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Congrats on your 991.2! You've got a lot of options here and you could easily end up spending money and getting too quiet of a result or too loud of a result.
Doing just the catalytic converter section alone on cars WITHOUT PSE may be end up with a disappointing result. PSE cars sound so great with the cats as they have almost a fully straight shot out of the PSE muffler when valves are open. Non-PSE cars never bypass the muffler so the end result of Sport Cats might be too quiet for some. It will up the volume a bit and add more turbo sound but do not expect the different to be night and day like on PSE cars.
A quick and cost effective way to yield more induction sound is a BMC air filter which will let you hear more intake and turbo sound. You could plan to do this when a filter change is due.
You could change out your rear exhaust section with something like our Performance Exhaust System. It will be on the aggressive side but it's IMO a proper amount for a sports car. When you change out the catalytic converters with this system that is when it can get very aggressive and induce cabin presence.
If you have any questions don't hesitate to reach out to us!
-Mike
__________________ SOUL PERFORMANCE PRODUCTS Quality Exhaust Solutions, Fair Pricing, and Outstanding Service
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A cat is an abbreviation for the word catalytic converter it is a key part in any exhaust system in terms of emissions, monitoring your vehicle, and performance. High flow cats are a specific kind of catalytic converter that are less restrictive and allow more air to flow freely through the exhaust. This ultimately allows you to create more power with the stock engine. More air in, more air out! X-pipes are another exhaust component that mergers the two separate exhaust coming from each side of the engine. This merge creates a vacuum within the X-pipe that pulls exhaust out of the exhaust chamber. (Again more air in more air out). Straight pipes is a word used for when there is nothing in the way of the pipe like a catalytic converter, x-pipe, or muffler. Please visit Fabspeed.com for all your exhaust needs or feel free to give us a call! We would love to chat and talk over the phone and explore options you could do to your 991.2!
Three basic components in the exhaust system that are muffling the noise: headers, cats, exhaust.
The stock headers are basically a plenum. All the flow goes into a big chamber, runs into a bunch of things before finding the hole in the side to make it to the turbo. Aftermarket tubular headers will clean up the sound, giving more distinct and crisp exhaust pulse sounds. Going with equal length headers, those exhaust pulse noises will be evenly spaced out giving the most GT3 -like sound as they use equal length headers along with basically every top-end performance car. Headers will only increase the noise level slightly. The stock headers are double wall stainless steel and the aftermarket tubular are single wall. So one less wall of material for sound insulation.
Catalytic converters have a woven core with different densities identified by a cell count. Basically the number of cells per a given area. I'd guess per square inch. Typical OEM cats are 600-cells and typical high flow cats are 200-cell which means they have bigger flow paths for less restriction. Those bigger flow paths also muffle the noise less. Changing the cats will increase the noise volume more than headers.
Exhaust and the types of mufflers. You have the most restrictive of the stock Porsche exhaust systems the the muffler having no straight-thru flow path option like the PSE exhaust. In terms of noise level, the quietest muffler has the exhaust flow go through it a couple times or a torturous path. A louder muffler would be a straight-thru flow and this is typical of aftermarket mufflers. The loudest is no muffler at all. With changing the exhaust section, it can create a constant drone at different rpm ranges. The OEMs use the mufflers to tune out the drone.
Suncoast Porsche will sell you a complete factory PSE for $3795 including the console switch. But installing it should be left to a pro. You also need to buy a new rear diffuser. I love my PSE.
So, your car has the dual "wide" split out tips and not the center exits. If you purchase the Porsche Sports Exhaust (PSE) system by Soul Performance from Zylinderkopfdichtung, ( https://rennlist.com/forums/market/1308016 ) It's nearly a $ 4,000 complete, bad *** set up he is selling for $ 1,900, But the exhaust tips exit from the center rear under your license plate and not on the outer, far sides of the car. You will need to purchase a new lower rear bumper cover (rear valance) that allows for the exhaust tips to exit center rear under your license plate. I would take your car to a good body shop and price the cost for a "Center Exit" Porsche Sports Exhaust bumper cover. You car will look like a brand new car.
It would look very cool and the entire job will cost less than buying all new components.
New exhaust options:
I have had both Soul Performance and FabSpeed on my past 911 cars. You'll be happy with either. Call them both with your "new exhaust" options and they will steer you in the right direction. Ask about a valved option as well. You will have the option to "turn on" and "off" the pretty noise
A factory PSE option from Suncoast will also be a good choice, You will have the factory Porsche valved system to turn on and off when you want by the push of a button on your center console, but you will need the lower "rear valance" swap out. They can help you with the proper parts you will need. Just find a proper shop to do the install
What’s a rear diffuser please?
also I agree. Can’t go wrong with Original.
