126 gasser exhaust size (replacing)....

[LandYaghtLover]

560 SEL. After my exhaust dropped again I figured it will soon be time to replace the whole thing. Shop will do from manifold on back. With the cat gone, I should free up some HP.

Question is what size pipe would be a good fit. Stock looks 2 or 2.25". I know that some think back pressure is a myth and some say its needed. I am NOT looking for loud exhaust. In fact I want it to be as quiet as possible, even more so than stock if possible. Shop can even do double-walled. But I dont think I will go that far.

So if you wanted good flowing but very quiet exhaust, what setup would you build? And with the cat gone, will anything involving engine management have to be tweaked?

[rsmartin]

do they not inspect cars or at least do emissions inspection where you live?? no way you can get a way with deleting the cat where i live.

[pawoSD]

Originally Posted by rsmartin

do they not inspect cars or at least do emissions inspection where you live?? no way you can get a way with deleting the cat where i live.

Michigan/Wisconsin don't do inspections of any kind I believe.

However, on a gasser it is relatively irresponsible to run no cat at all. There should at least be SOMEthing on there.

[Hit Man X]

Stock is dual 2" from memory... after the cat. That stuff is fairly free flow (muffler/resonator), the motor does not rev very high and does not make much power anyway. 240hp (when new) from 5.6L is nothing to rave about. I would be surprised if they belt out over 200hp now. So dual 2" will not be restrictive in my eyes at all.

Most gains are going to be seen getting away from the comical Y pipe manifold setup and dumping the cats. Cats from the 80s do not flow well. Running a cat is up to you, I do not care... many more things pollute far more than your catless vehicle.

Even a set of the ECE dual logs are going to flow significantly better than the US bits. In fact, this is the same thing I am doing... I just swiped the parts off a 500SEL. Realistically I bet 15hp is to be had just with that. You can always port match the manifolds to the gaskets for a bit more flow too. Every little bit helps.

[LandYaghtLover]

No inspections here. And yes, the few number of users who remove cats pale in comparison to what an airplane puts out in its lifespan. And what about people who drive cars pre-cat?

Anyway, I read more and see that the four part manifolds are the most critical part of the setup. So I will be hunting for those first before I have the shop see what they can then do. From what I can see, its the earlier years that have the four part manifolds? I was looking on the German eBay and the later manifolds looked no different from the US version.

[lkchris]

Originally Posted by LandYaghtLover

Stock looks 2 or 2.25".

No, "stock" looks metric.

[pawoSD]

The US spec 500/560's were incredibly de-tuned....the real fun comes from a euro-spec 560.

[LandYaghtLover]

I wish I had a Euro in the first place. I love power on demand, so I really want to get every ounce out of the 5.6 that I can. I think the first start is a dyno run just to see how she is now.

[JohnM.]

Yeah. The fact that a 300E is exactly as fast as a 560SL is pretty funny.