W204Motorsports

All these cars have 2.25'' diameter exhaust. The x pipe alone will only get you more sound in the upper rpms. From the cabin and normal driving, you won't really notice it until you get on the throttle. For some people, it may be too quiet but i've heard a c300 with an x pipe and muffler delete and it was way too loud for my taste.

Here's my setup:

Cold start:


4000rpm Rev

Shimee

Sorry I measured wrong. The external diameter is about 2 ⅜" for the exhaust piping. I measured the inlet on one of the old mufflers where it was was welded so I unintentionally measured twice the wall thickness.

When you order parts you order by internal diameter. So you want 2.25" but even if you ordered 2.5" an exhaust shop would be able to make it work. The magnaflow x-pipe cavity is the same size for multiple sizes the only difference being the inlets and outlets.

MajikTom

2011 C350, W204 M272 Exhaust Project

I must have browsed 1000 sites, setups, sound clips and read through most of this thread and others here on MBWorld, and have landed on 2 setups:
ARH Headers + Remus catback: Meisterschaft resonator delete catback:
Unfortunately, Remus is a gongshow and months of Backorder clients are going Meisterschaft. Also ARH isn't selling anything compatible at this time.

So here's my plan:
- MBH Headers
- MBH High Flow Cats
- 2.5" pipe
- Magnaflow #10791 X-pipe
- Either:
- Magnaflow 11386 Stainless Steel 2.5" Oval Muffler (just to tone down a bit, may delete this later)
or
- 2x Vibrant 1792 Bottle Style Resonator (just to tone down a bit, may delete this later)
- Meisterschaft 4x120x80 CO axelback
- Meisterschaft Glossy black tips
- Stage 2 Tune
- Jcsportline Carbon Fiber Rear Lip Dual Outlet Diffuser

Hoping for +100whp when done.

Feedback?

Stuntman Mike

Forgive me if I’m confused but I believe you’re asking about modifying a C350, so that’s what I’m basing my answers off of.

The two examples you mentioned are apples and bowling *****. You’re never going to get that C63 sound from a 350 no matter what you do.

Also, what is a “Stage 2” tune on a naturally aspirated car? Not being a jerk, I really am curious.

And lastly, you already have much more than 100 HP at the wheels. If you’re hoping to ADD 100 HP with those (or any) mods, it’s not going to happen.

MajikTom

Well...

• I know I won't get the sound of a V8 out of a V6, I'm looking for the tone, not the overall sound.
• A Stage 2 Tune on the C350 is a common tune done here in Calgary for C350's with a header. (Stage 1 is without the header)
• As for an extra 100 HP, I know I'm dreaming, but realistically, an extra 25-30 is likely the best I'm going to get.

So, with all that in mind, and weighing in the cost benefits, headers are only going to get me an extra 5-10 HP, so for $3,000 for the Headers and HighFlow Cats, it's likely not really worth it.

So I'm trying 2 different projects:

1) Secondary Cat and Resonator Delete2) Cat Back Magnaflow SolutionOnce that is completed, I'll try it out before doing the "Stage 1" Tune
After the Stage 1 Tune, we are expecting about 20 HP total increase

Stuntman Mike

A) You won’t come close to sound or tone. It’s difficult for other performance V8’s to get close to the sound (or tone&#128580 of an AMG. It’s more likely it’ll sound like a modified Accord. I’m not saying it will, but the possibility is greater for the M272 to sound like crap than good.
B) You’d need 2 headers for a V6, and I had no clue they were available in the aftermarket for the M272. Again, what is a stage 2 tune? Is it just fuel mapping and timing changes? I can’t imaging messing with the timing on a variable timing engine. I suppose it’s not impossible to squeeze 20-25 hp with good headers and crafty mapping. But it’ll be in the top end. At that point it’s up to you if it’s worth the cost.
C) 100 hp gain isn’t dreaming, it’s close to impossible, er, improbable and impractical actually. You would need forced induction and much more and would have to spend much more than the admission price of a well sorted C63 to get there. And even THAT’S dreaming. 😴💭

Now I do understand the Canadian C350 has 268 hp..? And all the exhaust modifications you listed won’t net you near 20hp, you’d be lucky with 5. I’m not familiar with many ‘tunes’ for that lump. I’m not giving you a hard time, it’s just not common to wring much more out of today’s non-performance, naturally aspirated engines. Now with many of today’s turbos it’s common, easy and relatively cheap to get gobs more power with just a basic tune. Shoot me a link to this tune up in Calgary that you mentioned if you could. I’d like to see what you’re seeing.
My opinion is.. make it sound how you like, look the way you want it to, maintain it and enjoy it! But if you have lots of disposable income ( or are a very disciplined saver) and don’t frustrate easily, more power to ya! (Not literally unfortunately &#128513

Garagegods

Anyone install a Magnaflow 11226 single muffler on a W204 with either single oval or dual oval or round tips? any issues fitting as stock replacement or hangers etc. is it something most muffler shops can do? any insight photos would be appreciated.

