Tim.....as soon as we meet up again, I will let you take in all the PSE you want

 

87turbolook911:

I want to do this to my car (3.4L), but I am not sure where to make the connections on the "bypass pipe". I want it as loud as possible, so I am guessing I need as wide of a pipe as I can get to fit. I know that one end of this pipe needs to be welded onto the pipe that finally end at the exhaust tips, but where it gets unclear to me is where does the other end hook up to? Is it to the pipe that comes from the cat converter, or is it to the muffler itself where there is what appears to be a welded cap? I have noticed that on 3.6L mufflers, this looks like a nipple that sticks out, but on my 3.4L muffler, instead of a portruding nipple, its a recessed opening (think lid on a 55 gallon fuel drum). Any and every picture you could share with me would be greatly appreciated.

I removed my mufflers and ran it for a few minutes with nothing on it (yeap, not even muffler bypass pipes) and thought I love the sound, the resonance it a bit too much and not sure if it would get old too soon. Stock is just too quiet and investing hundreds of dollars on a new muffler is not an option right now..

Thanks.

 

Gus - you are correct in what you said above concerning connecting the "new" pipe from teh "cap" to the exhaust pipe. here is a pic of the stock muffler (on the right) from my '04 996 and a "modded" muffler (on the left). Hope this helps.

Let me know if you have any questions.

 

Thank you veryt much Tim! Any difference between doing it your way and doing the "bypass" from the exhaust pipe to the "catalytic" pipe? I want to make sure that I get the loudest sound from this mod.

 

Connecting a "J" shaped pipe between the cat pipe and the exhaust pipe is the "old" way of making PSE, as shown in the first pic. BTW - the mufflers in the 1st pic are NOT true PSE, they are stock mufflers "modded" to PSE. The latest version for PSE on a 996 is shown in the second pic (actual PSE mufflers). This is why there are two different versions of the "stock mufflers modded to PSE."

I don't know which version of this mod will be louder, because I have not heard how the "J" pipe mod sounds. However, some have reported that modding the 3.6L (2002 - 2004) mufflers will be louder than modding the 3.4L (1999 - 2001) mufflers.

 

OK, the latest version is the one I am going to go for if this muffler bypass proves to be too much in the long run. Thanks for the clarification.

 

It looks like a '99-01 muffler on the left (no accordian on the pipe)

There is a HUGE difference between the '99-01 mufflers and '02-04 mufflers in terms of sound after the mod. Although they look just about identical externally.

Compared to my buddies OEM PSE, I would say my exhaust sounds about 90% similar to PSE...the OEM PSE being 10% louder.

Good luck!

 

Yes, you are correct. The Modded "cans" are '99-'01 mufflers (no accordian on the pipe). I got these for free and paid for the muffler shop to mod and ship the mufflers.

I am leasing the car and want to be able to return it to stock if I decide not to purchase it at lease end, which is why I haven't modded my original mufflers. I am currently looking for a set of 3.6L ('02 - '04) mufflers to mod into psudo-PSE mufflers.

 

My cans (1998 RoW C2) are definitely the ones without the "accordian". I am having some muffler bypass pipes fabricated locally to see if it eliminates some of the resonance and drone that comes from running the car with nothing at all after the cats. If it stays the same, then I am definitely going to modify my cans (3.4) with the large pipe that connects from the "nipple recess" to the exhaust tip pipe. Once again, thank you all for the clarifications and opinions.

 

Gus, If your are going to do the mod, then go with 3.6 cans....3.4 cans IMHO are not worth modding. The sound difference is too subtle.

 

Gus - I agree with turbolook that there is not much of a difference between stock 3.6 cans and the modded 3.4 cans. They are a little louder, but nowhere the near as loud or as throaty as PSE.

 

If I was in the States where parts are relatively cheap, trust me, I would. But living in a country with only a handful of 911s, having to pay close to 40% import duty, plus international shipping, plus customs person, well, what can I say, it adds up! Thing is, I was ready to sell my 996 (especially after driving a 997GT3), but the sound with no mufflers made me like it a hell lot more. I need to find the time to have someone locally do the muffler bypass pipes for me (or I have a "line" on a pair of used Fabspeed bypass pipes that I can pick up next month) and if that works out to be too loud, then I guess I will mod my 3.4 cans and if its still too quiet, well, I will beg for someone to mail me one of those infamous orange caps! If anyone has had a chance to drive a 997 GT3 (or at least hear it) with the Sport button selected, that sound is what I am after (I mean decibel wise, I know my car will NEVER sound like a GT3).

 

Hola Gus. If a set of used 3.6 mufflers is what will help you here, I have a used set with the original rectangular tips that I can sell you.

Hablamos.


Theo

 

Gus, I don't know about the 3.4L cans but I did the 3.6L cans mod and LOVE it.

As you might know, Porsche had the PSE for 3.4L engines (version 1) and then updated the PSE for 3.6L engines (version 2, replacing version1 for all 996). Similarly there are 2 mods based off those two originals and they are quite different, mechanically ("J" vs "L" pipe) as well as acoustically.

Like I said, I'm really very happy with the 3.6L cans mod (on my 3.4L engine). And from what other board members have reported, the 3.4L mods have been kinda a let down. Do remember that ! If you still want to proceed with the 3.4L cans AND want a loud exhaust note try this variation to the 3.4L cans mod:

- use a larger diameter J pipe instead of the thin one show in the photo. The loudness of the sound volume (heard) is directly proportional to the volume of air going thru the by-pass pipe - so wider = more volume = louder.
- keep telling yourself that this is uncharted territory ! Acoustic results will vary. I don't _THINK_ you'll be frying your cats or anything bad (as long as all joints are well sealed etc) - but just think of this as an experiment !!

And finally PLEASE report back to us on how things went - we're curious !!

cheers and MOD on !
Sid

 

FYI about 3.4 vs 3.6 mufflers -

I did the MKII version 2 mod (2 1/4" pipe from bypass to outlet) on a set of 2000 (3.4) mufflers this weekend and for all the work, it barely got any louder or throatier - almost unnoticable. I'm waiting to receive some used 3.6s, and will post a follow-up when I've done the mod on them.

If you're thinking of doing the mod on 3.4 mufflers, and want a noticable sound difference - do the version 1 mod that connects the inlet directly to the outlet with the small pipe MKI, v1. Or get 3.6 cans like people in here suggest.

With my first experience modding 3.4s, I'd say the consensus is correct - something's different with the 3.6s that makes them louder.

Hope this helps someone.

Mike