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I've searched the forums and can't find the answer so I'm resurrecting this thread to see if anyone knows. I have a single outlet B & B exhaust but want to change it to dual outlet. Do I need to replace the whole muffler for dual outlets or can I take the muffler to a shop and have them convert it to dual outlet? Would there be a problem in doing that? Lose power? Not as efficient? Thanks for any help.
Rey
Rey, you've probably seen several threads on this. I just purchased a dual outlet fabspeed system. Great product. Really like the sound, the fit and finish. Some in the past had drone issues, but I think their engineers resolved this as I have none. I say hands down pick one up if you want a dual exhaust. If you want a complete header system with dual exhaust maybe the fvd might be better? not sure but I don't think modifying your existing setup by welding in a port would be a good idea.
Edit to add. I've seen an aftermarket exhaust that was "modified" to add another port and it was bad enough the PO removed it and went back to single exhaust.
Rey, you've probably seen several threads on this. I just purchased a dual outlet fabspeed system. Great product. Really like the sound, the fit and finish. Some in the past had drone issues, but I think their engineers resolved this as I have none. I say hands down pick one up if you want a dual exhaust. If you want a complete header system with dual exhaust maybe the fvd might be better? not sure but I don't think modifying your existing setup by welding in a port would be a good idea.
Edit to add. I've seen an aftermarket exhaust that was "modified" to add another port and it was bad enough the PO removed it and went back to single exhaust.
He has a B&B exhaust (mentioned in post # 62). I have the same set up and have a single exhaust pipe, but I was the one that installed it in my car and if I remember correctly it should be pretty easy to swap the muffler for the one with dual outlets. Oh and +1 on not trying to weld the extra port to original muffler.
resurrecting an old thread, rather than starting a new one....
My exhaust experiment started with a primary bypass from vertex. With the stock cat and stock secondary muffler, the note sounded like a "tradional" air cooled 911... quite nice, definately not loud at all. Performance felt slgihtly improved.
Second, I changed the cat converter to the fabspeed one... the note was only a fraction louder. Performance was same. But now I had lots of gas smells.... not sure if that is because I ditched the cat converter, or because I had a leak at a joint....
Third, I put the stock primary muffler on, then fitted the Dansk secondary muffler bypass.
Engine note is hard to describe, but it is different... sounds a bit more of a "hooligans" car...
However, performance feels much brisker, especially down low...Not sure if I am imagining it to be honest......
I will try to take some video soon.... I do not like this exhaust sound as much as just the primary bypass...
I did the same experiments. The exhaust that gives the best performance, if you chance nothing but the exhaust, is the stock one. Changing each of the other pieces cat, primary, or secondary, causes issues that need to then be addressed....
I liked the g pipe best for sound. And will likely go back to it in the spring
.....The exhaust that gives the best performance, if you change nothing but the exhaust, is the stock one......
Correct - the primary bypass, which was the Euro Carrera Cup set-up gives slightly better top-end, which is fine for race cars that are running at the top of the rev range most of the time. The G-pipe improves low-end torque at the expense of the top-end. The stock system is really the best all-around system.
"Here are the flow rates for 964 exhaust broken down by component,
Section Flow Rate (CFM)
Catalytic Converter 442
Primary Muffler 396
Secondary Muffler 462"
"FWIW the most weight is lost bypassing the secondary, but the weight is not at the end of the car as in the saving the primary effects and mimimal in difference.
Primary Muffler Weight 23.5# minus Primary Bypass 7.75 pounds= 15.75 pounds saved
Secondary Muffler Weight 23.25# Minus Secondary Bypass 3.75 pounds= 19.5 pounds saved
So bypassing the secondary saves 3.75 pounds more.
This is weighing factory Cup bypass parts.
Given all of above I went with the better flow of the secondary and bypassed the primary."
No chip "needed" for sure...and like I said before, the best of the stuff i tried overall was the stock exhaust.
That said, I bought a Steve wong chip, standard one for 91 octane, and with the pipe deletes, it helped a lot in over all performance from a driveability perspective. Just my two cents. I'm a Steve wong chip fan.
The 964 exhaust has two mufflers - a primary muffler (#8 in the picture below) and a secondary muffler (#9 in the picture). It will also have either a catalytic converter or a 'bypass' pipe, depending on country of sale (#6 in the pic).
A 'cup pipe' or 'primary bypass' pipe will replace #8.
A 'G pipe', 'U pipe', etc. will replace #9.
You can also install an aftermarket catalytic converter bypass.
This is a 'cup pipe' or primary bypass:
This is a 'G pipe' or secondary bypass:
And this is a 'European' style catalytic bypass pipe:
I would have no idea what I'm reading about if it wasn't for this photo lol.
I would have no idea what I'm reading about if it wasn't for this photo lol.
Here's an updated version - some of the picture links are dead, plus IB changed their software so linked photos in old posts don't always work.
Originally Posted by Ken D
The 964 exhaust has two mufflers - a primary muffler (#8 in the picture below) and a secondary muffler (#9 in the picture). It will also have either a catalytic converter or a 'bypass' pipe, depending on country of sale (#6 in the pic).
A 'cup pipe' or 'primary bypass' pipe will replace #8.
A 'G pipe', 'U pipe', etc. will replace #9.
You can also install an aftermarket catalytic converter bypass.
This is a 'cup pipe' or primary bypass:
This is a 'G pipe' or secondary bypass - first pic is short tube, second pic is long tube with mounting brackets:
And this is a 'European' style catalytic bypass pipe:
When I bought my c4 a few months ago I found that it had been equipped with a B&B exhaust. I must say, any louder and it would be annoying (to other drivers) and any softer it would be annoying (to me). I have never found it to ever drone and it sounds fantastic. I recommend it highly
02-20-2014, 07:06 PM
