Kidasters

Hey Guys -

I did a search, and didn't really see an answer, so I'm starting a new thread.

Just got back into a 964, and I'm really happy with it. I had forgotten though how quiet they are compared to a 3.2 Carrera. Of course, my 3.2 wears a M&K one in/one out that is both lighter and louder than the stock muffler.

I was thinking of doing an exhaust modification to the 964, and I'm a little confused. So - it looks like Porsche added a secondary muffler after the primary muffler. So - my question to the group is, how do you plumb this now? Come off the cat and directly to the stock exhaust? Or do you need some type of crossover pipe and then hang the new muffler where the secondary hangs?

Thoughts, pictures and discussion please.

Tarek307

Personally i think 964 sounds best with stock exhaust + Primary Muffler Bypass , Currently i have one with B&B full exhaust system and headers, sounds great, but to me doesn't sound like a 964, i love the original 964 sound

Altex121

makoshark72

I just installed a primary muffler bypass, and I have the J pipe to bypass the secondary...I run the stock cat..

I also feel the stock system is too quiet...

Which component of the 3 most affects TORQUE??

Thanks

Bigsix964

golfnutintib

there ARE good and clear posts on this subject

short answer

secondary bypass gives more midrange torque, deep burble, some weight reduction
primary bypass gives more higher end HP, more metallic rasp, more weight reduction
both bypassed considered too loud for sane street use by most

i won't comment on cat removal

also, darin fister working on his take on 964 exhaust mods -- shd see what he has up his sleeve

newsboy

I have tried both both primary and secondary bypasses. Did not like the sound. Went back to stock, but am con considering a 200 cell cat.

SRM11

It really depends what you like. Golfnut summed it up pretty good. I've tried basically every combo so here's my take

If you like loud cars, the primary bypass won't be loud enough. It's basically a slightly louder version from the stock sound.

Secondary muffler is quite a bit louder, and changed the sound to be a lot deeper, almost v8 type gurgle sound. Note there's the 'g pipe' and the 'long g pipe'. I haven't tried the regular g, but the consensus seems to be the long g has a better sound.

Cat bypass added to either will make it louder still.

I preferred the cat bypass + secondary muffler the most, but you definitely notice the gas + smell. It would also puff a little blue once in a while - only in hot temps/traffic it seems. But annoying enough that I put the cat back on and I get zero blue.

Current setup is primary and secondary bypass, with cat in place. It's very loud (although not that much louder than cat/secondary), raspy, and mean sounding. I love it. Your neighbors won't. I lay off the gas and putter into my neighborhood and it's fine. If you use it for daily transportation or longer drives it may be too loud & annoying, but I love hitting the backroads and listening to it nice and loud.

If you search around, there's a video someone made with all the sound differences. I don't remember where I saw it, but it helps to hear all of them.

andy73

I’ve run a few of these setups also. Firstly in terms of performance, I’d honestly say you could throw a blanket over all of these solutions and the performance changes aren’t all that discernable (unless you’re going to dyno the car and get deeper down the rabbit hole).

When I first got my car it had the stock cat, stock primary and deleted secondary (replaced with a G Pipe). As has been mentioned, this gives the car a deeper rumble that does sound good and aggressive, albeit without the as much of the air cooled rasp.

I then switched to a Cup Pipe with stock cat and stock secondary. Nice, raspy note but pretty quiet. Swapped the stock secondary for an FVD Brombacher secondary. This did add a little more volume but didn’t deliver on their advertised burbles and pops. On their advice I changed the cat to a sport cat (200 cell Fabspeed). This gave it good volume and retained the aircooled rasp. It’s probably my favourite tone that I’ve heard in a 964 but just lacking volume. You won’t have people commenting on how the car sounds but I liked it.

Most recent change has been Fister’s new 964 exhuast. Darin was super fast and easy to deal with. When I first fitted it, the combination of the Fister and Sport Cat was just too much. So loud! So I’ve swapped back to the stock cat. Driving with friends on the weekend they all loved it. I have to say that inside the car, it’s taking a bit of getting used to. It sounds terrific at WOT but definitely changes the character of the sound. Almost like a louder, more aggressive G pipe – I think it may just be a matter of getting used to it. It’s much deeper and ‘woofier’ in tone. The pops and burbles are absolutely sensational and the car now has a sound that has real wow factor – sounds like a worked performance car. In terms of performance it feels really rev happy and responsive - even with the stock cat reinstalled - so I'm very happy with that. Since reinstalling the stock cat it has got some resonance when cruising which I’m hoping to solve (not sure how) as I don’t want to live with that long term.

Kidasters

Everyone - thank you so much. This has been educational.

I'd love more pictures though.

Andy - your post has me considering the following: 200 Cell Cat, Cup Pipe, FVD secondary. Wow, FVD is proud of their secondary......

andy73

Yeah it's a nice exhaust, no doubt. To your point, I would say that the copy on their website overstates the sound of the exhaust (at least in my experience) "...a glorious flat six race car with low deep tones that reminds us of the 964 Cup" is not how i would describe it personally. I don't know whether going to a 100 cell cat would add more to it. Didn't get any of the crackles and burbles. Here's how it sounded before changing the cats

I'll say that the quality of the FVD muffler is lovely. It's a beautiful-looking piece of kit that's a bit wasted hiding under the car.

andy73

Here's a quick drive by with the Fister and 200 cell cat.

gregmitch

Wow that is loud. Is that just the Fister secondary or the full package with primary bypass?

andy73

That's Sport cat (200 cell), primary muffler delete (cup pipe) and the Fister. It's made quite a difference switching back to the stock cat (don't have any footage of that unfortunately). It's reduced the volume quite a lot. But still sounds really aggressive. Also I don't have any footage of the FVD with sport cat...

Parabolic

Ooo, do you know if Fister is about to release the 964 exhaust? I've been excited about it since hearing the videos of the sneak peak from Rennsport.