3.4 stock exhaust cans...

I have a MY 2000 996 w/ Fabspeed exhaust. The PO installed the exhaust and it has resonance (sp?) between 2K and 3K. It's loud enough that it's hard to have a conversation with someone. I saw a mod on here where you take the OEM standard exhaust cans and convert them to the PSE w/out the switch. I was wanting to try it but don't have the origianal exhaust. Does anyone have there old exhaust laying around that they want to get rid of? Thanks in advance

Yup. The stock cans off my '99 C2 are sitting in the garage. You can have them if you want swing by. I'm in St. Louis as well.

Take the 3.6L cans. They are way easier to convert.

Mark - I have some already converted 3.4 mufflers - I put them on last weekend and they are too quiet for my taste...I put back on my GHLs.... https://rennlist.com/forums/showthre...ighlight=combo PM me if you are interested....

There is a serious misconception that this mod converts the cans to a PSE. They do NOT. They do however, improve the sound. If it is PSE you are looking for you will be disappointed. If you want a better exhaust note than standard, you will probably be satisfied.

I haven't done this myself, but plan on doing it. The acoustic model is identical (physical internal shape, material used, pipe size). So why do you think they are different ? The only time it can be different if someone uses a pipe of a diameter different than the PSE ver2 (from 2nd chamber to outlet).

It's not just me that "thinks" that. There is plenty of testimonials from board members about the "PSE" mod. As I have stated, it is an improved sound but if you are looking for a 1:1 PSE comparison match you will be let down.

Having done the mod.... I concur with LVDELL... But then again mine are '99 cans. I do like the results eventhough not PSE sounding.

I'm not for or against either arguement. But I find it hard to believe that there is some special "porsche blessing" on the PSE mufflers. When compared to the modded mufflers (modded in a certain manner, explained below) they are identical in all respects. Laws of physics. They have the same internal shape, same materials and same gas flow volumes. The only way they can be different is if People are calling ANY mod to the stock mufflers the "PSE mod". There are hundreds of ways you can mod the stock muffler (size of pipe, start/end point of that pipe etc). But the PSE is just one such a combination of those variables. Something I don't really know or haven't yet understood. As an engineer, given the data I cannot see why the performance would differ unless there is an important fact I'm not even aware about. I'm thinking the reason you find a lot of differences in the sound when comparing modded mufflers to the real PSE could be due to #1. Of course, if its #2, I'd love to know more about the differences. About the PSE mod. The 1st version of the real PSE was based off 3.4 L engine mufflers. There was a J style bypass pipe (3/8") from inlet to outlet. The 2nd version of the real PSE was based off 3.6L engine mufflers. They had a L shaped pipe from the 2nd chamber inlet to the outlet pipe. Basically you let the air pass thru the 1st chamber as usual but as it almost enters the 2nd chamber you bypass a part of that volume it out to the outlet. So some of it goes out and some of it goes thru the entire 2nd chamber and the entire 3rd chamber. How much of air passes thru each route is determined by how wide a pipe you use as the bypass. The real PSE's bypass pipe has the same diameter as it outlet pipe. Note that the 3.4L engine based mufflers and 3.6L engine based mufflers are different internally. So doing one mod on the other won't get you exact PSE sound. Finally, the real PSE also has a cut off (vacuum actuated) valve (open/closes bypass pipe) electronics to control that valve (when to let the vacuum in, when not to) So when the above two are working the acoutic model changes. So you basically switch between "stock muffler" and "PSE" dynamically on the fly (as determined by the electronics, based on your current speed) Most people doing the mod don't want such a cut off (i.e. PSE->Stock) zone. This is what keeps the mod simple, managable and less prone to "manufacturing" errors. If they actually want such a cut off, it becomes a very complicated mod, and you're better off getting the PSE. The fact is that a lot of people installing the real PSE keep the mufflers in "always PSE" mode by cheating the electronics or cheating the vacuum valve. Hope that helps ! Cheers ! Sid

Converting the 3.6 mufflers that have the recessed nipple by installing the bypass pipe is as true a PSE (full time) as it would be coming from Porsche. Same mufflers.

Believe whatever you want to believe. Swing by my place and we will compare. I'd love to be proven wrong , but I just don't see it happening.

