JRSJR65

The more I search forums and read different options the more confusing this becomes.
I have had installed (see signature). Kleemann headers and Mike's H-pipe. What is the best way to complete this from H-pipe back? Am I already as far as I can go for improved flow and max HP?
This is NOT my daily driver. Exhaust noise level is NOT an issue. I like it loud and don't care how loud if it gets me HP gains.
Is this a worthwhile option http://www.topspeedauto.com/index.ph...051&search=c63 ?

I know we have some real experts here and also a lot of vendors. I just want facts please, real numbers not a sales push.
Thanks!

Ezec63

Are you running the kleeman longtube headers or the kleeman shorty headers? What about mid pipes or X-pipe? Honestly i know you are running an H pipe so it would be a waste but an x pipe is a better option performance wise for our engines especially when fully catless the X offers more mid range torque and exhaust scavenging.

If your mid pipes are 3" like most of the manufactures than where those midpipes meet the stock resonator back is a restriction. The stock piping is 2.5 inches so the 3 inches reduces into this causing turbulence and interrupts flow. Also the stock exhaust piping has some pinches and crimps where the pipe reduces to below 2.5 inches in strange areas that will cause even more turbulence and be a big bottle neck from the velocity being thrown out by the headers and 3inch mid pipes.

Best performance option would be to do a custom 3 inch exhaust for max power kind of like the MHP race exhaust and add your own custom muffler boxes. That will be brutally loud tho !

What im doing is mating my headers/mid pipes to the Agency Power valvetronic exhaust. Its not a full 3inch but is 2.75 and mandrel bent with no pinches or flow interruption at all. It also replaces the stock resonator with a Siamese X-pipe which I already have with my MBH set up but the double X cant hurt Also gives me the option to close the valves and have the car quiet for the 20% of the time i want it to be. They have dyno graphs showing ~20 wheel gain on a car with headers already. Something to think about

farhadahmad

tell me about it. i got x pipe before seemed faster but sound super sporty sporty almost ricer. but when i was parked and reved it . SOUNDED LIKE A BEAST . but company who made that x pipe did ****ty job. it was rubbing like crazy. now i got Hpipe. sounds good but not loud enough. make straight pipes all way down?
i think im going buy a full exhaust soon. tho but HEADERS will do the job but so damn expensive

Ezec63

^ If you read the full post youd see he was asking how to make max power out of the exhaust system not the most obnoxious exhaust system in texas that would make honda civics with fart cans jealous.

Straight pipes all the way back on a V8 or any V engine is the worst setup you can run. In that scenario both banks of the engine would be running separate from each other instead of in unison to make max power together. Its very beneficial to have the exhaust banks meet to balance each other out (H pipe) and even better to have them smoothly mix as well (Siamese Xpipe) preferably as close to the exhaust manifold as possible but any X or H is much better than straight pipes. Not to mention the obnoxious rasp/drone straight pipes would have on this motor

Ezec63

The only way straight pipes would work in a V engine is if it were a straight pipe. As in both banks meeting after the headers in a Y pipe under the car and prob using a massive 4+ inch single exit exhaust lol but you would still have both banks meeting

VividRacing

Just get the Agency Power rear section with the electronic valves from me at the awesome MBWorld price and be happy with variable exhaust tones! Loud as hell or nice and refined when needed!

James@ACG

iPE rear section is the way to go... if you dont already have long tube headers and your trying to maximize power... you would be better off spending the cash for a set of long tubes as to doing the exhaust... just my opinion...

iPE also has a full header back system which includes the valvetronic exhaust system.

JRSJR65

So Agency Power rear section or iPE rear section? Comparisons? Owners with these on here?
I have the Kleemann LT headers and an h pipe. Trying figure what to do from there back to maximize HP and not worried about how loud it is. Having a valvetronic exhaust would be nice though

VividRacing

They are identical from what I've been told. I'll shoot you a PM with pricing!

Ezec63

Yes they are produced by the same company JIM exhaust. The only difference being the valve motors IPE has an auto button on top of the On/OFF of the Agency Power that can open the valves and shut them off according to your throttle input. IMO unnecessary as I know i will want it open 90% of the time and just shut it off when im cruising on the highway not worth the extra coin for the IPE system IMO again.

I got mine from vivid racing a few weeks ago just dropped the car off yesterday at the shop to get this bad boy installed. Great dealing with them and also have dealt with ACG in the past and they have been great as well.

VividRacing

The Agency Power system can also be wired to automatically open up with RPM signal also it's just a process to run the wiring

nietzsche

can i get a PM for IPE full exhaust and also for agency?

Girard@ACGautomotive

PM Sent for iPE

sales@eurocharged.com

email me at philip@eurocharged.com

i can quote you some agency power headers

Sincity

OP: I wonder how your H-pipe sounds? I have the Kleemann log manifolds with a MBH X-Pipe and the car is quieter than when it had the secondary cats. As far as the additonal torque the X provides, my butt dyno cannot really feel it.

kaunain13

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w204nyc

Does anyone know if you need to have the car retuned if you remove the primary and secondary cats?

C63-AMG

I was told you didn't, but it's recommended. Do you have CEL's now?

w204nyc

No I havent removed the cats yet. But I do get CELs from time to time mainly from O2 sensors going bad

Merc63

You want noise and performance, go with mhp long tube headers, x pipe and the stock cat back.

w204nyc

I'm looking more for noise. I live right in the heart of NYC so I dont get a chance to push the car that much. Only time I get to push it is driving to my weekend house in PA.

TTA850

Go for headers, I went with MBH headers x-pipe/no cats it sounds incredible and very loud - best part is the echo between the buildings and looks on peoples faces as they realize all that noise is coming from a Mercedes lol

VividRacing

I feel that headers are too loud with the stock exhaust, I really am a huge advocate of the valvetronic catbacks that are available and it just so happens that I can get you the best priced unit available haha

It's so nice to be able to quiet down the car when you get a chance!

TTA850

Yes it is obnoxiously loud, but I personally feel it fits the cars personality perfectly - only thing better is if the tuners could give it a cammed idle (ghost cam) for a little stoplight chop as Ford does with the new 5.0 Mustang.

That said with the car in C and driven like a human I find mine barely louder than stock - however in S+ and driven like an AMG it's pure bliss

w204nyc

I had a set of MHP header and never installed them. Even got a special license plate for them lol but I passed on them. Now i dont want to put too much money into it because I am still paying for school and purchased another car so figured straight pipe is a cheaper mod as oppose to headers