Visit the Suncoast Porsche site and search out the parts for the swap. You can also call them and they can advise what a complete package will cost you see if they can provide a part numbers list.
As you may already know nothing Porsche will be cheap.
I learned something yesterday. The oem cats are approx 9 inches. If aftermarket cats are signifigantly smaller any gains are potentially offset by the smaller size despite the lower cell count. This is directly from someone who works with race teams. I almost made a 3k mistake on IPE's headers with 200 cell cats.
Originally Posted by spdracerut
Three basic components in the exhaust system that are muffling the noise: headers, cats, exhaust.
The stock headers are basically a plenum. All the flow goes into a big chamber, runs into a bunch of things before finding the hole in the side to make it to the turbo. Aftermarket tubular headers will clean up the sound, giving more distinct and crisp exhaust pulse sounds. Going with equal length headers, those exhaust pulse noises will be evenly spaced out giving the most GT3 -like sound as they use equal length headers along with basically every top-end performance car. Headers will only increase the noise level slightly. The stock headers are double wall stainless steel and the aftermarket tubular are single wall. So one less wall of material for sound insulation.
Catalytic converters have a woven core with different densities identified by a cell count. Basically the number of cells per a given area. I'd guess per square inch. Typical OEM cats are 600-cells and typical high flow cats are 200-cell which means they have bigger flow paths for less restriction. Those bigger flow paths also muffle the noise less. Changing the cats will increase the noise volume more than headers.
Exhaust and the types of mufflers. You have the most restrictive of the stock Porsche exhaust systems the the muffler having no straight-thru flow path option like the PSE exhaust. In terms of noise level, the quietest muffler has the exhaust flow go through it a couple times or a torturous path. A louder muffler would be a straight-thru flow and this is typical of aftermarket mufflers. The loudest is no muffler at all. With changing the exhaust section, it can create a constant drone at different rpm ranges. The OEMs use the mufflers to tune out the drone.
I learned something yesterday. The oem cats are approx 9 inches. If aftermarket cats are signifigantly smaller any gains are potentially offset by the smaller size despite the lower cell count. This is directly from someone who works with race teams. I almost made a 3k mistake on IPE's headers with 200 cell cats.
Slightly off topic. Any Idea what a dealer would charge to add the PSE Exhaust Kit from Sun Coast to my 991.1?
You're better off pricing the exhaust kit and install from the dealer you're thinking of using. Suncoast is just another dealer with a portal for parts sales. Your local dealer has the same resources for parts.
All in with indy doing the labor and dealer reprogramming new button $1500.
Suncoast and others will sell you parts you dont need. search pse parts list or im me.
Originally Posted by Live Steam
You're better off pricing the exhaust kit and install from the dealer you're thinking of using. Suncoast is just another dealer with a portal for parts sales. Your local dealer has the same resources for parts.
This shows an Akrapovic muffler and cats (the two cylinders at the each side) I bought the cats from him since I already have PSE from factory.
Given your limited budget it’s going to be hard to find a new muffler but you can probably find a used PSE or other brand mufflers. The Akra mufflers are $6,400 new but Akra is usually the priciest.
So look for a used set of mufflers first and if that doesn’t work then consider cats. You can find used SOUL or Akra cats for $1,500-2,000 and then have them installed. It’s a 2 hour job so maybe budget $300 for labor.
Quick overview of the terminology:Headers: Located above cats. They change the tone of sound. Makes it deeper or throatier.
Catalytic converters: These are located below the headers/turbos and before the muffler/exhaust. Aftermarket cats let more air pass through and less restriction creates a louder sound. SOUL & Akrapovic both have 200 cel options. I believe factory cats are 600 cel. Less cells = more air flow = better/louder sound.
Straight pipe: This option removes the cats altogether. This will trigger a an engine check light and will likely cause State inspection issues. The other negatives include the fact that it’s bad for the environment and you can smell fumes. Without PSE this will create a lot of drone as well.
Exhaust: This is your muffler. I have factory PSE and this gives me the ability to by pass the muffler and increase sound with a button which controls valves in the muffler. You can buy an aftermarket exhaust system with or without the valves. Some say you will notice drone with aftermarket exhaust systems and that’s why PSE is popular.
Brands:
Akrapovic
SOUL
Vektor
Sharkwerks
If you don’t care about drone and being loud in general then @Zylinderkopfdichtung setup is the way to go. Great price and value. If I didn’t have PSE I would have bought his setup instead of just getting cats.
If not keep checking Rennlist Marketplace and something will pop up eventually if you are patient. Good luck!
So a 991.1 with PSE really only needs headers and sport cats to enhance the sound? Any performance gains with these additions?
07-11-2022, 12:47 PM