I this this mod about 2 months ago, on 99 cans.. did not spent much money ($200), but on the other hand, did not get the sound I expected...it is just too soft, can barely hear the difference.. If I had to do it again, will get Dansk of PSE.. would not this mod again, no matter how inexpensive it is.. just my opinion...

I have performed the PSE mod to both 99 and 2002 cans. I can say that they are a night and day difference from each other. Though the 99 cans did sound deeper and sportier than stock, they sounded no where near PSE. Last weekend, a buddy gave me his 2002 cans so I did the PSE mod to them. I had to find out...are '02 cans really that different? Externally they look almost identical. Just finished installing them. All I can say is WOWWWWWW.... They sound tremendous! Dare I say very close to PSE?.....absolutely! I'm gonna have to compare to my buddies real PSE this weekend. Feel free to throw the "I told you so" messages my way. I'll try to post a video this weekend.

I told you so.

I did this mod to 3.4L cans. While the sound is deeper and a little louder, I was a little disappointed that they were not a lot louder. I still have my OEM stock 3.6 L cans, but don't want to "hack" them because I am leasing the car and may not buy it at lease end. Unfortunately, I have yet to hear PSE mufflers in person, so I don't really know what I am missing. 87turbolook911 - you are the only person I am aware of that has done this to both the 3.4L and 3.6L mufflers. After you have had a chance to compare your 3.6L exhaust sound to your buddy's PSE sound, if you could post your thoughts along with the video comparison, it would be GREATLY appreciated.

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

I think I'm going to just drill a hole in the muffler inlet pipe while I'm waiting for my 3.6 cans. Then I will throw these in the trash as they will have been hacked to pieces. The good news is that my old cans will sound better while I wait! Can anyone tell me if there's a downside to doing this temporarily? Of course the exhaust fumes will be coming out the small hole, but if it's only for a few weeks - any harm done?

Can't tell you about any downside of the drilling you mention, but I ended up with stock 3.4 cans. I had the local muffler shop fabricate some bypass pipes and though it was "cool", I could only take it for about 3 weeks. I guess if I was really gung ho, I would deal with it, but after a few 3 hour rides, well, I started developing headaches. It also made my interior buzz and rattle all over the place. I decided against modifying the 3.4 cans based on consensus: almost no difference at all. I guess I could get a set of 3.6 cans and mod them, but at that price level, might as well buy something already proven (Fabspeed, Tubi, etc.). Now onto putting that orange cap on my intake! HA!

After reading this discussion thread, I'm thinking I'd like to try the "PSE sound" with a set of converted 3.6L mufflers "with the nipple indentation (whatever that is). Anyone have a set they'd be willing to sell me at a reasonable price? It seems that this might be a way to get some pleasant sound without the price tag of a PSE system. I'd like to hear from you if you have a set sitting around after a muffler mod. Chuck

Does this mean you are selling your Fabspeed mufflers? If so, I am interested.

OK Guys, My problem is pretty simple vs what you all seem to be dealing with. My 2000 C2 (3.4L)with factory PSE operating is to loud, raspy and "raucous" for my taste. I have bypassed the vacuum switch so the bypass pipes stay closed (Quieter). This is fine; now I can hear all the wonderful sounds a Porsche drive train makes. The trouble is, around 3000 RPM there is a low frequency rattle/resonance that is very trashy-sounding. Loose Baffles? Maybe, but it doesn't sound like a real metallic rattle. Sure, a mellower note would be nice but how do I get there without the obnoxious noise of PSE? 3.6 non-PSE cans? Sounds like everybody wants these to mod them.... jVm

Not really sure when the car was purchase new, but exhaust systems have 7 year warranty. Maybe you can take it in to have it looked at. Just did the 3.6 mod and have none of the problems you describe above. It just sings. I say try finding 3.6 cans and mod them. Like Tim has said the mod is about 80% of what OEM PSE sound like. Note. (I have never heard OEM PSE), but I think it would be to much for my taste.

JVictor, I can virtually guarantee that if you want to trade your '02 PSE for the '02 stock cans, you will find a "taker". However, it sounds like your PSE is not functioning properly. When I turn my PSE "off" it stays "off" and it sounds identical to my old stock '02 "cans". I'd say a trip to your dealer (to diagnose the problem) is in order.

