Exotic-metal55

Just had a little fun cutting up a stock manifold and putting my handy mic to the flow areas.. First, it is amazing we can push 500 plus hp through holes this small. Those 50 year european emissions standards must be brutal! No wonder many members claim headers gave them their largest gains.

The stock manifolds, look kind of large to the eye but that is all there to hold heat in, keep heat off the motor and most of all to keep a tech from dropping a wrench and shattering the toothpicks we have for exhaust pipes..

Below is a stock manifold next to the tiny 1.42" ID pipe that runs inside it.. I taped a quarter over the stock manifold collector, just for reference.. Yes, all the exhaust flows through a center pipe that is 1.42 and then goes into a collector that is not much larger than a quarter.. 1.62" to be exact..



Below: Stock collector ID. You can see the light tan sleeve inside the manifold.. The heat and back pressure on a moded motor must be immense.




Stock primary inlet into manifold.. Large weld blocks about 20% of the flow and this port measures 1.42, some are as tight as 1.38..




What is really a crime, is that the exh. head port is larger than the manifold primary and the main tube all four primaries flow into.. 1.54" Below is a pic of the head port on my extra set of heads..





No secret, but I have been trying to find the right kind of headers for my body style and has been a major hold up on my build and even tuning.. Just hard to tune with so much boost and air going in and no way to get out! Jerry @ Eurocharged stepped up to help me out and is having a set of custom made high power/high flow set of headers .. Jerry even offered to come over and help get them on, so we can make the Texas mile and HRP before our desert heat sets in..

chiromikey

as always my friend, thanks for the research and then sharing with the rest!

LB63

Those headers don't befit a performance engine.

acb

now if only headers were even vagually reasonable in price...

RenntechE55

Hey exotic what headers did u go with?

BenzoBoi

Wow...nice write up!

blackbenzz

Haha those manifolds are a joke. Nicely done

prodigymb

stock manifolds are in fact a joke. exotic sorry i didnt get a chance to measure my EVOs for you before I sold the car ....

jicl55

Just curious..... on the short piece of pipe that connects the headers to the primary cat, how big is that? If I remember correctly, I believe it is only about 2 1/4", if that. I remember (I think it was Vadim, back in the not too distant past) offering a piece that connects to shorty headers (what I got) that was closer to 2.5" or something like that. Was thinking that would help open up the exhaust some more. Anybody ever try it or something similar? Does anybody offer something similar?

Sincity

What a crime! A tiny pipe within the housing itself!

jicl55

Yeah, and that the CL500 headers=CL55 headers (and E500=E55 headers). Seems like AMG skimped pretty hard right there......

dyno

very well done Exotic

it tooks about 5 years but at last that "Pulcinella secret" of real sizes has been unveiled

930chas

That is some great info! Unreal how much the stock ones suck.

SterlingE55

Brooke, your research always makes want to spend more money on my car! Haha but seriously I want LTs.

Exotic-metal55

Eurocharged is making a custom set of LT`s for me but still have to test fit them on the CL body style.. These will , well lets say be LARGE!

Not many parts for the CL, so as many of you know, I had to custom make or have made most everything on the car.. Well, the few mods I have.. I have spent 7 months of re-search and trying to get a set of LT`s but no luck on the flow parameters I want or gurantee of a fit.. I even gave a large deposit to a well known local Chasis (comp eliminator car builder) to custom make a set and he basically F-ed me out of it.. Still have to deal with that..

No problem bro, I think they are 1 5/8" anyway.


That short pipe is basically 2" od and with sloppy bends in it, even less flow than it measures.. Changing this would help if you have shorty headers and 2.75 would be the best size.. On a stock mnaifold, you may not be able to measure any gains from this, as the manifold is just to restrictive.. If I had the Evos, I would cut thier small collector off and just weld a 2.75" pipe onto the end and to the first cat.. This would help any shorty out tremendously..

MB_Forever

Why does Mercedes/AMG go through all the efforts of creating an incredible engine, then slap those manifolds on.... they seem so under-developed for such a high performance vehicle I understand emissions are strict, but I'm sure there are much better designs that would still be legal

c32AMG-DTM

Cost issue? I understand that MB/AMG used the same exhaust manifold for all M112 engines (C240 up to C32 AMG); they likely did the same for all M113 engines?

suicidal4life

Should have titled this thread Truth Revealed! Why any headers are a must!

Obviously if you are going to upgrade it makes sense to go with good headers but looking at the cutaways of that stock mani it stands to reason that any header, even a poorly designed one, should show gains. Looking at how tiny the internals are its no surprise that even log style "headers" like the VRP Vadim style showed decent improvements. Even on my lowly E430 the stock manis (very similar to the E55K manis) are too restrictive for that engine. Its almost criminal that AMG went so small on the 55K.

Exotic-metal55

I would have settled for less boost to have the stock BMW M5 manifolds..lol http://www.m5board.com/articles/bmwm...italy/m118.jpg

The Corvette c6-Zo6 and Zr1 have some of the best stock manifolds I have seen.. They even have their own runners and a huge oval collector..

Thericker

That explains the awesome STOCK exhaust note on M5/M6...

My old C6 Vette had horrible stock manifolds, I upgraded to Kooks 1 7/8 w/X-pipe/ Hi-flo kittens, difference was shocking to say the least, in Sound & HP/TQ

X2Board

WOW!

Thanks so much for sharing. I know what my next mod is going to be, I was thinking pulley, but it would be a crime to run more boost with those puny headers in place.

LB63

If BMW and Chevy could do it I don't see why AMG couldn't unless they thought the motors were putting out "enough" power.

Those stock M5 headers look purdy

Those stock AMG headers look like something out of an economy car

Even the stock headers from the Mustang 5.0 of yesteryear look better except for the pinches (see bottom header):

TopGun32

after 7 years.. I think somebody can make shorty headers under $1k...

The old HEM's that our old friends at VRP were a good product but overly priced.