Boxster/Cayman GTS Exhaustvalve 6500 rpm PSE?

Boxster/Cayman GTS Exhaustvalve 6500 rpm PSE?

Author
Discussion

HosonAndersson

Original Poster:

7 posts

113 months

Sunday 15th March 2015
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Just bought myself a Boxster GTS and discovered that when your have the Sports exhaust activated it´s like it is opening its valves at 6500 rpm.. The exhaust just explodes. Sounds like when a GT3 opens up in sportmode. Is it anybody who knows more about how the PSE works?


dreamcar

1,067 posts

112 months

Monday 16th March 2015
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Possibly the engine management altering the valve lift than anything on the PSE. Mine is still running in and trying very hard to keep the revs to 4,500 rpm. I notice the note hardens at just the time I have to change up - can't wait for the running in period to end! Love the fierce bark when changing down manually in sport or sport plus, even at comparatively modest revs!!

bcr5784

7,115 posts

146 months

Monday 16th March 2015
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HosonAndersson said:
Just bought myself a Boxster GTS and discovered that when your have the Sports exhaust activated it´s like it is opening its valves at 6500 rpm.. The exhaust just explodes. Sounds like when a GT3 opens up in sportmode. Is it anybody who knows more about how the PSE works?
PSE (activated) works in two ways. There are valves in each half of the exhaust which change the exhaust silencing when activated (make it louder). The valves are "enabled" by the dashboard switch and actually open/close depending the engine vacuum.

Secondly - in order to create the pops and bangs on lift off, Porsche cause unburnt fuel to enter the exhaust where it explodes in contact with the hot manifold. In days of old this used to occur because of poor carburation (either too rich or too weak mixture) but these days it does not, and need not, occur because fuel injection systems normally do a much better job - and on lift off fuel is normally cut off completely for economy reasons, so there isn't any unburnt fuel to get into the exhaust system.

Some associate this second effect with what a sports car should sound like, others like myself think it odd that a deliberate malfunction should be viewed in that way. It has been a controversial subject on this forum which has aroused strong passions, so I'll leave it at that.

koorby

175 posts

147 months

Monday 16th March 2015
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Oh dear... bcr chimes in with his BS about how PSE is so bad. Predictable.

bcr5784

7,115 posts

146 months

Monday 16th March 2015
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koorby said:
Oh dear... bcr chimes in with his BS about how PSE is so bad. Predictable.
If this is BS explain what is technically incorrect or even unbalanced about what I ACTUALLY WROTE. Either CONTRIBUTE some information or shut up.

m999psw

266 posts

199 months

Monday 16th March 2015
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The pops and bangs are created rather than just there as in the past, but it sounds great and is a bit of fun. If I feel like being quiet I have the choice with a switch and if I were really worried about that little bit of fuel used to make the pops and bangs and fuel economy I wouldn't of spent 70K on what is a fun weekend toy.


Budweiser

1,081 posts

185 months

Monday 16th March 2015
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bcr5784 said:
If this is BS explain what is technically incorrect or even unbalanced about what I ACTUALLY WROTE. Either CONTRIBUTE some information or shut up.
All you say is totally correct and I respect your dislike of this method. I really love the sound it creates end of.

It's healthy we don't all agree :-))

bcr5784

7,115 posts

146 months

Monday 16th March 2015
quotequote all
Budweiser said:
All you say is totally correct and I respect your dislike of this method. I really love the sound it creates end of.

It's healthy we don't all agree :-))
Thank goodness we can sensibly disagree.

corvettedave

274 posts

158 months

Monday 16th March 2015
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bcr5784 said:
Thank goodness we can sensibly disagree.
Oh jesus its the engineering god again

out of interest engineering god, i have a 2007 cayman S, doesn't have any sports mode, no sport buttons etc, which means no pops, bangs, crackles etc, so on Saturday, local garage put on a aftermarket cat back exhaust system for me, and guess what Ive now got loads of pops, bangs and crackles, but hang on Porsche didn't program this stuff into the ecu on this model, so???

bcr5784

7,115 posts

146 months

Monday 16th March 2015
quotequote all
corvettedave said:
Oh jesus its the engineering god again

out of interest engineering god, i have a 2007 cayman S, doesn't have any sports mode, no sport buttons etc, which means no pops, bangs, crackles etc, so on Saturday, local garage put on a aftermarket cat back exhaust system for me, and guess what Ive now got loads of pops, bangs and crackles, but hang on Porsche didn't program this stuff into the ecu on this model, so???
The exhaust has cocked up the fuelling, as you might expect! It's really not rocket science. You need to get the ecu reprogrammed.

corvettedave

274 posts

158 months

Monday 16th March 2015
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you are completely wrong my old fellow!

i still have the factory headers with down pipe and cat on the car, and guess where the o2 sensors are, yep there's one on the down pipe for the ecu to monitor fueling and other is after the cat, which is before my new exhaust, that one is to monitor emissions st

so now what genius?


koorby

175 posts

147 months

Tuesday 17th March 2015
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bcr5784 said:
If this is BS explain what is technically incorrect or even unbalanced about what I ACTUALLY WROTE. Either CONTRIBUTE some information or shut up.
The information I am contributing is conveying the message to you that everyone is sick of your anti-PSE bias and it's becoming quite tedious and annoying to see topics being hijacked by you these days.

