Don't like the 575 X-Pipe addition, removing it.

Can't speak for the 575 ... but on my 550, when I added a Stebro X-pipe to my existing tubi's it made a really big difference. When I added the tubi's first, I got a lot more low end volume but this decreased as the RPM's went up, to a point where they weren't any louder than stock mufflers. Adding the X-pipe unleashed the true V-12 sound though the whole RPM range and gave the exhaust sound more of a narly, higher pitched scream, which I really like. Can't drive through a tunnel anymore at anything less than full throddle and max RPM's ....... Unbelieveable !!!!

 

Scot,

would adding the stebro X pipe make the noise level too loud at cruising speeds?

Tarek

 

fwiw, I have just Tubi mufflers only on my 575 and like the sound a lot. Its plenty loud. At one point I was thinking x-pipe addition, so glad to hear about your experience. I took a while for me to realize that when I'm driving 575, I want it to sound like a Ferrari but not to the extreme (I have CS for that). 575 with Tubi is just right.

 

X-pipes do strange things to exhaust tuning because they cause a mixture of the exhaust pulses from both banks. This mixture is known as "cancellation" but not effective cancellation.

They also add resistance to exhaust gas flow.

So, while you think they are achieving, they are in fact not.

The bottom line is that proper exhaust system design will yield greater results.

 

It's my belief that the OEM center muffler on a 550 also mixes the exhaust side to side the same as an x-pipe, installing an aftermarket x-pipe is basically the same thing but with one less muffler in the system. To me, the x-pipe made the biggest difference and gave me exactly what I was looking for as far as exhaust note ...... yes, it's a bit louder but not at all a discomfort inside the car at all speeds.

 

I can only speak for my 550 .... but the interior sound level is fine. I really can't hear a big difference unless I roll down the windows and hit the gas. At freeway speeds my cars interior sound level is in no way intrusive or too loud. You're welcome to hear my car .....

 

"It's my belief that the OEM center muffler on a 550 also mixes the exhaust side to side the same as an x-pipe, installing an aftermarket x-pipe is basically the same thing but with one less muffler in the system."

I don't think this is the case. They may use a solitary muffler for space limitations, but usually there are separate tubes running through this silencer.

I do not know for certain on the 575. I am speculating.

Removing mufflers is not always the best way to chnage the exhaust note.

 

X pipes for V12s not as useful as on American V8s w/a 90 degree crankshaft.

Good article for American V8s: http://www.insideracingtechnology.com/drgas.html

For the V12s:
http://www.jagweb.com/aj6eng/faq.html
Why don't you have a cross-over pipe between banks on your performance exhaust systems for the V12?

It is true that a crossover can be of benefit to conventional V8 engines (with two plane crank) but only because they have an uneven firing sequence along each cylinder bank, which creates the rather delightful V8 exhaust note. A consequence of having two cylinders firing consecutively on each bank is that the flow rate is briefly doubled, then later in the cycle the long gap between firing impulses halves it, compared to the average flow rate. The temporary high flow rate means the V8 can benefit from using larger exhaust pipe sizes than other engines and a cross-over pipe can help to even out the impulses. It is not obvious but the Jaguar V8 has such a balance pipe within the main silencer box.

A V12, on the other hand, has equally spaced firing impulses along each bank creating an even sequence of pulses. There is no flow variation to require a balance pipe and the system does not have to contend with brief periods of peak flow so pipe sizes can be smaller. The only reason the V12 E Type had a balance pipe was simply to tune the exhaust note.

 

Exactly. The 550 does "siamese" the exhausts within the centre muffler as standard. I have tried straight pipes as well, with resonators and on my car it was louder than the crossover pipe with no resonators.

One config I tried was cats left in straight pipes with resonators and MilleMiglia mufflers. The car was so loud it was unbearable, this coming from a guy who runs no cats, no centre muffler and pre 202 Tubi's is saying a lot!

 

Does anybody know where is the best place to get straight pipes to replace the center exhaust on my 2002 575M?