Hi All:

In case there are still any V-12 owners out there that haven’t come up with an exhaust solution (to the exhaust note), I can contribute this:

This all started with a flat tire and this post:

https://mbworld.org/forums/s-class-w...ml#post8653729

I dressed-up my brake calipers... Before and after:


Then, I decided to add some rumble (and perhaps some power) to the V-12 with some Ebay mufflers. My thought was, the car is old enough that a little hot-rodding will not offend purists, and may attract more buyers, if I ever decide to sell...

Old vs New:



New look… Right is old, and left is new...


For some further info on the exhaust topic, start with this post:

https://mbworld.org/forums/s55-amg-s...aust-s600.html

There are some U-tubes, with sound, posted there, but here’s my attempt…

I had to cut out my bumper cover to make room for the twin ovals... The stock S600 outlets have some cut-outs, but this system needed more… I got some U-channel trim from Ebay for the edging…

I'm semi-happy to say, I didn't go overboard:

New pipe is basically straight thru... Looking straight down the barrel:


But, even with no pipe at all-- I started the car with the old muffler cut off-- there is not a huge difference. It seems the twin turbos basically act as mufflers! A point BenzNinja made in post # 10 in the AMG link posted above…

As said, "semi-happy", because this was a hell of a lot work, and about $1000 out of pocket...

Sound is a little deeper, on the outside, but nothing like the difference you would get with this mod to a normally-aspirated engine... The turbos Really do act like mufflers... as I had seen on car shows on the MotorTrend channel, where they run the turbo exhaust right out of the hood... Those are obnoxiously loud. But, I guess, just the run though catalytic converters, after the turbos, effectively deadens most noise... Which is a shame...

This is my third V-12 --BMW, Ferrari and MB--, and I've always been disappointed in the exhaust note, which is unique... You see, all V-12's, by the math and their shared design, produce exactly 100 explosions per second for every 1000 rpm. That means 100 bangs per second at idle, and another 100 Hz for every added 1000 rpm, e.g., 700 bangs per second at 7000 rpm, or like a V-6 running at 14,000 rpm!

Since I have only briefly rev'd the engine while standing behind the car, I'm not sure what the general public is hearing with this mod... much less at 6000 rpm… But, inside the car, it's barely discernible from the stock muffler… just enough to know it's not running a stock system anymore... And, after a few real-world runs, I think it’s enough to be noticed, but not enough to change the car’s character. It’s still the Dictator’s car… just hot-rodded a little…


I guess it looks cooler... mostly from under the car; where you can see all that polished stainless steel... Kind of a waste, but I didn't want ridiculous either...


Also, --even though it wasn't as easy as the aftermarket seller indicated, i.e., lop and swap-- I don't regret having done the job myself. I suppose like anything not made by the OEM, these things don't exactly fit right in, and it took a little engineering and improv to make it work. I feel better knowing "I did it" and not “Joe the mechanic”, with 10 customers waiting...

So, here’s the takeaway for V-12 owners:

In hindsight, what I should have done is: taken the car to a muffler shop, and had them do a "muffler-delete", using the existing curved pipes and exhaust tips... just weld in a short straight-thru pipe. I think the result would have been similar, and not too loud... Of course, I didn't know that until I had cut off my perfectly good exhaust... and, heard it for myself... Still, my mod looks cooler...

In fact, it’s my opinion, now, that deleting Everything (resonator and muffler) would probably be okay on the V-12!!! Here’s the S600 like mine (mufflers-- what I replaced-- not in photo):


And, here’s a 2008 S65 from Ebay:


Note, no X-pipe, and 1 into 2 muffler, basically straight thru from the cats-- at least that's what it looks like in the Ebay pic for the S65…

Caveat: this opinion only applies to the V-12 TT. The normally-aspirated engine, I think, might benefit from a TT exhaust, but no muffler would be too loud on an NA… No???

Finally, I have a couple of questions.

The S600 has a 65mm O.D. exhaust pipe. The “Top Speed” cat-back I bought has a 70mm O.D. pipe, and they expanded the flared end to about 75mm O.D.


That caused me a headache, and-- with everything else fitting and the claim that the aftermarket fits all S models— that makes me wonder if the S600 has a smaller diameter pipe??? Does anyone know the V-8 pipe diameter? A 70mm O.D. pipe would be about the right size to fit the 75mm flare in the aftermarket…

There’s an existing fallacy that reducing back pressure on a turbo produces less power. It does not, my research tells me. But, did MB “buy in” to that mistaken belief, and make the V-12 turbo pipes smaller than the V-8?

In that regard and theoretically, does a 16% larger exhaust pipe, coupled with one-into-two exhaust tips (two-into-four, total), translate into more power??? Even 5% is 25+ hp for the V-12… Hard to tell, but 10% would increase total power to over 560 hp and who knows how much torque???… Anecdotally, the 20-70 mph acceleration seems a lot quicker… I mean, it was no slouch before, but now it’s almost a rocket sled!!! Uncanny how such a big car can scoot so quickly!!! Or, maybe it’s just the placebo effect...

Semi-happy from South Padre Island... Mark

P.S...

