Exhaust Mods

[abl567]

Thanks to the Godfather I finally got hold of a factory 6.3 rear muffler to replace the, cough, AUDI unit in place and restore the exhaust to as it should be.
The 6.3 needs a cross over pipe between the pipes soon after they exit the manifolds to make power, mine had no cross over pipe, relying on a 2 into 1 muffler just before the rear axle, a single 2.75 inch pipe over the axle into the rear 1 into 2 muffler. Was it restrictive, you bet.
It didn't make sense to simply fit the factory muffler and see what happens so I had a cross over pipe fitted just after the tranny cross member, twin straight through cans just before the axle, twin 2.75 inch pipes over the axle into the factory muffler, which is also a straight through design. Does it sound good and go hard, you bet.

Sorry no pics...or sound

 

[GreaseMonkey]

Funny thing that.
I have often wondered why hooning f*ckwits think their V8s will go better with straight through pipes, probably cheaper, and hopefully louder which equals faster doesn't it?
Well no Mr P Plate Hat-On-Backwards Commodore, it doesn't.
The balance pipe is there to compensate for the firing order of the V8 and provide correct back pressure and frequencies to help evacuate each cylinder on the exhaust stroke, increasing efficiency AND power.
Thanks for posting that, ALL Merc V8s should have the correct set-up, twin down-pipes linked by the balance pipe, and then dual pipes into the mufflers.
Hope it goes good now.
Chris M.

 

[B13]

Except 6.9s

 

[TJ 450]

Yes, there is also no balance pipe on my 6.9 and the front pipe is original AFAIK. I wonder why this is so?

Tim

 

[B13]

None of our, or anyone elses 6.9s have them, not needed.

MB would have done dyno testing with and without a balance pipe I'm sure, but didn't end up including it in the design.

Ian.

 

[s class]

This is interesting - I'm having a new system made up for trusty rusty, and I was always under the impression there was no balance pipe or X box in 6.9's. Until I saw this picture in the EPC :

???????

 

[CraigS]

Can't say I have ever checked any of mine, so can't answer that one. Must ring RonB and ask him if the one he is driving has one.

This is something I also need to do for my 6.3. I have a pinging problem that I have never been able to resolve, and this might help part of it.

 

[s class]

RonB has made his comments over at M-100.cc

 

[GreaseMonkey]

Interesting, as B13 said, MB would have looked at this. I wonder if there is something in the length of the front pipes, or the baffles in the front muffler that compensates for this?
Exhaust design is one of the balck arts that we never really need to question.
Chris M.

 

[John S]

It seems that the front muffler is used as the balance point. The length of the pipes to the muffler would have been chosen to meet the power / torque requirements.