Hi, I know it sounds unusual but I need to lose 3db temporarily for my US car (997 with original exhaust) to pass EU standards. Do anyone know a muffler or something I can adapt that would not risk damaging the engine. Do you have an address somewhere around Geneva Switzerland? Tks. P

 

You need quieter than stock ? Maybe some silencer tips ?

 

Yes please. I need 3db lower than stock for a day, to pass a stupid test and get the paperwork done. Needless to say, I'll remove it afterwards. The pb is that if I don't let enough through the exhaust I risk damaging the engine. Do you know any accessory provider who can help please?

 

FVD sells TUV cerified mufflers which meet EU sound standards and they sell sport sound mufflers which do not meet TUV spec. I have the sound version and i love them.

FVD OE Sound

They are not cheap though and i doubt you would want them just to pass a test.

Maybe add some stainless steel batting to the mufflers to quiet them down temporarily. Would probably be fine if you kept the revs down.

dr

 

Wow that is pretty strict- OEM mufflers are pretty quiet...

 

Can some steel wool be temporarily be stuffed into the mufflers which can easily be installed/removed and at little cost by a local muffler center?

Just a thought...

 

Steel wool is a great idea for this.

Also, you're not going to damage your engine by increasing exhaust backpressure. It may have less power, of may not even pass an exhaust gas emissions test though.

 

I think Techart makes an approved exhaust . You can check with CEC = site sponsor.

 

Why not swap your mufflers out for Euro stock mufflers? These by definition must pass Euro standards and there are literally thousands lying around at any European tuner for silly-cheap money.

 

Many thanks to all who replied and gave me some help. I will now check the vendors you mentioned.

Ian_UK1 please, do you think the muffler will suffice or are there other parts of the engine that are known to be different between US and EU cars that might have noise impact?
Do you know any address where to get a used genuine pair of silencers?
Thanks.


Kurt_OH: Glass wool is normally used around mufflers to contain noise within. Do you know anyone who stuffed the mufflers will glass wool?

All, have you heard of Cargraphics (Germany) exhaust systems? Any reference please?

Tks again for yr help. P

 

Quotes from Porshe's 'Technik' Manual on the 997S

'2633 Silencers

'2673 Pre-/main cat. converters
Two-stage catalytic converters (cascade catalytic converters) with pre- as well as main catalytic converters are employed worldwide.'

So it looks like only the mufflers/silencers are country specific. I'd imagine Europipe would have a lot of Euro-spec 997S silencers they've taken off 997S's and replaced with their (excellent) aftermarket system. There's a link to Europipe on the right hand side of this site.

 

Quick fix, old trick: take off your tips (a couple of screws), push a few inches of steel or glass wool into each exhaust, put a piece of 1/4" or 1/2" mesh inside the tip (so the wool won't blow out) before reinstalling the tips. Obviously the denser you pack the wool the more the noise reduction. $5 at a hardware store and you are done.

 

Tks for this. And you don't think it might damage the engine?

 

I'm not qualified to answer, but I can't think of any negative impact, especially during the short time you'd have this in your pipes. For some inexplicable reason Porsche, with all it's great engineering, has pretty lousy exhaust manifolds and mufflers if a person is concerned with flow resistance (back pressure) and the related volumetric efficiency of the engine, so you aren't going to add very much to the 'problem' by a little further obstructing the process at the *** end of the exhaust system. What we're doing is reducing sound pressure (noise or dB), which I'm sure is related to but not the same as flow volume.

 

I doubt it would damage anything but it will certainly demonstrate the effects an exhaust system has on an engine's performance.

It will certainly quieten down the car, will have little effect on performance at part throttle/low-to-medium rpms. Full throttle, it will feel like a couple of cylinders have been removed!!

So a good, cheap idea if you don't want to go particularly fast....