Here’s something for V-8 owners: I have left and right side used V-12 mufflers for sale cheap! (See pic above.) You’ll have to cut out part of your bumper covers for the V-12 ovals, but I have the trim for that as well… Here's the normal S600 tips:


Keep in mind, shipping won’t be cheap, but if you're coming to South Padre Island, Texas any time soon, you’ll get a great buy… And, based on what’s been said in other threads, the V-12 mufflers may perk up the V-8’s sound. The idea being, the TT mufflers are more open than the normally-aspirated V-8... don't know for sure....

 

group b rallying were everyone (except one manu) went the route of turbo'd to death 2 litre 4 pots were only loud with the over run anti-lag fuel spitting bit to keep the turbos wound up - otherwise all turbos kill all the high pitches noises, turning the energy in to boost pressure

one went with an NA v6 and they rev'd like hell...


shame the aspect ratio is wrong on both videos - the photo before you play is correct on the top video, but as soon as it runs top one is squat and the bottom is too tall - bottom one shows rally boys drive differently to road racers....

 

This is my black one with just a muffler delete and then I cut the tips and added amg tips.






Now with the full S65 exhaust on my silver one, it's just perfect.
I think the exhaust tips look a little out of place with your bumper, but that's just my opinion.




The oem calipers are so small on the S600, drawing attention to them would make me question why a V12 with such small calipers. I changed to the full front and rear AMG calipers/rotors which was a simple swap with no modifications needed. Bought them on ebay, cleaned and stripped them and painted them. Very inexpensive and gives the car a completely different look.

 

OP,
Excellent work! My question is, why didn't you go with the full system from ebay? That couldn't have been much more then what you spent? Mine is a S550 and I went with the S63 system. Nice little rumble but not too crazy where it will draw attention. ( Have to make a video at some point ) As far as the tips go, I know you can modify the lower valence to one from S65 so your tips will look more factory like the ones above. Either way, if you are happy with the sound abd look, that is all that matters 👍

 

I love the song of the V12. It is a beautiful sound.

 

Is the exhaust restricted as part of the "this makes enough power, and the transmission is fairly stressed" program? Backpressure after a turbo does no one any good. I assume MB agreed.

Actually backpressure is never really good for anything. Lack of backpressure can be a symptom in an exhaust that has poor scavenging (N/A) but that's a byproduct, and not the cause.

 

Great input, guys:

Botus-- I think that’s it. The turbos kill the high frequency and turn noise into power..

Theoretically, counting the bangs per second -- and not accounting for other vibrations and resonances that impact what comes out of the exhaust-- here is what a V-12 should sound like at 6000 rpm:


And here’s what 3000 rpm (or, a V-6 at 6000 rpm) should sound like, 300 Hz:


I had a 240Z (I-6), back in the day, with headers, dual straight pipes and 4 cherry bombs. It had a bad-*** sound at 7000 rpm. Sounded like the I-6 XKE, but rev'd higher... You could probably use that exhaust on the TT and barely notice the difference…

WHPH28-- I used your posts in the AMG link ( post #1) in my research… Thanks.

As mentioned, this started with a flat tire, and while I was waiting on the tire, decided the unpainted calipers were fugly. So, I just did some touch-up with everything installed.



Real 2008 AMG calipers would be the way to go, but I wasn’t into that much work... Also, I don't know what to do about the single piston rears (other than go full AMG). I’ve seen some fake rear covers on Ebay, which may be okay for the cosmetics. Anyone tried those???

I have no complaints about the “small" calipers on the 600. I’ve opined about the single calipers on the rear, but I assume Merc knew what they were doing with the mismatch-- the car stops as quickly as an RX-8, which is no slouch... The 600, as equipped, has uncanny stopping power for such a heavy car… I like “cool" looks, but I'm more into function... (and minimal effort…) AMG calipers are overkill for me, and I’m more than a 1000 miles from any mountains and don’t have a "legal" Autobahn. (Don’t tell my car that…)

Doni01-- I also used your forum inputs in my research. I don’t have a lift and was working from my garage floor with The Wheel of Death and no welding capacity, so I didn’t too get too complicated. (Tech Tip: I used a 7" cut off wheel. Don't depend on your plastic eye-glasses for protection. I went with real wrap-around safety glasses after a spec of SS got in my eye! That ***** don’t rust and won’t go away-- all good now, but caused me a fright...)

My takeaway in post #1 is, turbo exhaust on the V-8 is good; V-8 exhaust on the turbo is going backwards… And, in hindsight, straight pipes or muffler delete is the way to go, but only on the turbo. I imagine, even used AMG S65 stuff is pricey and hard to find…

Kevm14-- That was one of my questions in post #1. Did MB fall for the myth that turbos like back pressure? They don’t. As you said, back pressure isn’t good for anything… Also, the V-12 gets the "ol faithful" 5-speed, not the 7-speed. So, I don’t think they were worried about the tranny… With the torque of a V-12 TT, who need 7 speeds anyway...

More puzzling is, 65mm pipes. The aftermarket, I installed, has 70mm SS expanded to 75mm O.D.-- like they were thinking the OEM would have 70mm O.D. pipe???



As mentioned, I had to make some mods to make a 65mm pipe fit in a 70mm hole… So, my question remains. What's the O.D. for the V-8? And, if it is 70mm, why did the turbo get 65mm???

Regards to All… Mark