Hey Mercedes people. I have recently had ARH headers and the full ARH catback installed on my 2012 Sedan. A shop did the install that has done many VRP header installs but never a ARH install. I expected that the install would go smoothly but it had some bumps.
I should also add that at the same time I had Creative steel engine and trans mounts installed too. I also recently powder coated my wheels and painted the calipers and needed to install 3mm spacers with 3mm larger lug bolts to stop it from rubbing. All of this work was done at the same time. Anyway the shop complained to me that it was one of the worse header installs they had ever done and that to get the headers and catback to fit together was also a nightmare. They said that the VRP ones were much easier which left me speechless to say the least since these cost twice the price.

Everything is installed but the fitment isn't great. On the driver side of the car, the headers and exhaust piping by the cats are almost touching the frame, on the left side it all hangs lower and one can see it is not even. The shop said there is nothing that can be done about it because that is literally how the headers sit on the cylinder heads. It is not the end of the world but why the Frick would it not line up evenly? The whole exhaust for the most part is closer to the subrame/heat shielding then I would like. The lower section where the mufflers are is actually rubbing on the heat shielding causing a vibration, especially the right side muffler tips on my Mode carbon diffuser which is causing the worst vibration by far. I paid almost $7k for what i thought was supposedly the best or one of the best quality header and catback systems out there so why is the fitment so bad? I am not blaming ARH because I know many of you are happy with your setups but I don't know how many people are using their catback system attached to the headers and can comment on their fitment. Is it possibly the creative steel mounts causing the fitment issues? I am also getting a vibration/grinding - through the gas pedal but only if I put my foot down and give it some juice. I am not sure if this is from the mounts, the 3mm spacers or even from the exhaust possibly? I did have my wheels aligned and balanced and that did nothing. Right now I need to figure out how to approach this. I can't go back to the shop that did it because they spent many hours extra trying to get the fitment right and said this is the best they could get it. Do I go to an actual exhaust or fabrication shop and get them to mess with the fitment? We were also not able to put back the support brace or whatever this other thing is (see picture below) I assume it's okay to have these uninstalled long-term?

I love how the headers sound and I feel a definite torque improvement and am working with Barry on here to get the tune updated, but I just am disappointed that I waited so long for these headers and catback and the fitment is subpar and am getting this unknown vibration. I could use some help/suggestions in figuring out what to do next? Thanks.

 

I've installed both and don't recall an issue with the arh. It is fairly tight under there and I think most people put spacers if they reuse the aluminum cross support as most headers hit that. Also there is usually a fair amount of movement post header And you can move the exhaust a surprising amount by twisting. Couldn't tell from your pics exactly where you were rubbing into issues, but as the shop is fairly experienced it shouldn't be down to install error.

 

right now the right muffler is rubbing as well as the exhuast tip on my diffuser causing a vibration. I might see if this can be adjusted further, shop didnt seem to think so but they dont specialize in exhuasts. I am also concerned the right side cat is close to rubbing but so far I havent felt vibrations there. I'm most concerned with the gas pedal vibration

 

Ok yeah the muffler should have enough range of motion to get it to sit right. It shouldn't have moved the back section putting the headers on. The front area is tight especially if you run cats as long as you have enough space it isn't hitting it will be fine. The pedal vibration is probably from the motor mounts, I went with the race version of the ece ones and there's a decent amount of vibration now (only at idle )

 

I don't get any vibration at idle, it's only when I REALLY step on it and after driving the car around the whole of today it's also not all the time that this is happening so I don't want to overreact. I've just never felt vibration in the pedal before but maybe it's normal with stiffer aftermarket mounts. I am thinking I'll take the car to an exhaust shop and see if they can adjust the muffler to stop the vibration, if they cant then maybe I can bend it somewhat or trim my carbon fiber diffuser a millimeter or two. Again maybe I am overreacting a little with the fitment too and should just accept that it is a tight fit and doesn't have to align perfectly. performance wise the car is feeling great but i'll see what happens.

 

Strange, when I had ARH headers installed we did motor mounts (OEM) too, just because they are right there. I now have a vibration in the pedal under hard acceleration too. It's very strange. I can't see any contact anywhere so it's a bit of a mystery to me.

I did have to use spacers on the cross member and shorten the ends. Without being shortened the tips moved from being flush to sticking out inches. The mounts were highly stressed to say the least, so we removed a couple inches. Aside from the ARH headers, the exhaust is stock.

