Hi guys,

Decided that I would try to improve the car sound, making it more "bassy", I'm thinking of starting with the G pipe by deleting the final muffler. I have a few questions that I' be been checking for answers in a few posts, but the information is so much that I loose myself in the middle, so i decided to asks our help by posting directly my main questions:

- will this make the sound of the car more "bassy"?

- will the car suffer loss of power at any rpm?

- do i have to also delete any electronics in the car? Is it only plug and play?

- is this called a primary or secondary bypass?or any?

- in europe we have emissions inspections every year, will this change make the car have more CO2 emissions? This will lead for me to change the g pipe back to the muffler every year, not a problem though.

- is this the first best change or should i go first with the cup pipe? I Want to test by steps so that the sound isn't too much for my ears.


Sorry for all the questions, i really apreciate your help.

Thanks

 

Here are 3 answers:

- Yes, plug and play - no electronics changes needed (fairly easy install)

- It is called a secondary bypass (or g-pipe)

- I personally like the primary bypass (cup pipe), but there are opinions for both options. (just only do one).

 

G-Pipe all the way man. Sounds even better if you do the cat delete as well but then you'll breach the emissions test. But then again it takes approx 20 mins to swap over the cat pipe.

 

Must depend on individual cars as mine has comfortably passed the emissions test for the last 4 years with no Cat and either a G Pipe or for the last 2 with a Cup pipe

 

It'll depend on the actual country. I know in the UK and France mine passed OK without the CAT, but I need to have it fitted in Italy for it to pass the emissions test. Also in Italy we have noise regulations which prevent you from making the car any louder..

Either way, it doesn't take long to refit any part of the exhaust to ensure it'll pass the tests!

For me, the best is the CAT and Cup pipe route rather than the G-Pipe.

 

Here's my Cat+Primary+G-pipe.


Primary+G-pipe versus Cup pipe+Secondary is a different sound.

G-pipe sounds pretty low, bassy, and hot rod. Cup pipe sounds more compact and focused, and more Porsche.

 

I have installed two configs on my RSA
1) cat delete, cup pipe, secondary muffler' k&N filter w/open box
2) cat delete, primary muffler, g-pipe, K&N w/open box

Notes and observations
a) plug and play
b) config #2 has better deeper sound
c) better throttle response
d) need to keep one muffler on for some back pressure or there is a negative hp effect
e) Fabspeed dyno claims +17hp with config #1.

Rob

 

Wow guys, thanks for so much precious information!!!

I'll start with the g pipe and go from there...the cat delete seems to me the most expensive change, so I'll start with the two least expensive and try to reach the perfect tone I'm seeking!

Vandit, that's a cool 964!! (Mine is white also)) at first I didn't appreciate it too much, but now it's one of my favourite colors for this model

I try to check videos with g pipe only but I can't find any....if any one knows one please indicate me.

Here I go ordering the g pipe plus a strut bar....my first mods in the 964!!

Thanks

 

Great thread guys! Vandit thanks for the nice video. Love the nice tire sound going around the corner!!
I too am going to install a G-pipe this spring so this is very helpful. My car came with the primary bypass which I will be reversing. Any DIY on removal/reinstall of primary?
Also, I was curious if anyone alters the cat rather than a bypass? I had a 944TS that the PO had rammed a rod into the cat to create more flow.
TIA

 

Careful w/ your respiratory system if you attempt to "gut" your catalytic.

 

Vandit, if you are referring to smog testing MN does not test for that any longer. Not sure I would do it but was just curious if this was done to get a similar results as a bypass.

 

I've just ordered the G pipe! Can't wait to try it!

 

Any advise on how to preserve the muffler so it doesn't deteriorate over time? I may have to reinstall it so that the car goes through smog inspections, so I would really like to keep the muffler prepared.

Is there any thing I can do so it won't deteriorate?

Thanks

 

Its stainless, so you wont have any problem

I left mine outside for 18 months (in the UK) with no adverse effects

 

A muffler or lack thereof shouldn't affect exhaust emissions. Unless you live somewhere that has a visual inspection that requires all the original equipment being installed you should be ok.