Cats/ Muffler/ Bypass. What's the difference?
 

Hello all,
I don't know what the difference between the above 3 components. If I want some lower/deeper exhaust tone, which one of those three compenent should I replace? Some says do only the muffler, while others say keep the oem muffler, and replace the cats. Others mentioned about the bypass.

Im clueless. Pls advice!!

i wouldnt recommend the exhaust bypass.

since u r clueless (ur words :)) and only want lower/deeper exhaust tone

i would advise u to do a 'Gundo hack' and call it a day.

do a search for 'gundo' and u will get tons of threads.

this is the one started by the man himself

https://www.6speedonline.com/forums/...ste-money.html

BOL

Very interesting thread. thank you! I think I'll just stick with getting a Cargraphic muffler for now. For a vehicle near $100k new, I don't want to "mickey-mouse" w/ doing a cheap job at the muffler shop. :D

maxboy....here is something to help you out.

Cats are the government mandated catilitic converters that are right after the headers....3 small pipes coming out of the engine that merge into 1 larger pipe.

Mufflers are just that...the big boxes on each side behind the rear wheels that actually muffle down the sound.

By pass can be 2 things...a cat by pass or muffler by pass.

For a deeper tone all you need to do is just change out the mufflers. However different mufflers will make different sounds. I have Tubi mufflers on my car and they are more Euro and raspy sounding. Porsche Sport Exhaust and the so called Gundo hack sounds more raspy. Fabspeed, Borla and AWE have a deeper tone. I had Fabspeed on my 2006 and 07 and they were very nice well built mufflers. Cargraphic sound falls in between...very Euro with some rasp but a little more throaty than Tubi, PSE or the Gundo hack.

Hope this helps...welcome to the board too.

mdrums,
thanks you for clarifying! my Porsche is still a virgin, so I'm compiling a list of things I want to do with it. haha.

That is a slippery slope that many of us have gone down!

Let the modding begin.

i was just trying to help u buddy;)

even if u do not understand the dynamics of engine exhaust system, u should know that a muffler is merely a 'muffler' - its function is to reduce the engine exhaust noise.

'gundo hack' just alters the sound to simulate the PSE sound.

u can spend $1500-$2300 of ur (?) hard-earned money for a set of muffler

or do a Gundo hack.. ur choice.


cat = catalytic converter

basically it makes the bad emission gas (:) just sounds funny) not-so-bad... and also reduces noise.

changing to free-flow cat will yield the most power and make ur car sound like race car.. even from a mile away


FYI i have the Cargraphics muffler hilarious

Maxboy, the absolute best mod is to do a few DE's (drivers ed track events) or go to the Porsche Sport Driving School at Barber Motorsports Park in Birmingham AL...more if on the Porsche web site.
Moding the driver 1st is the best mod you will make and money well spent that you can use over and over after the car is gone and you are into your next car.

anyone know if its possible to do the gundo hack on an 09 S?

The complete exhaust system is made up of exhaust headers that lead to catalytic converters then end at exhaust mufflers. A muffler bypass deletes the mufflers from the system. I've done all of these at some point.

Adding aftermarket Cats: better sound; more hp; small weight reduction

Adding aftermarket Mufflers: better sound; more hp; moderate weight reduction

Adding Muffler Bypass: racecar-like sound; better top end; worse bottom end; significant weight reduction. Forget listening to the radio or having a conversation while driving!

It is possible. However, results are not as pleasing as the gundo hack on the 997.1 cars. you need to at least delete the center muffler along with the gundo hack on the 997.2 to get closer to the results on the 997.1

It has been done - someone even posted a vid/soundclip of the after. Search for Gundo hack and look for threads started w/in the last year and you'll likely find.

:)

Here is my car with the hack done. stock center muffler.

http://www.vimeo.com/8032859

Take a look at this picture for reference. The section that you see in between the tips is the cat-section. What you see to the right and left of the tips (looks like behind the tips in this pic), kind of tucked away behind the car's sheet metal, is the mufflers. There are two types of "bypass". One type bypasses the cat sections or basically just eliminates the cats leaving strictly piping in their place. Another type of bypass eliminates the two side mufflers.

If you're looking for a lower/deeper exhaust tone, my suggestion would be to replace the OEM mufflers with something like the Cargraphic muffler setup. They typically produce a deeper more aggressive tone then some of the other options out there. If you're looking to add more volume (and I mean quite a bit of it), then I'd also replace the factory cats with a good aftermarket 200cel cat setup, like AWE's.

I'm generally not a fan of any kind of bypass, as they generally just make the car LOUD, and do very little in terms of performance or creating a refined sound. Remember, the restrictive parts of the exhaust system, specifically the cats and mufflers, are what create the sound. Eliminating either one of them altogether will certainly make the car louder, but it's not always a good loud. You need those mufflers and cats in there to really create the sound.

http://farm5.static.flickr.com/4040/...90d297ef_b.jpg