1) Can someone explain the basic operation of the PSE valve opening? For instance is it based on RPM, pedal position, both?

2) It appears that PSE only comes with a special dash button on cars that do not have a 'Sport' button. Is this correct? If so does that mean that Sport Chrono equipped cars cannot be in sport mode without activating PSE?

 

1) RPM... but you can mod the system so that the valve is either always open or always closed based on switch position.

2) Not sure about the special switch. Yes, with Sport Chrono and with OE PSE install you cannot have PSE open and Sport Chrono off or vice versa. However, I have seen many installs where the dealer added an extra switch the cubby hole that allowed the driver to manually control the valve.

In the end I do not think PSE is worth the money. The sound is okay stock... very nice with headers and cats. But its heavy and expensive....

Jason

 

WRT #2, yes. Sport Crono cars have the sport mode and exhast mode linked. So if you go into sport mode, you get the sport exhaust along with the throttle mapping and relaxed stability management.

PSE cars can easily unplug the PSE controller in the engine compartment so that the PSE is always on.

 

Here is the basic operation of the PSE:

The Porsche 911 mufflers have 3 chambers in them . With the PSE , you get an extra exhaust pipe from each muffler ,which exits aready from the first chamber . So in effect,you bypass 2/3 of the mufflers.

Each bypass pipe has a vacuum activated valve in it.
An electric ( 12v ) solenoid valve controls the vacuum flow to the valves.
When the solenoid OPENS , it allows the cars vacuum to CLOSE the PSE valves .
The solenoid valve is normally closed .No power = valve CLOSED .
The PSE valves are normally open.
No vacuum to the valves= valves OPEN .

Per factory setting :
when the PSE is active ( bypass valves open ) at speeds below ~ 50 mph , when the car is aggressively driven , the valves will close and open again, as soon as the accelerator pedal is relaxed etc.
Above 50 mph they stay open , regardless how hard the car is driven.

If your car has Sport Chrono,you have to put the car into the "sport" mode to activate the PSE ( hard suspension and all )

In cars without Sport Chrono, a dedicated PSE switch is added ( it has the dual exhaust pipe symbol on it )

It is very easy to bypass the factory cut-out or to activate the PSE without having to activate the Sports setting, by simply installing an on-off switch into the 12 v power wire going to the electric solenoid valve
(remember: no power to the solenoid, PSE = loud )

Or, you can just unplug the 12 v power to the solenoid
( that's the orange plug just above the filter box) but then it will ALWAYS be loud. And I mean LOUD .Lol )

I installed a 2 way switch into my ashtray ( see photo)
that way I can cotrol the PSE from inside the car, anyway I like .
In one position , everything works per factory setting.
In the other,the switch disconnects the 12 v to the solenoid and the PSE is always on )

Note : all of the above disconnects/ mods can be done without causing ANY harm to any of the cars systems .

In closig:
as we all know, all normally aspirated engines requires a certain amount of back pressure for increased torque at lower RPM's.
Above ~ 5200 RPM, less backpressure will result in a few extra HP.

Presumably, the standard factory exhaust system is designed as a compromise between the two , as determined by the Porsche engineers who have been designing and perfecting their engines for over 50 years now

The PSE sytem is designed to give us the best of both worlds. Higher torque at lower RPM's and some more HP at the high end ( not to mention the pure Porsche sound )
To my knowledge, no aftermarket system is able to do that .

I leave it up to you to believe the ... "dyno proven " claims of some aftermarket muffler welding guru ( who neglects to mention the equal or more torque losses ).....

My personal opinion is that there probably will be some gains when bypassing 2/3 of the mufflers , even though Porsche makes no such claims ( well , at least as much as claimed by the aftermarket "experts" )
But what do I know . Lol

( Sorry for the long winded post )

 

Thanks. That is some excellent info, and nice mod.

 

I installed a 2 way switch into my ashtray ( see photo)
that way I can cotrol the PSE from inside the car, anyway I like .
In one position , everything works per factory setting.
In the other,the switch disconnects the 12 v to the solenoid and the PSE is always on )

JCS ....What wire on the orange plug did you connect the switch to? I like your idea...........Thanks

 

I was at the shopping center today and started my 997.2 S with PSE. I turned on the PSE and the "roar" activated the truck's alarm that was parked next to me. I am so happy with the 997.2 PSE.

 

You can get to the control wiring by removing the aluminum cover
behind the passenger seat .
The carpet cover can be removed by just lifting it out ( be carful , the backing is molded ridgid foam . Start by gently pulling up in the middle of the car and then slide each side out from under the side panels )

The 12 v power wire to the solenoid is red/purple and the ground wire is
lt. green .
They leave into the engine compartment in the upper left corner (looking toward the rear of the car )

( you can also splice into the wire directly at the solenoid , but then you need to figure out how to get the wires from the engine compartment back to the switch inside the car )

I cut the 12 v wire and spliced a wire into it , which then was routed to the center console .
I used a 2 way switch . In one position , the circuit is closed and everything works per factory . In the other, the circuit is open , no power goes to the solenoid and the PSE is always on.

 

I have a 2009 C4S with PSE, Sport Chrono, PDK and Sports PASM. I have an independent switch for the PSE. If it is off, I can turn it on. If it is on, I can turn it off. This is just like the Sports PASM switch. All factory installed during the build.

 

So, it is not DME linked, as the previous versions were, and doesn't close on it's own at certain speeds for sound controll?

 

When PSE is turned on the volume seems to change some with throttle position but not by much. I understand the PSE for the 997.2 with PDKs is a little different from earlier versions. I don't know the technical points, but I know I can turn it on and off at will by just flipping the switch.

 

[quote=JCS;2614049]

I installed a 2 way switch into my ashtray ( see photo)
that way I can control the PSE from inside the car, anyway I like .
In one position , everything works per factory setting.
In the other,the switch disconnects the 12 v to the solenoid and the PSE is always on )


Ok - switch & wire from Radio Shack. What did you use to make the switch mount? Looks like a piece of black plastic - source? Thanks.

 

Thx for this post, JCS. It explains everything and now I can enjoy the true Porsche exhaust sound throughout the rev band. To keep it simple, I just disconnect the brown (orange to some) connector to the solenoid. When I have my partner in the car, I just re-connect it for normal (quiet) mode. So far, no CEL.

 

You don't have to worry about getting a CEL . The PSE valve system has nothing whatsoever to do with it .

Just a suggestion , it may be a good idea to occasionally re-connect the switch and "cycle" the valves to prevent the exhaust crud from accumulating on the valve seats (the exhaust is not exactly the cleanest place in the car )Lol

 

Thanks for the reminder to cycle the PSE valves on and off from time to time.