UPDATE: Just spoke with a muffler shop and they recommend keeping stock exhaust since the c250 is a turbo the back flow could effect the turbo in either lack of performance or damage to the turbo, any thoughts?

chilnviln

I have a straight through Flowmaster Outlaw 2.5" with 3" tip. I've had the Flowmaster Outlaws on my last five cars but this was the first turbocharged one and somewhat disappointing as I like my exhausts really loud. It is more noticeable than stock so I guess I'll just have to live with it.
I had the muffler replaced first and it was barely a whisper above the stock muffler. A week later I had the resonators removed and that upped the volume a bit more. I haven't noticed any performance gains or drawbacks to changing out the muffler but it is only a 200HP turbo 4 cyl.

Flowmaster Outlaw 2.5"

3" slant tip

resonators deleted side view

resonators deleted rear view

Garagegods

Thanks for your experience,it really helps and to see that you had no real changes in performance or sound. I put an Eisenmann on my slk 320 v6 on another car and was considerably better sounding not much performance change and the price was $$$$$ i have been reading about other using the magnaflow 11226 and getting a sound that im liking close to my eisenmann and much less $$$. im still on the fence if its worth it? and i have concerns about the change in turbo back pressure or ruining the turbo

chilnviln

When I first replaced the muffler the only thing I gained was a lighter car as the OEM muffler is heavy, no real sound or performance improvements. there is a noticeable change in sound only after I removed the center resonators, and then it really needs to be above 4000RPM to enjoy the sounds but still no notable performance. Does not sound like an Eisenmann but better than stock. I've had this muffler on non turbo 4 cyl cars and they were loud AF no matter what RPM, maybe just the nature of a turbocharger. I was hoping for an Eisenmann when I had a V6 C300 but I couldn't justify the price at the time and there is nothing available for the C250s. You would think Eisenmann or Akrapovic could've done something with these cars.

Garagegods

I hear you about eisenmann at the time I had money to burn that was quite a few years ago my slk was a 320 manual transmission and sounded great! I’m finding same thing not much out there for a 250 turbo. Not sure if it has anything to do with turbo requirements? I found what looks to be next best thing to the eisenmann is the Meistershaft about half the price of eisenmann Still way more than the magnaflow. Megan Racing has some interesting mufflers not sure if those are
more volume than I’m looking for. Mine is a coupe and I’m finding what works for a Sedan won’t work for a coupe not sure why that would be? Anyway thanks for entertaining my quest!

chilnviln

You're welcome and good luck with that muffler.

kaantoker06

Hi, I recently owned a 2012 w204 fl and i am converting it to a c63. i have some questions about exhaust. do i need backpressure for my exhaust system? i am currently thinking to start a downpipe project, i will not remove the cat. i have some questions but i couldnt find any answers.

Garagegods

I am wondering about the turbo on the 4 cylinder since I’m learning the turbo is sensitive regarding the turbo back pressure and actually loosing power if changed. If yours is the 6 cylinder don’t believe it’s an issue. There are some YouTube videos by a guy flex that has done the mods without problems. Hope you get some info

IcedChai

Hi, a first-time poster on the forums I have a 2011 C300 Sport and did a resonator delete with an X-pipe install (Magnaflow 10790) about a year ago. 4 or so months after that I did a muffler delete to chase the louder, deeper sound, but I have a lot of highway driving coming up soon, and will not be able to handle the drone in the highway for that long. I saw the videos of the Magnaflow X-pipe and Muffler setup already, but none of them testified well to the amount of drone I'd get with that setup. I've heard mixed opinions regarding the amount of drone with Magnaflow Mufflers and an X-pipe, and I wanted to set the record straight.

So my question: Will installing Magnaflow mufflers with the X-pipe cause excessive drone at highway speeds (around 2.3 - 2.6k RPM), or is installing the stock mufflers back the best way to go? I love the volume and the tone but it's not worth it for my sanity ha-ha.

Thank you!

ap10046

I will chime in, if I may.
I had a PFL 204 with the 2.5 M272.
Did all the above with a Eurocharged tune, custom made airboxes, K&N's...
No matter what I did, it sounded crap.
With short tube headers, Magnaflows or Armytrix ((Long story) back boxes with 2.5" piping front to back and de-catted, an X-Pipe (up front and at the back in turn), there was this horrible "moan" followed by a howl (more painful than baleful) above 3000 RPM. It was actually embarrassing it sounded so bad.
Chucked everything away, stock mufflers, the Eurocharged headers, just decatted, Sounded best like this.
I also think I lost a chunk of low end torque.
YMMV