 

Delete the non hub centric wheel spacers to eliminate any light cruising vibrations felt in the steering wheel. Invest in quality studs/nuts and hubcentric spacers. Revert back to Factory OEM mounts to eliminate any acceleration vibrations/shudders.

Have had my fair share of headers and will say none of them are perfect. However, VRP had the least fitment/exhaust leak issues not to mention the deepest growl and bark due to larger runners and tri y design, it should also be known the only system without an X pipe. From anecdotal experience all designs hang lower on bank 2 (driver side) despite new factory or aftermarket mounts. I have yet to see a W204 C63 equipped with headers with a true straight exhaust. One tip always hangs lower or is either pushed further out, even if it's mated to the unmolested factory catback.

To be brutally honest ARH took less time to install vs VRP (less room on tri y design). However, the factory motor mount heat shields had to be discarded on ARH, not an issue for VRP applications. No sweat since they appear to be Cerakoted. Without saying too much or stepping on anyones toes there aren't too many sporting the ARH catback and because of this they're minor kinks that still need to be ironed out. Don't ask me how I KNOW. Keep in mind it's the only true 3" catback on the platform so fitment is TIGHT. Contact Nick and he'll get you squared away once they're settled into their new facility. MEANWHILE Inspect all 6 rubber mounts off the exhaust hangers for any tears/stress cracks that could cause sagging for good measure.

BTW, the driver rear bumper torx-25 appears to be digging into the resonator when fully secured. Remove and replace it with a ziptie for the time being.

 

one of our customers was the first to fit this full setup a few years back. i recall he mentioned there were fitment issues and when contacted the folks over at ARH, they quickly resolved. I do not recall exactly if a new exhaust was sent over but i think it was, the fitment on the new setup was better, but due to the large 3 inch piping, it took some effort during install, had to leave everything loose, then tighten up while moving the system into place which locked it into place. after lots of tweaking, everything fit like a glove without issue i believe what was told to me.

 

The wheel spacers are only 3mm, they don't make any hub centric spacers for ones that are this small. I might revert back to OEM engine mounts are a later stage but right now I don't think the vibration is really all that bad. I did go ahead and contact Sal and he is helping me to see what we can do about the fitment issues, so will hope and pray we can get it right or at least so it's isn't touching the sub frame.

 

Almost anything aftermarket is going to have some fitment issue somewhere.

My MBH headers sit a little lower on the driver's side. I have a custom midpipe, and it was hitting one of the heatshield nuts on the passenger side. It looks like the lower side on your car is the passenger side? That would be the right, not the left.

Get under there and look for any contact between the exhaust and anything under the car, and fix each issue. Sometimes you have to bend stuff out of the way for clearance.

And do yourself a favor and put that chassis brace back on the car. It does make a significant difference in rigidity. If you have to space it downward a little to make it fit, it will be worth it.

 

Yes I meant the passenger side. I've tried to readjust it several times now and gotten it a little better but the vibration coming off the right side muffler is super annoying and obvious. I also don't see how I would be able to reinstall the brace by myself. I booked an appointment with a highly rated fabrication shop who says they can get the exhaust to fit properly without rubbing and reinstall the brace. Going to be quite a few weeks before they see me but I think it's worth it.

 

Could use some advice, I finally got an appointment at the shop I have been wanting to go too and have the car there right now. One reason is to try fix the fitment issues because I am still having vibrations and rattling from the exhaust. The other reason is i want this shop to build me a straight pipe section to replace the ARH 200cell cats. Anyway the shop has quoted me $2.5k to build a custom section to replace the cats between the headers and resonator. I had no idea it would be this high? Are they taking me for a ride or is this what custom exhaust work costs? They are also quoting me another $800 to remove the rest of the exhaust and reinstall it and dent it where necessary to try get rid of the vibration/rattling. I am not sure if this is worth it and could use some advice. Isn't there a cheaper way to do a cat delete?

Also can someone please tell me what this black brace component thing is and what it's purpose is for??? Does it go here?

 

$2,500 to cut the cats off and tig-weld a few inches of stainless pipe is pretty crazy. That should be around a $500 job for a nice tig-welded cat delete. They can also weld it at a slight angle to bring the mid-section down just a bit to fix any of the rubbing issues.

 

It's to fab a removable section with v bands so I can swap it easily. Here is the actual quote it does seem really high.