Given that PSE on the GTS is one of the major reasons people here have bought the car, can I ask that you please get off your soapbox and shut the hell up about the supposed engineering bdisation in it.

bcr5784

7,115 posts

146 months

Tuesday 17th March 2015
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koorby said:
The information I am contributing is conveying the message to you that everyone is sick of your anti-PSE bias and it's becoming quite tedious and annoying to see topics being hijacked by you these days.

Given that PSE on the GTS is one of the major reasons people here have bought the car, can I ask that you please get off your soapbox and shut the hell up about the supposed engineering bdisation in it.
Look at the original post - a guy asked a question, no-one replied for days so I answered it correctly and mildly in the hope that non of you lot would get abusive - some hope.

bcr5784

7,115 posts

146 months

Tuesday 17th March 2015
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corvettedave said:
you are completely wrong my old fellow!

i still have the factory headers with down pipe and cat on the car, and guess where the o2 sensors are, yep there's one on the down pipe for the ecu to monitor fueling and other is after the cat, which is before my new exhaust, that one is to monitor emissions st

so now what genius?
If you are getting neat fuel in your exhaust causing pops and bangs (which you didn't have before), then ergo your exhaust is the cause and has interfered with the fuelling. It's simple cause and effect. But I can't be bothered arguing further - if you like it that way then fine.

Dr S

4,997 posts

227 months

Tuesday 17th March 2015
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Maybe I am lacking the history of this emotional debate but I don't see anything bad in bcr's comments. I found them interesting as I was not aware that the pops and crackles were an "engineered malfunction" for aural pleasure. Whether you like it nor not is purely a matter of personal taste.

To me it sounds good but feels a bit at odds with the highly engineered cars that generate it. I prefer the effect of the sport buttons in my GT3/RSs.

dreamcar

1,067 posts

112 months

Tuesday 17th March 2015
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Dr S said:
Maybe I am lacking the history of this emotional debate but I don't see anything bad in bcr's comments. I found them interesting as I was not aware that the pops and crackles were an "engineered malfunction" for aural pleasure. Whether you like it nor not is purely a matter of personal taste.....
.
Neither do I. I happen to disagree with him also and quite like the pops and backfires, it adds to the car's emotive character so often lacking in today's cars. All bcr said on this thread (even if maybe he went a bit OTT with his criticism on another thread which wound some up) was that the sound wasn't for him, to be greeted by all the keyboard warriors jumping down his throat.

Seems there are some pretty short fused contributors on PH which to me detracts from the forum's quality.

dreamcar

1,067 posts

112 months

Tuesday 17th March 2015
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On a side issue with PSE I believe the new EU noise regulations coming into force in 2016 will kill the sound of cars such as the Boxster / Cayman GTS - enjoy whilst you can. 981/2 Boxster / Cayman may well have turbo flat fours anyway, recent Porsche model history has seen new engines introduced in the model half life refresh.

Trotmant

385 posts

115 months

Tuesday 17th March 2015
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We should revisit this thread when the pot4's arrive. Then we will be talk much more about synthesising of a PSE through speakers no doubt. So glad I bought a 981 GTS whilst I could. Last of a dying breed

dreamcar

1,067 posts

112 months

Tuesday 17th March 2015
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Trotmant said:
We should revisit this thread when the pot4's arrive. Then we will be talk much more about synthesising of a PSE through speakers no doubt. So glad I bought a 981 GTS whilst I could. Last of a dying breed
Totally agree! The 2016 EU noise regulations, ever more demand on corporate CO2 emissions (which can only achieved by high efficiency turbo engines) all signals that the current generation of cars will be the last wonderful, evocative sports cars.

bcr5784

7,115 posts

146 months

Tuesday 17th March 2015
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Trotmant said:
We should revisit this thread when the pot4's arrive. Then we will be talk much more about synthesising of a PSE through speakers no doubt.
I agree, but I think it but it will be all-but impossible to get a sensible discussion given the emotion on this issue.