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I am 2 steps from ripping it off throwing it in the trash and either building a custom one or using the M137 one and modifying it. BUT I am also intelligent enough to see that they have never changed it, all the way to the 2017 M279 engine it is still the same part#! What the hell. If you look at it with your eyeballs you cant help but think it has to be a terrible restriction, it has to be shoving way more air down the middle cylinders and starving the back ones causing an imbalance of fuel ratios per cylinder etc.... How in the hell does this thing work as good as it does I cannot comprehend it, every high performance engine i've ever seen in my entire life would never use an intake manifold that looks like this. Even carb vehicles from the 40's use better intake manifolds. Someone explain to me why I should keep this brick in my engine bay.
Has anyone flow tested the intake and heads? I would not be throwing anything away unless they have and even then I would want flow numbers in boost.
Keep in mind the engine runs with 22PSI in full boost, at that level you could use nails for valves and straws for intake runners and still not be starved for air.
Yes, the intake manifold looks terrible, but there's not enough space for ANYTHING in there. I would focus your attention on the exhaust manifolds. Even heavily tuned motors use the stock manifold, but the exhausts are well known bottleneck.
Nick
Last edited by Welwynnick; Jan 7, 2017 at 05:03 PM.
With an air to air intercooler there is plenty of space, the water to air could even be relocated easily. If you don't care about A/C or ABC etc you can make a lot of room. I refuse to believe that intake manifold doesn't cause an imbalance that the ECU has to correct for, those middle cylinders have to be running lean.
22psi doesn't mean ****, think about it volume wise, 22psi through a straw is alot less air than 22psi through a fire hose. Look at any engine on the planet making 100hp per liter none of them use such a ****ty intake manifold, this engine should be putting out 600hp on 10psi not 22psi. Any other 6.0l engine like a LS Chevy V8 for example can do 600 easy on low boost. Mercedes obviously tuned this engine for luxury low end instant torque.
Look at the non turbo M137, it uses the same size throttle body as the AMG M275 and that intake manifold is glorious in comparison, why? Because they didn't have boost to make up the difference and didn't have the space constraints while having to retain all the other creature comforts and remain hidden from the outside view (like an intercooler through the bumper). I refuse to believe this intake manifold is worth keeping when there is an easy swap to be made for those of us that are looking for cheap speed instead of luxury.
As much as these cars have depreciated they are begging to be cheap drag racers vs having to build a 2JZ which costs $10000 on its own and god help you if you want to put it in a mk4 Supra which is anywhere between $20k and $60k.
I am 2 steps from ripping it off throwing it in the trash and either building a custom one or using the M137 one and modifying it.
BUT I am also intelligent enough to see that they have never changed it, all the way to the 2017 M279 engine it is still the same part#! What the hell. If you look at it with your eyeballs you cant help but think it has to be a terrible restriction, it has to be shoving way more air down the middle cylinders and starving the back ones causing an imbalance of fuel ratios per cylinder etc.... How in the hell does this thing work as good as it does I cannot comprehend it, every high performance engine i've ever seen in my entire life would never use an intake manifold that looks like this. Even carb vehicles from the 40's use better intake manifolds. Someone explain to me why I should keep this brick in my engine bay.
If you are trying to use or copy the M137 setup where do you plan to fit the intercoolers that sit above the valve covers? There really isn't space without doing some major relocating. Also, maybe there is a direct correlation between more air getting shoved in the middle cylinders and the restriction on the turbo manifold on those same middle cylinders. If the air can't escape easily, it may need a little more help getting in. I'm sure MB didn't take a step backwards with the intake, despite it being a bit less elaborate it seems to be balanced with a nice power curve. Besides the space was needed.
If you are looking to make some more power, focus on what can help the restrictive intake manifold and make a set of custom intake tubes. Reducing the restriction on air "IN" and air "OUT" (with catless downpipes) will allow the car to breathe much better.
When comparing power on LS motors with much less boost, you need to take compression into consideration. NA motors with higher compression can't handle higher boost but can make decent power with even 8-10 lbs. A motor built for forced induction typically is designed for it with lower compression. The higher compression M156 motor makes a ton of power with 11 lbs of boost when we are are double that at peak.
I think your idea would be a great help in making power, but I still feel the turbo manifold remain the biggest restriction. Then tuning becomes the next biggest limitation/ nightmare.
Our engine is inefficient period end of story compared to engines with half the displacement making the same power on the same boost. A LS with the same compression or a 2JZ or a B18 or a K20 or anything else really will make more power per liter with the same compression and boost. I'm ditching the stupid water to air intercooler setup, so space is of no concern to me, saves a **** ton of weight and stops heat soaking, air to air is the best unless you're dumping ice in a chiller tank even then it is a lot of weight vs just putting cryo tubes or dry ice on an air to air setup. Less electrical draw on the alternator too.
