So someone bumped my 991 Turbo at some point because I noticed my left exhaust outlet was pushed in more than it should have been. Bummer I thought
So I searched and found a new OEM unit and surprisingly enough it was ~$740 which got me thinking....anyway here is what the inside of the OEM one looks like


and a close-up



one more from another angle




Why does this Porsche muffler cost so little compared to all the aftermarket mufflers out there? They're thousands of dollars! Heck, even a couple of bent pipes to replace the space where the muffler was cost more than twice what this did. I'm not playing that game...I may tinker with the innards of this spare case and see what I come up with. Maybe something Ruf style with re-routed pipes instead of a chamber in the middle

 

I'm no engineer, but it sure looks like you could weld an X-pipe and remove part of the cover for weight savings and have your own lightweight custom exhaust

 

If you walked into a Porsche dealer today and wanted to buy a new original exhaust system for the 991 turbo, the cost would be $5525. On the used market they're not worth nearly as much, simply because there isn't much demand for them.

Comparatively, most aftermarket systems are between $4000-$5000, and offer weight savings, better performance, and MUCH better sound. In most cases, they're a bargain compared to OEM.

 

That's exactly what immediately jumped out at me. With such a big case it wouldn't be hard. I have a bunch of exhaust donuts for just such experimentation. The devil is in the details though I suspect, but it wouldn't be too hard

And a turbo back exhaust from the dealer being $5000 I understand because of the catalytic converters but a catback 'exhaust' is what I'm talking about. A lot of guys want to keep the stock tips so that leaves $1600-5000 for a couple of muffler cases and pipe or just pipe and that seems off to me. Like there is a disconnect somewhere

 

Ah good point, I'd have the check how much just the muffler is, but I'm guessing the cats are the expensive part.

 

Love to see photos of what you come up with. I think the stock muffler sounds pretty decent with a set of cat delete pipes. Maybe some stock vs. modified stock vs. AM muffler testing is in order.

 

I went through this on my Cayenne TTS when my wife dinged the rear bumper and messed up the right side of the exhaust. The new tip and muffler were a total of $1800. So I paid $3200 and got secondary cat delete pipes, tips and the performance exhaust plus a BMC filter from Fabspeed. I consider the extra $1400 money well spent because the car sounds better and you can feel the exhaust and in sport mode it's really throaty. Not a lot louder but you can feel and hear the difference, plus I like the Fabspeed tips. I am a fan of aftermarket exhausts. I have them on both of my Porsches and I put one on my M5, haven't been disappointed yet. I have heard several different 991TTS aftermarket exhausts in person and I think they are all good and definitely better than stock. Now the exhausts for the 991 are fairly high but I think that most of them are well built and probably you are getting what you pay for.

JMO.....

 

I don't care about price. The OEM exhaust sounds so lousy. Like a freaking leaf blower. So unbefitting such a fast car. When I took my Tubi catless to my dealer the entire sales staff gathered around it and asked me to rev it up. The general sales manager of the dealer proclaimed to the staff that this is the way Porsche should have made the exhaust sound from the factory for the car.

 

The M5 had the same problem. I think it's more the turbos than anything else. I have heard the C2S with the Porsche sport exhaust option and it sounds better because of the NA. That's a 400hp engine with a sport exhaust that sounds louder than the Turbo. This is why the Turbo needs a more aggressive exhaust from the factory, the C2S shouldn't sound better.

 

Mr. RMDZidane,


I like your approach. I have access to a fab shop who often fabricate exhausts for various models (domestic or imports).

We took a look at your pics and we decided to simply cut out the CATS (where most of the restriction is) and then see how it sounds. At that point, if we need to dig deeper, then perhaps we will weld up an X-crossover inside to connect the internal pipes.

We think this approach will work. Granted, if you delete cats then will need to turn off...no biggie.

This would save me thousands vs. buying an aftermarket unit - chances are it will perform just the same.


Stay tune

 

Of course there are louder systems out there that flow better. That's very easy to do. I'm just not into the price charged for those exhausts. I think it's strange that in this cars case OEM is so much less expensive. Porsche has to deal with all of the EU/TUV regulations dealing with sound/emissions quality, along with the U.S regs so that's a lot of certification expenses that most aftermarket guys don't have to deal with so it stands to reason that there should be savings passed to the enthusiast who buys an aftermarket catback exhaust that sounds 'better' and flows more....which I say again is very easy to do with any turbo car. Especially a rear engine vehicle with such a short exhaust run. Replace the catalytic converters from the cost equation with straight pipe and it is really easy.
As for modifying the stock muffler: It's a bit more than an X connector because one exhaust pipe flows to two outlets in the chamber so there would have to be a rounded turn from the incoming exhaust pipe to the outlet which would then branch to the two exhaust outlets so that the two 'x' pipes wouldn't run into each other. I like this because it keeps a relatively straight shot instead of any 180's because i think that's ludicrous to have in any exhaust system meant to flow. I personally like the Sharkwerks catback exhaust for this reason I just don't like the price.

 

It's the Porsche tax, plain and simple. As the car goes up in price, so does the price for aftermarket parts. That's why I still have factory exhaust on mine.

 

Hi E-Gear did you a set of decat pipes on the standard backbox/muffler in the end?

In the end what was the gains/performance if any?

thanks

 

E-Gear, RMDZidane

Any update on this project as am thinking if fabricating some decats meself and fit them to the standard muffler and note the follwing:

1.) Noise diffence on idle and WOT

2.) Performance gain if any and ideally logging with a Vbox

3.) Stage 2 Map and see and once if any gains and try to compare these with timings with other stage 2 cars that have aftermarket exhausts fitted

Bearing in mind i've got a Cargraphic X Pipe/Silenecer Replacement which is believe is a 2.5" system that i can easily fit but i don't mind trying the above project at the same time lol

So any advise/tips/support would be appreciated

 

RMDZidane

I also have a 991 Turbo which replaced my 997 GTS that I fitted a SharkWerks 997S muffler bypass system ($895) which sounded awesome. I'd love to have the same for my Turbo but I agree the cost is a bit high. I also would be curious if you're successful with an x-pipe in the OEM muffler box.