SL 55 TOO LOUD!

[DanSL55]

I just bought an SL55 after a year or so of enjoying a very nice SL500.

I absolutely adore driving it, can't believe the power, still getting used to it, still tinkering with it, still cleaning it, still filling it with petrol.

The only thing I DON'T like about it, and I can't believe I'm saying this, is that it's TOO LOUD! It's had the back boxes removed, so it now has the first set of cats, then straight pipes to the tips. It sounds fantastic starting up and burbling along the street at 30 but on the motorway it's like having a meschermitt engine on the luggage shelf. Splitting headache after an hour.

So, luckily the former owner still had the back boxes, and I'm planning on getting them refitted.

Now I like a nice burbly exhaust, but I also like to be able to drive my once £100K car along the motorway for an hour without getting a headache. So my question is, am I going to be disappointed with the stock exhaust sound? Is it sacrilege to do anything that doesn't make it noisier? Or am I doing the right thing in returning the car to it's former balanced elegance rather than the boy-racer version?

 

[Deleted member 113659]

Too loud? Are feeling you ok pal???

 

[Wearsthefoxhat]

As you have the parts, perhaps put it back to standard and see how that is.
From there you fit a cross over,(x pipe), remove the secondary cats. Bit by bit until you like the sound.
Personally I only like a lot of noise when I really put my foot down. Nice burble when just driving around.

 

[DanSL55]

As you have the parts, perhaps put it back to standard and see how that is.
From there you fit a cross over,(x pipe), remove the secondary cats. Bit by bit until you like the sound.
Personally I only like a lot of noise when I really put my foot down. Nice burble when just driving around.

That's the plan really... I'm hoping to get them to put the boxes back using clamps rather than welding, so if it's too tame I can get it reversed easily.

Or maybe I'll get some ear plugs for the motorway.

 

[DanSL55]

Too loud? Are feeling you ok pal???

I'm rather surprised myself - doesn't sound like me at all!

 

[Dickster]

With me it’s an age thing, I used to love them loud. Personally, I think they got the SL55 spot on as standard, when you open it up it makes a lovely noise.

 

[Wheelnut58]

I’d put it back to standard, I like the noise my Slk 55 makes when your on it, but the rest off the time prefer a refined growl, there was a guy in Harrogate the other day, riding round in low gears sounding like thunder in traffic

 

[DanSL55]

Thanks all for your advice on this. I think I will go ahead then and get it put back to standard tomorrow, but ideally with flexibility to change my mind!

Except I'm just reading about a guy who set his up so he can switch the noise on and off... hmmmm

Exhaust Modification with twin electric cut out and quad tips done. | Performance Lounge

So I have just carried out a nice little exhaust modification from the stock SL twin oval pipes. I've added a twin electric remote exhaust cut out with deleted rear ovals in place of quad pipes. I wanted to keep the car quiet when on my 6 hour weekly commute, but have some fun when I want! ( I...

forums.mbclub.co.uk

 

[Senator]

Is it more noisy at a particular rev range? If so it It could be drone that is occurring at the system's natural resonant frequency. You don't necessarily need more silencing, just a resonator that targets that frequency (like a J-pipe for example). You can use a spectrum analyser app on your phone to see if there is a spike at a particular frequency range.

 

[Wolfie1]

What about getting some active back boxes fitted, press a button and they are loud then press again and its quiet

 

[Wheelnut58]

A friend and forum member had this done to his car, he could switch as and when he wanted

 

[E55BOF]

It wouldn't comply with the Construction and Use regs, or pass an MoT, with that open, but I've never objected to loud cars, only the bozos who take every opportunity to p!ss of 90% of the population by making lots of noise at every opportunity. My SLK is bloody loud at full chat (resonator delete, came to me like that), but it doesn't drone on the motorway; it's great when I'm in the mood, but not too bad driving around town.

OP, it sounds as though your secondary cats and/or resonators (if the car ever had either) are gone as well. Put your back boxes back on and see what you think; you can always modify it further if it still drones or is too quiet, but I suspect it won't be.

 

[John]

I'd put it back to standard and see what you think.

I had an E55K, which are quieter stock with more baffle in the stock backboxes, and I put in long tube Kleemann headers, X pipe and lost all the CATs.

Sounded great but I deliberately didn't touch the backboxes as I didn't want drone or too loud which I'd heard on those had the work done to backboxes.

Had I kept the car, I would have fitted CLS backboxes and 200 cell CATs as the CLS backboxes are louder and the car stank with no CATs...

 

[Gbrowncls55]

Even in standard form it will burble nicely on cold start and roar /rasp on full throttle. The rest of the time (90%) it will be far far nicer to drive.At least thats my experience with the CLS55. I love hearing loud cars ....but preferably other peoples

 

[DanSL55]

Hi - OP Here.

Thanks for the great advice. I was really in two minds about whether to do it, but decided to go ahead and put it back to standard.

However, it turned out the SL55 back boxes that I bought with the car... were SLK55 back boxes! The guy I bought the car off, lovely old guy, with a collection of 20 incredible classic cars, also had an SLK55. And he muddled them up. So he's now looking for another pair of back boxes with AMG written on the pipes in amongst his pile of treasure - if he finds them I'll find a reason to drive from London to Manchester to swap them over.

Otherwise, does anyone happen to have a pair I could buy? Or (somewhat unlikely) want to swap SL55 / SLK55 boxes!!!

The exhaust is apparently otherwise standard.

Wheelnut58 - I love the idea of switching the noise on and off!

 

[DanSL55]

I also have a track day at Thruxton on Friday - my first such thing for the better part of 30 years. I will be very pee'd off if I'm told it's too loud.

 

[Gbrowncls55]

Possibly cls55 or e55 boxes could be made to fit or may be a direct sub

 

[Alps]

defo replace the boxes.

My previous E55 had headers and c36 back boxes, middle silencer and secondary cats still in situ and sounded great, current one has primary cats x pipe and c63 back boxes, still not bad but can drone at 90... not that id drive at that of course... but I think it would still be too loud for the track.

 

[AMGeed]

As Alps above, refit the rear boxes.That is the problem.
It should sound perfect with just primaries, sec cats and resonator removed, and SL rear mufflers in place.

 

[Merc55k]

Possibly cls55 or e55 boxes could be made to fit or may be a direct sub

I might have a pair of CLS55 Supersprint backboxes available soon, they are much the same sound as standard but a fraction of the weight. From memory they were around £2200 new for the pair. If any one was interested drop me a DM.