CLS55_Ian

I am looking to upgrade my exhaust and want the power gains of long tube headers, but I want my exhaust to be as quiet as possible. Im thinking of getting the MBH LTH with X pipe and keeping the factory resonator and mufflers. Is there a better strategy for getting the power gains of LTH while minimizing dB's?

lost27

I have the American Racing long tubes, 200 cell cats, factory resonator, and factory mufflers. It isn't loud at all unless you get on it and even then it isn't super loud/annoying. With the windows up I can barely notice them. That said, they ARE louder than the factory exhaust.

tlambert

Mine is set up the same way. AR LTHs, 200 cats, x pipe, factory resonator, stock mufflers.

Sounds just like what lost27 described.

CLS55_Ian

Thanks for the input guys. Would not having the cats make it significantly louder? I gotta assume the answer is yes. Would keeping the factor cats be a bad idea?

I want to go with MBH because they are the only ones who guarantee their numbers, but buying the MBH headers+Mids+Cats is like $4k. I can save a few bucks if I go with the headers+mids+xpipe, or if I can use my factory cats.

MBH motorsports

You can not use your factory cats. The wont fit. They are huge.

Fountain35

I sent you guys an e-mail with a couple of questions over a week ago and I never received a response.

99lightning

st
stock tuned vs mbh with stock rear cats. could be about 10hp higher with mid pipe.

C_Note

That’s stock tuned, no pulley numbers? Was it a pain retain rear cats or would it be easier, have more clearance, with aftermarket cats?

UncleBenz55

Stock 2ndary cats with long tube headers is no issue. I have mid tube headers and stock 2ndary cats too and its not too loud for daily driving. You just need someone who can weld, to make it fit.

MBH motorsports

Please email me again

C_Note

any gas smell? I’m lookin to do LT asap. Ol boy buyin the cats on here had me thinkin, sell mine and go aftermarket

UncleBenz55

My friend once drove behind me on the autobahn and he said there was a slight smell when I floored it. But on normal driving there was no smell. In the car you don't smell anything though

tw2

I have tri-Y long tubes with aftermarket cats. Stock resonator and mufflers. In the car it sounds the same. Open the window and it is definitely a bit louder than stock. Cold start.... Still drowned out by the oil pump! Headers alone is the best compromise for power and quiet with the exhaust.

CLS55_Ian

Why did you decide to go with aftermarket cats? Are the power gains significant over factory?

tw2

Keep noise increase to a minimum, I don't like the smell and legal requirements in my country based on the year the car was imported. The headers definitely added a bunch of power. I think I dyno'd 500whp with a 83mm pulley, tune and some supporting mods as well.

C_Note

i don’t want the smell in my clothes. Gasoline and Polo Black might not mix well 🤣😂

C_Note

which cats did you go with and how many?

remix405

Lth with no cats to factory resonator and factory mufflers is still very quiet.

lost27

At this day and age and with the newer high flow cats there really isn't that much of an advantage running catless anymore. These cars with 200 cell cats, long tubes, a conservative pulley, cooling, and injectors will make reliable 500+ HP all day long which is more than plenty IMO. Here is a post comparing what a difference longtubes make on a lightly modded car: https://mbworld.org/forums/c219/7351...ml#post7784990

ArmoE55

The resonator on the W211 E55 does little to NOTHING for exhaust volume. It you remove them, you can see the 'straight through' design. The main advantage is weight savings as anything factory on these cars are HEAVY. The mufflers are some of the most baffled ever produced by a manufacturer. Until something is done to the mufflers themselves, these cars stay relatively quiet (in comparison to other cars with the same exhaust upgrades) even with long tubes and catless.

CLS55_Ian

So what are the resonators there for? Im sure Mercedes didnt put them there for no reason.

JohnLane

They mellow the bent eight bark.

nd-photo.nl

Resonators are usually in place to remove drone. My center resonator is removed and I have no drone whatsoever

-stock headers
-stock downpipes
-stock cats
-stock mufflers

ArmoE55

To make our lives more complicated, I don’t know their reason. You guys gotta have cat-like hearing to notice even a drone difference with the resonator; I daily my E55s and on the prior two, I noticed absolutely no difference in volume or drone change. Just personal experience- resonator does nothing for volume on the W211 E55.

This is my third E55 and the first two I took the resonator off and replaced with straights. Zero difference other than some weight savings.

CLS55_Ian

Just providing an update to anybody who cares. Got some long tubes off alibaba for dirt cheap ($400) which came with a x-pipe mid-section. The xpipe didnt fit right so I ended up having a custom mid pipe fabricated. Now I have long tubes with xpipe with resonator with mufflers, no cats, 83mm pulley, PLM XL HE, and Vtech tune. Its definitely not quiet like I wanted it but it sounds pretty nice. The performance gain with the cheap chinese headers is pretty impressive. Now need to find a place to dyno my car, I want to know the numbers.