W211 E63 Exhaust sound improvments

[c_200k]

Yup

When you get under the car you'll see the Secondary cats near the front then the resonator in the middle part towards the end before the back boxes.

So you car taking out the Secondary cats ONLY first!

Those oval things are Secondary cats after the Stock H Pipe

 

[daveenty]

Starting from the front you have: -

Primary cat: Leave this in place
Secondary cat: Up to you but removal would be fine and good
Resonator: This is where the pipes join, either remove and replace with an X pipe or leave alone (First mod to do really)
Back boxes: Leave in place unless you really hate you neighbours.

HTH

ETA: @C 200K. That's the first time I've actually seen the stock system on these from underneath. If that was mine/me doing it, I'd get rid of that lot from just before the H pipe and just run straight pipes to the resonator area. Then swap out the resonator for an X pipe.
The only ones I've looked at with interest have had headers (Sorry, Americanism) and not that stuff which must really restrict the flow...

 

[BillyW124]

Starting from the front you have: -

Primary cat: Leave this in place
Secondary cat: Up to you but removal would be fine and good
Resonator: This is where the pipes join, either remove and replace with an X pipe or leave alone (First mod to do really)
Back boxes: Leave in place unless you really hate you neighbours.

HTH

i thought the primary cat is the resonator i.e. in my terminology the main cat?

the X pipe is used instead of the secondary cats to fill the gap of the H pipe?

 

[daveenty]

See my edit.

The Primary cat is exactly what it says, the catalytic converter, used to save seals and puppies.

Resonator is as posted by the gentleman above.

Supper here, panic on...

 

[BillyW124]

....ah yeh dont worry about puppies and seals. I run a high octane gas guzzler!!

thanks chaps!

 

[AMGeed]

the X pipe is used instead of the secondary cats to fill the gap of the H pipe?

Correct.
Here is my 55k with both secondary cats and resonator removed and x-pipe installed.

If you look from underneath,up toward the engine, you'll see the primary cats with an O2 sensor plugged into each downpipe.

 

[BillyW124]

thanks for that boys much appreciated.

order of the day then, rid of the secondary cats and install an X pipe but keep the primary Cat.

...then see if it scares the girls next door cat. might delete that too!

 

[daveenty]

I used to have those cat things on mine, bit restrictive though...

See HERE for amusement...

 

[W126]

If, hypothetically, one was to require slightly more bark low down the rev range, what would be the best option? (CLS55)

 

[Alps]

time to visit EMP

 

[BillyW124]

Update to my existing thread. pics and link to the sound clip..... X pipe sounds epic!!

http://www.mbclub.co.uk/forums/gene...e-dont-curse-i-bought-63-a-3.html#post2064396