test this on my car.
I recently (1000 miles ago) put on a Sharkwerks center muffler delete X-pipe.
Yes, I can finally hear the exhaust note with PSE in the ON positio, the windows up and sunroof closed.
It was not always so.
OEM PSE was ridiculously quiet, unless inputting large accelerator pedal deflection and/or high RPM (+4000).

Thankfully, I now clearly hear the exhaust note at every tachometer and accelerator pedal position .
Of course, above 4000 RPM, the engine sings with gusto, even burbling and incipiently detonating on overrun deceleration.
But I have never heard a lowering of the exhaust sound, in either volume or timbre, with the PSE ON at lower RPM ( < 3000) and/or low speed.

The engine, of course, naturally varies its own exhaust volume/timbre increase based on fuel flow and RPM changes.
I cannot find ANY reference on-line that verifies an auto PSE valve opening or closure independent of the switch position.
I've searched extensively.

Dyno graphs and hearsay do not convince me that the DME over-rides the PSE switch when in the ON position.
That is contrary to what I hear and feel in my own car.
Lack of written evidence does not preclude that possibility that the DME overrides the PSE valve switch, but I remain unconvinced that the system operates to automatically override and open/close the valves as described.

Anyone who can provide a link, document or source that supports that assertion...please do so.

It doesn't matter in the grand scheme of things of course, but I am skeptical until I can drive my car again or read an official description of how the DME actively overrides what I hear as simple pneumatically operated valves. If the PSE solenoid is being controlled for environmental (noise) or low RPM torque enhancement, it would surprise me.
But I've been certainly been wrong enough to develop a taste for this delicacy:




Thanks in advance for any hard evidence.

 

Disconnected is the best and cheapest option .... When I first purchased my car I thought it would be nice to control this feature with the Carnewal remote option and quickly realized that hitting the remote every time I jumped into the car to bypass quite mode was a pain in the **** so I removed it and just disconnected the vac plug so it stays open all the time.

 

Liste-renn,
I wanted to know exactly the PSE function on my 997.2 C4S year 2010.
My car is standard with the PSE option from the factory, so I can suppose all 997.2 have the same PSE control.

So I connected a 12VDC test led in parallele with the electrical valve of the PSE with provisory long wires to bring it inside the car.
When the test led is OFF (electrical vacuum valve OFF), the exhaust valves are opened. (valves are normally opened with a spring inside the actuator)
Results:
When you start the engine the test led is ON, the valves are opened for a couple of secondes and closed, just the time to have the vacuum inside the vacuum line.
When you activate the PSE button, the test led turns OFF, the exhaust valves are opened.
I have tested with all modes Standard, Sport, Sport+, all speeds and all engine revolution the DME don't control the PSE valve on 997.2
The valve activation is only dependant of the PSE button position.

 

I have a 997.1 so maybe the functionality is different. Mine definitely closes the valves and automatically turns on the button light at low rpm.

 

Yes, you're right for the 997.1
There is not central muffler but the shut off to reduce the noise level.
You can suppress the shut off by disconnecting the speed signal on the PSE relay.