Geeky question/PSE advice

[GGibbo]

I've had a 987.2 s for about 4 months now, and am looking forward to using it over the summer.However, although it has virtually all the options I'd want, it doesn't have PSE.

his brings my first question- why does it make much more/a nicer noise when its been started from cold? I noticed it shortly after I picked it up; for the first 30 seconds or so(when on fast idle) it makes a lovely(ie loud) burble, but this dies away shortly.

This brings me on to the next question; has anyone got any tips regarding retorefitting PSE? Ive done a search on here, and found people that have formed groups to get the cost down, but would appreciate any other advice such as cost, quality of work as in can you tell its been retrofitted or just any other pointers.

Cheers

[gl20]

The extra noise on start-up is the same as with any car but more noticeable on your Boxster because i) more sporty exhaust, PSE or not ii) engine closer to you and iii) one cylinder head particularly close to you with less gubbins to muffle it because of the configuration (although iii is not relevant to the burble). Engine generally louder on any car at start up due to cold-start devide giving more revs and (this is where I might be wrong!) different resonance in the pipe simply because the exhaust temp will start off being lower.

The PSE exaggerates all this at any engine temp and does sound great. Am sure you are aware though that no power increase? Hope you're able to get a fair deal and - if not - it's not a huge deal imho. My previous Box didn't have one.

[hungry_hog]

I have a 996 with PSE and I noticed this as well. When you start the car from cold it roars like a lion having its testes removed. However if already warm it's more of a mouse squeak! However the sound when "pressing on" is the same whether cold or warm.

[mrdemon]

Vist Gert at carnewal.

[rigster2]

I know exactly what you mean regards the nicer noise on start up from cold.

There is definitely something that happens after about 20 seconds run time that numbs the noise.

Maybe there is something that makes the cat warm up quick to satisfy emmisions then reverts to normal when that is warm (after the 20 seconds?).

Does seem to be a flap closing somewhere though.

I too am looking at a retrofit for the PSE. Mine is a 2011 2.9 and have been quoted £1990 all in.

Cheers, Matt

[paulmoonraker]

rigster2 said:

I too am looking at a retrofit for the PSE. Mine is a 2011 2.9 and have been quoted £1990 all in.

Where? I was quoted 2.5K yesterday? The pricing seems somewhat random across the dealers... What's this 'visit Gert' option then?

[Zyp]

Gert at Carnewal can make your existing exhaust into a PSE-a-like for a fraction of the cost, apparently.

[GGibbo]

If there's a few people looking at a retrofit then put the word out- I think there are group but savings to fe had from OPCs. Good idea on the test drive of a pse car beforehand as well

[RiccardoG]

I have a 997 but am pretty much in the same boat. Have owned it a couple of months now and the key missing factor is a bit more roar.

The cheapest way is to do the "Gundo hack" (look it up on Google). This will keep al the existing hardware but bypass with a weld certain part of the exhaust. Basically it turns the exhaust into permanent PSE 'sport' mode. The drawback, for me, is that it will always be noisy. Cost shouldn't be more than £300.

The key advantage with the PSE is that it has electrically controlled valves thus enabling it to sound loud or not.

Have a look at this for more info on the Carnewal option (on Caymans):
http://www.planet-9.com/united-kingdom-ireland-reg...

[Slackster]

I just got quoted £2450 ex VAT at OPC sheffield to have PSE fitted to my 07 Cayman S. ( thats with £500 discount )

was told its a 5hr job and since I dont have the chrono pack installed and thats where the extra cost is as the wires that are laid when that is fitted are also used as part of the PSE install... Ouch..

will probably be going to see Gert now instead

[Ian_UK1]

GGibbo said:

....This brings my first question- why does it make much more/a nicer noise when its been started from cold? I noticed it shortly after I picked it up; for the first 30 seconds or so(when on fast idle) it makes a lovely(ie loud) burble, but this dies away shortly.....

Cheers

This is caused by the cold-start / catalyser heat-up programmingin the ECU. Please see below from the Porsche Tech manual:

Starting phase of DFI engines with high-pressure stratified charge injection
High-pressure stratified charge injection is used in the DFI flat-six engines in order to
optimise cold starting with regard to fuel consumption and emissions. In this process,
fuel is injected once into the specially shaped piston recess just prior to the end
of the compression stroke when the engine is being started. This forms a stratified
charge around the spark plug to ensure that an ignitable mixture is formed.
This reduces both the amount of fuel required and the emissions during the starting
phase compared to intake manifold injection.

Catalytic-converter heating phase of DFI engines with dual injection
Once the high-pressure stratified charge injection starts the engine, the engine management
system switches to the catalytic converter heating phase. In this operating
state, multiple injection helps to bring the catalytic converter to the temperature
required for optimal conversion of pollutants as quickly as possible.
To this end, the first injection of fuel takes place during the intake stroke and the
second injection of fuel occurs into the piston recess when the intake valves are
closed, just before the end of the compression stroke. The slightly lean air/fuel mixture
(lambda value approx. 1.05) can then be ignited at a very late point, thus
increasing the exhaust temperature. The resulting delayed combustion and the continued
exothermic oxidation of unburnt fuel (excess oxygen) even after the exhaust
valves are opened produce a considerably higher exhaust temperature directly with
the use of dual injection to heat the catalytic converters.
The high exhaust temperature quickly heats the catalytic converters to the temperature
for optimal conversion of pollutants. As a result, emissions during the warm-up
phase are significantly reduced and the secondary air pumps are no longer required
for all engines.

What you are hearing is the effect of a lean mixture being ignited very late. The moment that the exhaust goes quiet after about a minute from starup marks the end of the catalyser heating phase and the ECU switching to normal mapping.

[Actus Reus]

As a quick aside (and without searching) how does the Carnewal mod work with a Porsche warranty?

[Ian_UK1]

Actus Reus said:

As a quick aside (and without searching) how does the Carnewal mod work with a Porsche warranty?

I have Gert's RSR silencers on my '7S.2. They're modified entirely inside the cans so there's no immediate external evidence that any mod has taken place. Once you look closer however, you'll notice the seam that bisects the whole can (where the 2 halves attach in production) is now beautifully welded rather than folded. I don't know if this is the same for the Boxster.

Whether the average Porsche tech would notice, I've no idea!

As an aside, I kept my original silencers just in case (and bought another pair for less than £100 off Ebay to trade-in for the RSRs). Swapping the whole exhaust on my car, including the centre-silencer bypass pipe, takes about 2 - 2 1/2 hours. This includes removing/replacing the rear lights, rear PU and heat shields - they come apart VERY easily and give you complete access to all the exhaust components on the 997.

Edited by Ian_UK1 on Tuesday 1st May 15:19

[telford_mike]

Zyp said:

Gert at Carnewal can make your existing exhaust into a PSE-a-like for a fraction of the cost, apparently.

I went to Gert's place last summer and had this done. Absolutely wonderful sound, and a nice weekend away!

[Actus Reus]

Thanks Ian - I must say I'm very very tempted. I can't use a spanner myself, nor do I have time to go to Belgium at the moment, but I might enquire locally about getting PSR to fit the new exhaust for me, and perhaps arrange to send the one from my car back to Gert - all I ever hear when this comes up are good things...

[Slackster]

Just bit the bullet and ordered a GT exhaust from Gert, expected next week! I then spoke to pecarspecialists who are 15mins from me and they say they can fit it for £50 so i'm all sorted.

Sod blowing £2500 with porsche for the same sound