Hi Guys, Thanks for the imput. Any more out there appreciated, too. RayS, mine's a 2000, not an '02 . I think later models do have an "off" switch. Mine does not. Vacuum, via an under-bonnet switch (controlled off the DME?), holds the dashpots on the bypass pipes closed (these are the early PSE where smaller 3/4" bypass pipes go from inlet to outlet). Simply by re-configuring the 1/8" plastic vacuum tubes I can apply constant vacuum to the dashpots and the PSE does not operate. "Evansaero"; thanks, I never thot of the 7-year warranty. I think I'll talk to the dealer and have them listen to it. It seems I have read here that these older cans tend to have baffle problems? jVm

This thread is kind of old...after reading the responses and considering my options, i decided to keep the Fabspeed (about 10 months ago ). It didn't take long before i really started liking it.

I have a base 997. 3.6. I wonder if i can perfrom this mod on my exhaust. from what i understand the 997 exhaust is redisigned? and the pse for 997 has 2 seprate exhaust pipes, i wonder if you can combine them to one like you guys have done it. thanks in advance

Just one more opiinion... I have an '02, and I did the mod myself using 2-1/4" stainless. I love the sound, especially at idle and under load. Exactly what I wanted... just a bit more snort without being obnoxious. 60 bucks (already have the tig welder) I did a before and after video and put in on utube, but the microphone wasn't sensitive enough to overcome wind noise and really show the true difference. But I would say if you want your car to sound a bit more raw and agressive, but not draw unnecessary attention, this or (the much more expensive) PSE mod is the way to go. But do it with 3.6L cans. If you 1) cut the holes as large as possible, and 2) use 2-1/4" tubing, I have a hard time accepting that it will not sound exactly like the PSE mod, though anyone who spent a couple grand on PSE will undoubtedly dispute that.

Yes, you should be able to do a similar mod to your 997 stock exhaust. In fact, about 18 months ago, a guy posted a pic of his modded 997 mufflers. Here is the pic. COmpart this one to the pic in the post above and you will see that the basic muffler design is very similar except that the exhaust pipe (to which the tips are attached) is longer on the 997 version. I have not heard how this modidified version of a 997 muffler sounds, but doing this mod will allow the exhaust to by-pass the third chamber in the muffler which should make the sound louger. I hope this helps.

Don't listen to Gota911. He talks you into doing all sorts of questionable mods....and you end up really liking them. At his suggestion I did the mods to the 3.6L mufflers....and they are aggressive but not obnoxious....they growl when you get on them, but are mild at a stoplight or when floating the pedal at cruising speeds. No resonance at all. Yep....watch out for Gota911!!

Chuck, isn't he the same guy that is always giving "Newbies" a hard time about not posting pics? Yeah, he is a real SOB!

CG - Are you going to give it a try?

where the heck do you get 2.25 stainless!! i cant find it anyhwere

I ordered from Burns Stainless ( www.burnsstainless.com ), type 304 stainless steel. Part code UB-225-40-16-304 (it's a U bend)

thanks.. ordering it up now... i have a '99 3.4 and got new 997 3.6 cans given to me!! awesome! cant wait!

i only need one right? and then i cut it in half?

Quotes source post: 5904772

Be careful. Installing 997 cans into an early 996 is not easy. Have a look at the pics on the last page of this thread: https://rennlist.com/forums/996-forum/460356-will-997-mufflers-fit-on-a-1999-996-a.html You might be better off finding some 996 3.6 cans. ....Rickker

im lookin for some used 3.6 cans also.

sorry to bump such an old thread, but i want to try this and do something slightly different. I've never taken the exhaust off my MY 2002 Carrera so I dont know if you have to remove all the pieces seperately(ie takes the tips off first, then the muffler, then the piece that connects to the cat pipes). But I want to run a pipe thats just like a fabspeed muffler bypass pipe, but very small in diameter. based on the picture in the thread above: i would like to weld a small diameter pipe from this pipe (right at the bend) to the tips.. i would imagine this would improve flow and add a pretty good growl. my only concern is that once this is done, can this entire piece be reinstalled at once, or do the pipes have to go in seperately like the muffler to the left of it in the image?

Hello I have a 996 in 2003, what do you recommend for the change to the discharge, the first version with the small tube, or the second version with the big tube? differences in sound? but with several modifications you lose performance?