996 PSE valve operation query

[ThePrincipal]

I’d like to retrofit a 996 with PSE, before I go ahead can I confirm how the system works?

I know the switch on the dash opens and closes the valves, but do they stay that way? I.e if I want the valves open will they stay permanently open or do they close after reaching 30mph or similar?

If they do close again, is there a manual override available?

Thanks in advance

[james.a.c.911]

On the 996 the switch is just on or off. Ie no opening above a certain speed, etc.
Different manufacturers off the valves have different default positions but .. most of the time i believe the default is open (ie loud), and you need vacuum in the system to then switch to quiete (ie the engine must be running)

[m444ttb]

As standard the 996 system does switch back to quiet (from starting loud) across a low speed range. I can’t quite remember what that range is though. You can remove a resistor in the relay to stop that happening though.

[ThePrincipal]

Thanks for the replies.
So the system automatically starts loud, but quietens down after vacuum pressure has built up, but other than that, if I want to leave the valves in the open position, they'll stay like that?

[james.a.c.911]

From my experience (which is original PSE button on dash but aftermarket switchable silencers) - yes that is correct. When on loud its always loud with all the dron involved.

What M444ttb is suggesting is different - he is saying it goes quiete at the lower rev range even ifon loud. That is not my expericence by may be the case with the original factory PSE.

[GT6 Jonsey]

My 996 has factory fitted PSE. It starts every time in the loud position and stays like that unless it is turned off from the button on the dash which can be done immediately. There is no drone with it when set loud at any speed/RPM. Not sure if this is normal but it’s how mine works any hoot. Fitting 200 cell sports cats to it soon to add to the volume

[philnotts]

I have the PSE fitted to my 996... The default is PSE on from start up and will stay on until you switch it off via the button on the dash.

However from 30-50 mph the values would close regardless... I removed the rely to stop this , so the PSE is on all the time with no cut out.

[m444ttb]

GT6 Jonsey said:

My 996 has factory fitted PSE. It starts every time in the loud position and stays like that unless it is turned off from the button on the dash which can be done immediately. There is no drone with it when set loud at any speed/RPM. Not sure if this is normal but it’s how mine works any hoot. Fitting 200 cell sports cats to it soon to add to the volume

As my factory PSE was rotten I swapped it for a TopGear switchable system along with their 200 cell X-pipe cats. In quiet mode it’s as quiet as standard on a cruise. With the valves open there’s a little drone that isn’t there with the standard PSE so I tend to switch mine to closed on the motorway etc. Putting your foot down with the valves open is pretty sweet though. Way louder than standard.

[m444ttb]

To add, I had the TopGear exhaust noise tested at Castle Combe last year. 5000rpm static test and it was 97db closed and 105db open.

[james.a.c.911]

m444ttb said:

As my factory PSE was rotten I swapped it for a TopGear switchable system along with their 200 cell X-pipe cats. In quiet mode it’s as quiet as standard on a cruise. With the valves open there’s a little drone that isn’t there with the standard PSE so I tend to switch mine to closed on the motorway etc. Putting your foot down with the valves open is pretty sweet though. Way louder than standard.

Thats interesting.
I have the top gear x-pipe and dessignteck switchable silencers which are effectively made by topgear and just rebranded. So same set-up.
On loud it's really loud and drones a bunch. I've had a valve fail on a loud track day (brands at 105 bd) and was black flagged - thankfully late in the day.
On quiet it's definitely louder than stock.
I don't like the loud sound, it's just loud and doesn't sound good - way too boomy.
On quiet above 5k RPM it get's quite sweet. I hardly ever use loud at all.
By the sound of it, they don't all sound the same.

[GT6 Jonsey]

All good info gents cheers . Topgear have their 200 cell sports cats ( not X pipe )in production as they are currently out of stock. I have contacted Andy at Topgear and he thinks they will be ready in a few weeks. Reading horror stories of stuck/seized Lambda sensors I decided to poke my head under my yellow bd. Being a late .1 it has 4 flippin O2 sensors pre and post cat. Anyone replaced theirs recently ? The OEM Bosch ones seem twice the price of after market jobbies. Don’t mind paying the extra if it means no emissions warning lights on the dash