Tooken

I have the M157 Biturbo.

I'm on the fence here and need some opinions here. I was thinking of going with high flow downpipes or catless downpipes + renntech's lowest tune option. I don't need explosive power from tuning yet but I HAVE to open this exhaust up more because it's just too quiet idling and low RPM's. There's tons of corvettes and mustangs around me that sound good because they have exhausts installed and so I feel the need to show off the gloriousness that is the AMG. This seems to be a solid choice to keeping the deep growl of the AMG as heard in . I would leave the muffler and either keep resonator stock or modify depending on how much the loudness increases with DP's.
Option 1:
- May affect warranty (Maxcare)
- Tune could cause issues
- More expensive overall
- Wife hates racecar fumes (Replace wife?)
+ Louder, faster, more fun
+ Sweet smell of racecar fumes

The other option is to Resonator delete + muffler delete (would be a straight pipe from exhaust shop), so I can still enjoy my warranty and increase in AMG noise but worried that it'll sound like crap. Here's an example and it doesn't sound too bad. . The pops don't bother me too much and the exhaust note still sounds decent to me. Here's one driving off .
Option 2
- May not be as loud as I want it to be
- Lose AMG sound more?
+ Cheaper
+ Less chance to affect warranty (Maxcare)

I've been following kennyd a bit on youtube and in his forum posts. I had seen that he got some downpipes from Alibaba but not sure if he's car is tuned with high flow catted downpipes. I read another one of his threads with his Eurocharged tune issues, so I'm skeptical about tuning even though I've done it on previous cars. I guess I'm more attached to this car. Definitely looking at long term here.

Another question I had was why is the tune absolutely necessary with catless downpipes? Is there any long term risk of going high flow catted DP's or catless DP's without any tune whatsoever?

Thanks for the help! I've been scouring the forums looking at tons of posts so there's some things I haven't seen answered directly.

Tooken

And honestly when listening to both clips where they take off, it could just be camera quality but the first one sounds good and audio seems clearer. It also sounds louder, but I feel like the 2nd clip sounds very close in exhaust tone with some of those pops. I'd prefer no pops but at the same time, it doesn't bother me that much.

AngryScotsman

This may come off as purist BS nonsense, but if you want to sound like a corvette or camaro... buy a corvette or camaro.

Tooken

No worries. I did ask for opinions after all. So for you, is it an issue of loud exhausts like Camaros/Mustangs/Corvettes/Chargers or you just don't like the idea of modifying the exhaust at all? The downpipe seems to retain a loud of the authentic AMG sound still.

Rehabguy

As far as I know, through reading this forum, Kennyd is NOT tuned.
Going Catless without a tune will definitely result in CEL. I do not believe I read this here... but, seems like some believe that power might be pulled when CEL is on... maybe I read that on a Corvette forum?...
As far as opinion on the choices you have offered, honestly, I am not a fan of how the M157 sounds w/ Res + Muffler delete. As some here might have said before... it makes it sound like an old Dodge truck.
The M156, IMO, sounds better by comparison (straight piped) Check out SICKSVT's vid: (He is also cammed though)

Tooken

As much as I love the sound, it's way too loud. I wouldn't mind just going from the stock resonator to a straight pipe and keeping muffler and downpipes stock but I'm not sure if that's going to be much louder than stock. Hard to tell with videos if it's that much louder.

So you like the sound of the catless downpipes more on the first video I posted or nah?

AMGfifty5

Have you looked into installing an electronic cut out? Cut out plus resonator delete. I used to have no muffler and it was too loud for a daily imo.

Tooken

I wouldn't mind just doing a resonator delete and buying an aftermarket muffler that retains the stock sound but louder, I just have no idea which muffler would be like the stock AMG one.

I was thinking having no muffler could be too loud but then just doing a resonator delete with stock exhaust would be too quiet. I haven't but where in the exhaust would the cutout pipe/valve be welded or are you talking about adding an aftermarket muffler that already has a cutoff valve?

Tooken

I've never seen or used cutouts but I assumed they were just exhaust valves, but when I searched online for examples I see they put the cutouts right after the downpipes which would bypass the resonators and muffler completely. Is that how they're supposed to work?

Tooken

I found one with cutouts placed below the downpipes.

Rehabguy

Yes, I agree. The video I linked to you... I like how it sounds but it is just too loud. Aggressive as heck though.
Some have reported that resonator delete only adds a "little bit" of volume.
I like hearing the turbo whistle that comes along with the decreased restriction of "catlessness"... but, someone also reported disliking the sound of the S212 with catless DP at certain ROM range (They added, "Had I known, I would have left the exhaust stock. Not worth the 10-5HP"). Catless is a moot point for me anyhow. I live in the socialist state of NY.

