luv2race

I saw the video. Ha
I haven’t found mine to be too loud or annoying yet. I love the sound personally.

Fabspeed Motorsport

Hey Kurtamma, all of our systems are direct bolt-on installs. Unfortunately, we do not have any media currently available.

Shoot me a PM for forum pricing!

911Jetta

Thanks everyone for keeping the conversation going. Once we get the discussion terminology straight, let's see if there is a difference and why.

In the posts above, looks like we've uncovered most of the names we associate with the J pipe. (swans neck, long g-pige)

We are talking only about deleting the secondary exhaust (regardless of what's happening upstream - like: cat bypass, primary bypass, etc.)

To that end, I'd love to know more about the sound characteristic of changing either the length, angles and maybe even the tubing diameter.

The j-pipe definitely sounds different that g-pipe. 100%.

I like the g-pipe, but it's definitely louder, deeper, and has a woof, woof Subi/Harley sound. To some, the sound is far from the traditional flat six sound. I don't dislike it, but for the reasons mentioned I'm struck by how much I like mine in comparison, and the main difference that I currently notice is just the length of the pipe.

I love my J-pipe bypass and if for whatever reason I couldn't use it any longer, I would switch to a primary bypass over a g-pipe bypass.

I always appreciate when people ask questions that promote a better conversation. We're all friends here.

Interesting that you call your primary a J-pipe. The majority on this forum would/should associate a primary bypass as a "Cup bypass". It was the factory exhaust set up for the Carerra Cup series, hence the common association.It's the Cup bypass (or at the very least a primary bypass, given where it is).


Exactly. It's a point others have mentioned many times on this forum. The g-pipe bypass is the loudest option. Many who have had one love the sound but in come cases it's too loud for their lifestyle.

This point is made more interesting by the fact that I also have a cat bypass, and it's still not overly loud with a j-pipe.

The j-pipe really shines when matched to a cat bypass. 10% louder (ie: slightly) but much more mechanical sounding. (!!!!!)

I've tried all the bypass combos also, and agree.
For me, no need to go with headers or anything else custom. Especially since these changes are cheap and easy to make (or reverse).


I'm taking just about choosing one bypass. That's what the majority of us would do, it's a simple and makes a big impact on the sound of the car. Either the primary or the secondary.

Thanks for asking that question. Yes, the j-pipe sounds that good. It's louder and more mechanical than choosing a primary bypass instead (which I had for years in another car and loved also).

When I bought this car I knew it had a secondary bypass and I thought I would be switching that for a primary bypass instead. I was very pleasantly surprised when the driver started it up and it rolled off the enclosed trailer. Per the sellers spec sheet, I thought it had a g-pipe... but it had a j-pipe and I knew I wouldn't be changing anything.

That was the moment it hit me how different they sound and hopefully this thread will give me some answers. (thanks in advance)

Regarding flow (and the weights of each bypass option), it's all close enough. It's accepted that a bypass might only bring a couple horsepower at best, so leaving 2 horsepower on the table at the benefit to the sound that YOU enjoy is no big deal. Losing 20 pounds behind the bumper verse behind the passenger rear wheel, also no biggie in my book.

Bigsix964

Right on, thanks for your answer. I agree - losing 1-2 HP is insignificant if it gets you the sound that you like. I was envisioning a bigger delta there.

Interesting you say the Secondary bypass is more mechanical; would love to hear a clip of your car from inside with the longer pipe.

911Jetta

Yeah, regarding a performance difference we’re totally splitting hairs here. But the sound is different.

I don’t have any way of accurately recording sound to persuade anyone one way or the other. Free rides to anyone that visits!

As much as I like it on cold start, and accelerating through the gears, I really love the in steady throttle in cabin sound from 3,500 -5,000. Super tight mechanical roar.

I think the drilled air box, stiffer motor mounts (and Function First trans 50A insert) all contribute to the NVH sound/experience.

911Jetta

BigSix, what are you running, and what do you like/dislike about it?

Bigsix964

My setup is very vanilla - cup pipe only.

Like:
1) The note, especially in the middle of the tach. The classic 911 song that never gets old.
2) Overall volume level seems to be a good compromise.

Dislike: Not a whole lot, but I haven’t heard a ton of setups, so whether or not it’s my favorite is TBD.

luv2race’s vid up there sounds much louder and angrier than my car, presumably from the cat bypass. The main reason I’m hesitant to open it up more is the soft top - the dBs at the wheel go up dramatically with it down and the note gets much deeper. If it’s a little quiet closed, it’s perfect when open. I think for the coupe folks, going the extra step probably balances that scale.

The great thing about these is that it takes a half hour to change stuff around.

Might have to take you up on that visit! Western NC is unreal. Mrs and I stayed in a cabin off the grid in the Pisgah forest a few years back and it was so hard to pack up and leave...

911Jetta

I know that set up well. You mentioned "classic 911 song" and that's the reason for the deeper dive with these options. The sound and volume is different depending on the bypass. No judgement.


It's easy to get greedy and end up too loud or an unpleasant tone. I get the cab situ very well. My dad has had a 964 cab for over 20 years and last year he finally agree to go for some of the home run mods. New motor mounts, Steve Wong 93 chip, Golden rod shifter, solid tie rods, steering rack brace, plus a couple more goodies. It really transformed the car! I was very careful about the exhaust selection... based on my past experience decided the primary bypass was the way to go. Classic sound, only a bit louder and he loves the howl when he gets on it. I understand what you mean about the car sound experience, and the primary bypass perfectly compliments it. Looking back, I'd definitely add a cat bypass but since he was used to "stock" for so long, he's very happy with the change.

I sense another Rennvisit in future. Love the Pisgah area and maybe we can arrange to meet up with a couple RLs who live in the area.

911Jetta

John at Fabspeed, I'm sure you are very busy, but would love an update when you have a minute. Many thanks in advance.

Fabspeed Motorsport

Hey Jetta,

Wish I could be of more help!
As I pointed out in my prior response, we do not offer any variations to our secondary muffler bypass. Therefore I cannot give any insight into the performance differences between the two styles.

If anyone has the FVD system and is in our area, feel free to stop by our next Open House and we can throw it on the dyno. Always happy to investigate on behalf of the Rennlist community.