Air intakes don't really mean **** when you're talking the tiny k28 turbos we have, sure they add some power but why waste time trying to build around these turbos when they really need to be ditched along with the garbage manifolds. Stick a AFPR on it bigger turbos better intake nice manifolds and a tune I'll be blowing transmissions in no time lol. But I'm also going to gut the car so I'll have a bunch of interior pieces for sale. For $12000 you can't get a better half mile drag car imo.
Have you heard a M137 engine vs the M275? These **** manifolds make our engine sound like a pushrod V8 with a hint of V12 whereas the M137 sounds like a real V12 and the only difference is the manifolds and a little more compression.
Our engine is inefficient period end of story compared to engines with half the displacement making the same power on the same boost. A LS with the same compression or a 2JZ or a B18 or a K20 or anything else really will make more power per liter with the same compression and boost. I'm ditching the stupid water to air intercooler setup, so space is of no concern to me, saves a **** ton of weight and stops heat soaking, air to air is the best unless you're dumping ice in a chiller tank even then it is a lot of weight vs just putting cryo tubes or dry ice on an air to air setup. Less electrical draw on the alternator too.
Air intakes don't really mean **** when you're talking the tiny k28 turbos we have, sure they add some power but why waste time trying to build around these turbos when they really need to be ditched along with the garbage manifolds. Stick a AFPR on it bigger turbos better intake nice manifolds and a tune I'll be blowing transmissions in no time lol. But I'm also going to gut the car so I'll have a bunch of interior pieces for sale. For $12000 you can't get a better half mile drag car imo.
Have you heard a M137 engine vs the M275? These **** manifolds make our engine sound like a pushrod V8 with a hint of V12 whereas the M137 sounds like a real V12 and the only difference is the manifolds and a little more compression.
When comparing HP per liter, lets not forget the potential of the 30 year old GNs. The one thing all the other platforms have in common is software that can be easily tuned. The same cannot be said for the M275. It's easy to apply the same proven methods from other platforms and think of how well they would work on our cars, but find someone to properly tune the car, it's yet to happen. Look up some of the bigger turbo builds, they all had issues getting through the gears. The ECU and TCU are not on the same page.
You can't be so bothered with the design. It was a production car with more power than others for its time. It was designed to be quiet. The turbos and cats really make the car quiet. It takes on a different personality when removed under WOT.
You have the heaviest model M275(except the Maybach) to try and make a race car with. The other models you speak of are over 1,000 lbs lighter. Even if you are able to match the HP per liter, the extra load and weight will destroy the weak drivetrain parts. Your tranny won't be the only victim.
Good luck with what ever you choose to do. I'm not trying to defend the design, but the hardware is the easy part. It would have been done by many if it was as easy. If you are doing a full gut and go with a stand alone you probably have a better chance. The tuning will be the hardest part.
I mean if eurocharged can't tune it then I'll just go standalone, at the end of the day it is still just a relatively simple internal combustion engine and the transmission has been used in 90x different cars one of which I'm sure has figured out a standalone controller for it. Toyota's for example you cannot flash their computers at all, so you HAVE to go standalone hence why I'm used to it.
If you look at the specs for the S65 compared to the CL and the SL I think you're a bit off on the weight, the difference is more like 400-600 from lightest to heaviest. The w220 is the cheapest by far and the most stable and the only one with 4 doors so it can compete in the much less saturated 4 door class, when you get into 2 door classes you're ****ed because then every super car on the planet gets in. Really the only difference between the S and the CL is a door and some wheelbase all the components are the same, the SL looks a lot smaller but it has the entire convertible top assy to deal with so it really isn't THAT much lighter the LSD it has is not that great other than that it is the same with less room to work on stuff and it easily costs double or triple as much and has probably been beat on more.
Eurocharged got a bunch of power out of dynodaddys cl600. Over 850whp. Custom turbo setup. Look it up, it's an interesting build. In the end he had tranny issues that were never resolved. Car ran a crazy fast 1/8th but the 1/4 mph was way off. I'm not sure if he ran a stand alone.
The weight reference I was making was compared to the Supras and LS motor cars. All the MBs are tanks. I'm sure the cts-v dominates the 4 door class with such large aftermarket support, but that starts to add up so why not be different with something cheaper. I get it, again good luck, it sounds like you you know what you are up against.
Thanks for the good wishes and sorry to get so far off topic, I was really looking for someone that knows how they keep the middle cylinders from running leaner or getting more power with these manifold designs, the same cylinders have a direct shot on the exhaust side too!
With an air to air intercooler there is plenty of space, the water to air could even be relocated easily. If you don't care about A/C or ABC etc you can make a lot of room. I refuse to believe that intake manifold doesn't cause an imbalance that the ECU has to correct for, those middle cylinders have to be running lean.