AMGfifty5

I have resonator delete with stock muffler down pipes and it get loud only when you get on it

Tooken

Did you end up going straight, x, or h pipe?

AMGfifty5

stock

Rehabguy

I am sure he meant to ask "what did you replace your resonator with, an H, X or straight pipe?"
Also, assuming you meant you retain your stock mufflers.
I'd like to ask; Catted or Catless DP?

Tooken

Correct. I wanted to know if the resonator delete was replaced with H, X, or straight pipe.

AMGfifty5

sorry replaced with a straight pipe

I.T. Guy

I'm one of the ones that hated going cat-less. The smell is terrible, the sound is too loud WOT. The Turbo noise and exhaust sounds at low speed and part throttle are heaven, but then the smell hits me. To me going cat-less was not worth the straight-piped RAM 1500 sound at WOT for "10-15" more HP. Some days it makes me giddy but most days it's too loud and embarrassing. When I floor it on the highway I need to blend in a bit more, I hate trumpeting "HERE'S THE *******! RIGHT HERE! YEP! Everyone get your cell phones out and dial 911!"

Here's another sound clip for you - BB intake, Kooks catless


Here's some turbo noise just crusing around in comfort:


Here's driving around more and merging, some down shifting on the offramp:


Here's under a bridge:

I.T. Guy

My theory - no proof - is the resonator fixes droning. The loudness will probably stay the same.
The Mufflers don't really muffle all that much either, KennyD did a video on that, seemed like a ton of work (Thank you Kenny!):


If it were me I'd go for downpipes with high flow cats. If you can get the stock -> cat-less sound jump to about 50% of what that jump is, IMHO it would be perfect, without the stink.
Or live close to Kenny and get him to modify your mufflers

This is all very personal and subjective! Just like listening to speakers. Some people LOVE speakers that make my ears bleed. LOL. It's all good, I just buy speakers *I* like.

Good luck!!

Tooken

Do high flow cats throw CEL's still?

Tooken

Thanks for the videos! I want to avoid downpipes for now. I know the stock ones are pretty squished/restricted. Main reason is I don't want to tune or have a CEL light on permanently for warranty reasons. I think modifying the exhaust past the downpipes wouldn't have much issues with warranty...or at least I don't feel concerned about it as much as I would with a downpipe/tune or no tune.

Trying to find the right mix of loudness and sound but harder to determine since I don't see any E63 AMG's driving around ever, let alone have an exhaust modified.

Rehabguy

I was referring to YOU

Thanks for taking the time recording, uploading and linking all your vids! FWIW, I don't think your car is TOO loud with the Catless DPs. But, like you said, it's all subjective... plus, the videos might not be reflecting what it really sounds like when you are IN the car.

I.T. Guy

Yeah and all the YouTube clips in the world are nothing like real life.
The stock cats and pipes are actually really good - people are in the 10s on them no problem 1/4 mile wise - another reason I wish I just left them alone.

Maybe just try a cutout? Take off your mufflers and see what it's like! I have a feeling the turbos and cats and resonator etc. quite down the car enough it will be "fine" if you like the sound

Tooken

I'm leaning heavily towards a electronic cutout so I can be courteous of neighbors on start ups in the mornings. Now I'm just trying to see if it's better right after the downpipes or right before the mufflers. This video cannot just be cutouts. The owner said they bought the car like this and they have to have downpipes or something. The second clip the guy tried to mirror the first video but it sounds different.

First Video (Sounds like has downpipes) but says in comments cutout is just below the downpipes. Can definitely hear the turbo whistling more.

Second Video (Where guy tried mirroring the same setup) but says it sounds different. Barely hear the turbos.

Could just be camera quality but first video definitely seem to have better audio.

billvp218

I have Weistec mid-pipes and downpipes, and don't have a bad smell, even with the top down in my car.

I agree that the sound is too loud WOT. It's okay with top up, radio on, but the true sound that others hear (like I hear when top down, radio off) is way too loud. When I'm at 50% throttle, people probably think I'm flooring it. I wonder if another muffler could be added.

It is better for turbos to have a free flowing exhaust, but all else equal I'd take the stock sound. Low throttle new-sound, full throttle stock-sound would be great.

edit - added PLM 200-cell high-flow cats, and the sound is much better (still aggressive, but no longer crazy)