Catharpin

The valves on the non-PSE S model open up around 3300 RPM. Does the PSE have any similar setup, or is it just open/shut depending on the switch setting?
Does anyone know for sure? I ask because I have a valved exhaust and I am trying to decide if I want to have the PSE switch programed.

shyamvenky

Yep - they do open up at around 3300 rpm. I find it annoying at times => I want my PSE switch to be really faithful - off means off, but sadly only an ECU tune can address this methinks.
But at least I have the switch to keep the valves open all the time => for that purpose I think you definitely want the PSE programming

Catharpin

@shyamvenky Thanks for the reply. I already bought the switch, I just need to have it programed. I had heard you need to get a "code" to activate the button, is that for .2 only? I have seen some post on here they got it programed without a code.

RP4S911

Essentially the 991.1 S/4S has valves stock that open up at a certain rpm. The difference is that when you get the PSE exhaust (with the button) you can manually open the valves before it hits that 3/4k rpm mark and leave them open. It's very similar to those with the automatic wing, yes it goes up and down automatically, but you have a button to manually raise and lower it at will. Hope that makes sense.

James88

I have a 991.1 C2S, without PSE, I can hear it open up as revs increase with some crackles and pops.

vanlieremead

docskeet

What manual is this page from?

tilac999

Image doesn't apply to N/A engine. 991.1

Is the center section the same for non-PSE 991.1?

bb964

If you install and code the PSE button on a non-PSE 991.1 S/4S, the valves will operate just like on a PSE car. The only difference is the sound itself.

bb964

non-PSE 991.1 (non S) does not have the valves. Here are the non-PSE S vs PSE side by side.
(before I get yelled at, the 15W-50 is not for the 991)

RP4S911

Right. I believe the rear muffler is slightly different to accommodate a sportier sound at WOT.

James88

So the NON-PSE 991.1 C2S has vavles as in your photo at top right & left?

James88

1st time I have heard this, have you seen this done? This would be ideal for me as I like the sound and would be great if I can open and close valves via a button

bb964

Yes, Top is the Non-PSE C2S/C4S , bottom is PSE C2S/C4S - same two valves, but in a different location.

bb964

I have done this. I first had the dealer code the newly installed button with the existing non-PSE S muffler, and then installed the PSE muffler. It is a good way to make sure the coding was done correctly before disconnecting/modifying the vacuum lines to the PSE muffler. With open valves at lower RPM's you can definitely hear the difference in sound even with the standard muffler