22psi doesn't mean ****, think about it volume wise, 22psi through a straw is alot less air than 22psi through a fire hose. Look at any engine on the planet making 100hp per liter none of them use such a ****ty intake manifold, this engine should be putting out 600hp on 10psi not 22psi. Any other 6.0l engine like a LS Chevy V8 for example can do 600 easy on low boost. Mercedes obviously tuned this engine for luxury low end instant torque.
Look at the non turbo M137, it uses the same size throttle body as the AMG M275 and that intake manifold is glorious in comparison, why? Because they didn't have boost to make up the difference and didn't have the space constraints while having to retain all the other creature comforts and remain hidden from the outside view (like an intercooler through the bumper). I refuse to believe this intake manifold is worth keeping when there is an easy swap to be made for those of us that are looking for cheap speed instead of luxury.
Looks don't mean **** unless someone has flow tested it, and it is the mass flow not volume of air that matters.
You mention Chevy. Chevy LT4 is currently making 650hp. That is a motor that came out 10 years later with an extra 200 CCs displacement, variable cam timing and direct injection. They also use a water to air intercooler and a "restrictive" intake with a twin rotor supercharger. I can say it is "restrictive" because Eaton actually publishes the performance map on it. At 9PSI boost and 5000RPM it is 70% efficient, I would bet the intake on the M275 is far better than that (albeit without a supercharger).
As much as these cars have depreciated they are begging to be cheap drag racers vs having to build a 2JZ which costs $10000 on its own and god help you if you want to put it in a mk4 Supra which is anywhere between $20k and $60k. I don'tthink these cars make good platform for a race car because they are expensive to modify, very heavy and there is a lack of aftermarket parts. That said if you want to build a dragster out of an S65 I would get rid of weight: specifically the interior and ABC suspension. Then chop off the catalytic converters and get some stand alone engine management software. Those things will get you a more than changing the intakeIMO.Regardless, good luck with whatever you try!
2JZ, 1000+ to the rear wheels out of 3.0L all day long has been done hundreds if not thousands of times, just as an example. And was designed early 90's, most Chevy and Ford and especially the Hemi V8's can make the same power as our cars with a carb and a turbo lol
This makes a great drag car because name another car you can get with 750+TQ stock and doesn't break the driveline stock for less than $15000. Weight is just weight, it can be chopped and removed all day for basically free.
I'd bet $1000 cash the stock turbo intake manifold flow and distribution is garbage compared to the m137 manifold. I don't know why you think these cars are expensive to modify, used parts are cheap and swapping the non ABC suspension in is not that involved or expensive. The only thing expensive to modify is the tuning but plenty of companies can dyno and flash whatever you want, or rip it out and go standalone.
I have an idea and some simple findings you might be interested in. On almost all platforms you will see guys increase the throttle body in size, this is nothing new. On MBs you see the 55 guys bump up to 82MM and some to even 90MM.
In our case it would require a bit of fabrication and probably custom intercoolers to allow for more space in the rear. If we were to add a short "T"off of the intercoolers and install a 90 MM throttle body in a vertical direction, then we could run a piece of pipe with an opening to the stock manifold opening and add another of equal size shortly passed the stock location. Almost looking like a downward "F". This would require relocating the voltage regulator and the I think a MAP sensor. Depending how fancy you want to get, you could cut a piece of pipe on an angle(similar to the single stock opening)weld it into place and connect with a silicone coupling. The benefit would be better distribution of air into the intake from 2 openings while only having to control a single throttle body for tuning.
Physically I think it can be done, but I'm not sure what kind of tuning nightmare it would become. It seems tuning always becomes the limiting factor when you get to a certain point with power.
After thinking of installing the TB vertically, I went on to see that is exactly how its installed on the Pagani Huayra (with a better intake as well). See below, along with a pic of a 90MM throttle body. They are pretty narrow on edge.
Psi doesnt measure the amount of air that is flowing through the intake just the pressure it is at.
To make it simple, do you think a big diesel engine's turbo is pushing the same amount of air in at 10 psi as a stock dodge neon srt4?
That being said the intake manifold pressure is what the whole manifold is at. Sorry if this seems to dumbed down. So if it's at 20 psi and the intake valve for cylinder 3 opens there will be a pressure loss. However at this time another cylinders exhaust valve is opening to help spin the turbo and compensate for the loss of pressure. This means no cylinder will be choked out if the system is pressurized, as long as the intake runners are equally in size not length.
Have some custom headers made to fit bigger turbos and with the right tuning and iats you will see big gains.
If you have any experience welding you could do this yourself.
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I'm sure MB didn't take a step backwards with the intake, despite it being a bit less elaborate it seems to be balanced with a nice power curve. Besides the space was needed. 