LABOR
$1,540.00

• fabricate straight pipes and install V-bands
• Modify Catalyst pipes and install V-Bands

PARTS
$1,000.62
QUANTITY
PRICE

• Vibrant Performance V-band Clamp, Stainless Steel, Natural, 3 in. O.D. Pipe, Kit
  6.0
  $825.90
• JMD Tubes Mandrel Bend - Stainless - 3" X 4" CLR - SS
  2.0
  $174.72

 

V-bands are nice but that's still too high for a simple cat delete.

To give you an idea my shop fabricated my 3" muffler delete axle-back for under $800 using all stainless steel piping and tig-welded.

 

That seems like a very good price for that work and looks good too.

 

The black cross brace used to bolt up to the stock down pipes but ARH did not make provision to use it and neither does any other header manufacturer that I know of. Mine is in a box on a shelf. The mid-body cross brace may serve a purpose if you track the car but otherwise you will probably be fine without it. It would be too much work to try a bend the pipes on my MBH header mid section to try to go over it, if even possible without ruining the pipes. To space the bar down low enough to go under the mid-pipes would put it at risk of contact with the road surface and possible serious damage to the underbody of the car. Mine is tucked away in a corner of the garage. That piece can cause some very unpleasant interference with the exhaust.

 

Without revealing too much...Are you in a very expensive state?

As far as I know ARH sells a catless setup...maybe try and contact them and just see if you can perhaps pay a fee to swap for de-catted pipes?

Probably cheaper than rebuilding the wheel, shops are insane these days with everyone seeing all these silly youtubers/instagrammers and those god awful FF movies so this is surprising and also not in the same sentence.

 

I don't want to wait the 10 weeks it would take to likely go through ARH. I spoke to the shop more and they came down on the price and told me that was only an estimate and would only charge me for the actual time spent. I really hope I don't get screwed over here but it looks like i will definitely be paying more then I expected. When I went back to the shop today they showed me something very interesting which they also claim is causing my vibration/rubbing issues. The section right before the resonator is actually quite movable and somewhat loose even when fully tightened. The clamps don't seem to be doing a good enough job there, plus with the dip in that section and the way it is structured it is pushing the exhaust upwards downstream and this is causing it to rub and also the fit is causing the exhaust to move too much once heated up and i am busy driving. They are suggesting to create a straight pipe section over here and weld it to the pipes where the 4 clamps are thus eliminating the clamps and the dip section. They claim this will push the exhaust down a bit further down and eliminate the rubbing/vibrations. I will attach a picture of where I am talking about but i think this might be the way to go?

 

The problem is the sections immediately off of the headers aren't the same lengths before the first bend into the Y-pipe. It looks like ARH didn't account for this and instead mandrel bent in the same places on each side. This is pushing one side into the undercarriage. You can't just make the first section's lengths the sale now since it was made in their jig wrong.
Have you sent them these pics and what was their response? It's obvious one side is longer and the car isn't what's bent. 🤷‍♂️

 

I'm honestly so disappointed with their catback it has been nothing but problems for me. I called Saul months ago and he said he would help me find a shop to check the install and he never did. I will try call him again and send the pictures I think and see what they can do for me if anything I didn't think the section before the bend were different sizes i'll have to double check that.

 

I just had the shop check this and they said it's the angle of the photo and they don't see a problem.
Going to straight pipe the clamps section I was talking about and also create the removable cat/straight section with V bands. Hope it works out

 

very odd how that middle section is bent. bent in too many places and at the wrong angle/direction. it should have a bend there to clear which is bent in an odd fashion to clear the tunnel brace that seems to be missing in that picture? does that tunnel brace not come standard on the C63 like it does with the E63?

 

The shop said the same thing, they thought maybe it is even upside down. No tunnel brace was included no, we are seeing if we can put the OEM brace back maybe dent it to do so

 

Going rate for custom work in our area, J. Evan @RF cranked out 2 straight pipes with pie cut turn downs over $1K for my VRP setup. However, I thought I'd shed some photos since I'm sporting "nearly" the same system now

Make sure your X pipe isn't upside down, 02 bungs facing up towards drive shaft not down (ARH website photo for reference attached) Cross over pipes circled in blue need to be swiveled in similar fashion per photos attached for the tunnel brace to clear let alone create any offsets. ARH designed their X pipe/cross over pipes to directly bolt up to the factory resonators/catback if you ever decide to revert. With that being said the passenger side of the factory resonator is smaller (65mm) vs driver side (70mm), if vise versa your X pipe is upside down. New Factory OEM clamps will serve you better than the ones provided so cross over pipes don't swivel around once warmed up

​Factory clamp PN's
A0004901441
A0004901541