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Not sure with the Porsche PSEs, but with the OEM system on the C6 gen Z06 Corvette, there was simply a dedicated fuse you removed that deactivated the system and caused the flaps to stay open all the time by default.
I think all of the Porsche PSE systems use an electric vacuum solenoid that when you start the car, activates, and pulls the valves closed - at least this is how the 997 one works. If you can trace the vacuum line(s) up to the solenoid, yes, you can unplug the electrical connector which will leave them open all the time. Porsche makes them open and close for 2 reasons though - 1 is for noise ordinances in Europe, but the other reason they close at low RPM even in sport mode is to create some back pressure, which increases low wnd torque and helps around town. Then once you're off and running again they'll open back up, increasing flow and power.
All the valve assemblies I've seen from all the main manufacturers look to be the same, jut mounted in different places - I'd be surprised if the Cayenne GTS is unique in this respect. They usually look like this (valve with the little rod that moves in and out from the vacuum).
I think all of the Porsche PSE systems use an electric vacuum solenoid that when you start the car, activates, and pulls the valves closed - at least this is how the 997 one works. If you can trace the vacuum line(s) up to the solenoid, yes, you can unplug the electrical connector which will leave them open all the time. Porsche makes them open and close for 2 reasons though - 1 is for noise ordinances in Europe, but the other reason they close at low RPM even in sport mode is to create some back pressure, which increases low wnd torque and helps around town. Then once you're off and running again they'll open back up, increasing flow and power.
All the valve assemblies I've seen from all the main manufacturers look to be the same, jut mounted in different places - I'd be surprised if the Cayenne GTS is unique in this respect. They usually look like this (valve with the little rod that moves in and out from the vacuum).
Yep, Z06 system looks very similar, same deal basically. I think you're probably correct in that if the OP unplugged the electrical connection to the system, they would stay open (basically the same principle as removing the fuse from the Z06 system). So the PSE doesn't also use a dedicated fuse for the system alone, as opposed to having to disconnect the electrical connection?
Yep, Z06 system looks very similar, same deal basically. I think you're probably correct in that if the OP unplugged the electrical connection to the system, they would stay open (basically the same principle as removing the fuse from the Z06 system). So the PSE doesn't also use a dedicated fuse for the system alone, as opposed to having to disconnect the electrical connection?
On the 997, I don't believe it's on its own circuit, so assuming the Cayenne is the same. Porsche electrics are often so intertwined like for Sport Chrono, PSE, shock modulation, that it's usually less problematic just to disconnect the electrical connector than pull a fuse that might also control other things.
Not sure with the Porsche PSEs, but with the OEM system on the C6 gen Z06 Corvette, there was simply a dedicated fuse you removed that deactivated the system and caused the flaps to stay open all the time by default.
Could the PSE be that simple as well?
How was low rpm torque? Do you feel car was less responsive?
I think all of the Porsche PSE systems use an electric vacuum solenoid that when you start the car, activates, and pulls the valves closed - at least this is how the 997 one works. If you can trace the vacuum line(s) up to the solenoid, yes, you can unplug the electrical connector which will leave them open all the time. Porsche makes them open and close for 2 reasons though - 1 is for noise ordinances in Europe, but the other reason they close at low RPM even in sport mode is to create some back pressure, which increases low wnd torque and helps around town. Then once you're off and running again they'll open back up, increasing flow and power.
All the valve assemblies I've seen from all the main manufacturers look to be the same, jut mounted in different places - I'd be surprised if the Cayenne GTS is unique in this respect. They usually look like this (valve with the little rod that moves in and out from the vacuum).
Thank you very much Pete!
What parameters trigger the valve? I have secondary cats bypassed, do you think (for performance) I need to trigger it later or earlier? (if the logic is adjustable?)
09-21-2017, 01:03 PM
Cayenne GTS 958.2 sport Exhaust valve ALWAYS OPEN?
