I have searched a lot and read a lot on this topic over the last week or so, but it seems to produce a mixed bag of answers/opinions. So the aim of this thread is to try to establish the facts.

So lets take for example my benz, its the C180k (1.8L supercharger motor) It currently has the standard front mounted intercooler, with the standard restrictive loop of piping from the supercharger to IC and from the IC to inlet.

Restrictions are mainly the muffler/resonator located off of the supercharger outlet, a smaller/reduced 90degree bend going onto the inlet/throttle body and possibly the cooling properties of the intercooler itself. (Not to mention that mercedes used flexible piping for most of the IC piping, which creates turbulent air flow)


So the standard cooler, to my knowledge its 22inches x 4.5 inches x 2 inches making a total volume of 198 cubic inches.


Now we must also understand that a turbo and supercharged car work very different! We cant just bolt on a bigger/more efficient intercooler and see 30-50bhp (for arguments sake) unlike a turbo engine.


The supercharged engine in my benz produces 0.6 bar or 8.7 psi (correct me if wrong)


My idea of upgrading the intercooler isn’t by any stretch of the imagination a new idea in terms of improving performance on a forced induction engine. My aim is to source and install a more efficient intercooler (bar design) whilst removing all restrictions within the intercooler piping loop. This means not going for the biggest intercooler money can buy, as this will increase the volume to such a level that boost will drop! However by slightly increase the volume and removing all restrictions I think it will improve charge flow and temperature whilst maintaining the current level of boost.


What I hope to achieve is, maintain the same levels of boost, reduce the charge temperature, improve air flow and possibly add a few bhp/torque.




So.... Does anyone have any useful information on this topic/subject area, or have you upgraded your intercooler ??


Opinions and thoughts are also welcome


Thanks, Moo

 

I am Very interested in hearing the Opinions on this Topic.

Subscribed.

 

Personally i propose to run a slightly bigger/better intercooler than standard, whilst removing all restrictions within the system.

So i plan to run a 22inches x 6.5inches x 2.5inches with full 2.5inches piping.

The aim by doing this is to maintain current boost levels but whilst cooling charged air better and removing all restrictions, therefore making air flow less turbulent.

What is very important on this topic is with a supercharger setup boost pressure is far more important than charge temps !! A drop in pressure will reduce performance far greater than and drop in charge temps can increase it !! (Which is why the biggest intercooler is not the best option as boost pressure will drop)

So the key is to maintain the same boost pressure but cool charged air better, couple that with no restrictions and im hoping to improve power across the rev range as well as improving looks

Couple my above ideas with a pulley..... (so an increase in boost pressure) and i personally think a good amount of power is there to be gained!

 

Step #1 would be to measure the actual inlet temperature and from that judge what the actual improvement could be.

On my C180 I have measured temperatures upward of 45 C during full load with ambient temperature of around 20 C.

A 100% efficient IC would thus lower the temp by 25 C, and since air density is directly proportional to temperature in Kelvin, the new air mass would be (273+45)/(273+25) a 7% increase. Given the right software (allowed air mass needs to be changed in the ECU) you would get a whopping 11hp on a C180K(*) and that's an *ideal* IC.

In conclusion, altering the IC is #4 or #5 on the M271 performance list

#1 New software (and repeat for all other steps)
#2 Pulleys
#3 Header
#4 Bigger Supercharger(?)
#5 Bigger IC(?)

(*) On stock hardware, with allowed airmass maxed, a C180K gives around 170 hp

 

Renntech made a FMIC for our cars, at least the M111 engine. Somone who had installed it, I believe, only noted a reduction in heat soak when it was hot out, not necessarily a gain across the board. It was also damn expensive to boot.

While I think it would be an interesting project to do some improvements to the I/C setup, I question whether it would really generate anything more than a minor increase, especially given the cost of something custom. But feel free to prove me wrong, I'd love to be.

 

I think the cost would outweigh the benefits especially on a car that is 10-11 years old. But then again the cost always outweighs, right Tommy?

I've thought about the intercooler but came to the conclusion that it isn't needed. If anything you will lose PSI.

Also thought about the engine swap. There was a wide variety but would run me about $4,000, I wanted to do it and I didn't have a spare car in the meantime.

Also thought about the headers, aren't made.

Pulley. Probably the best thing you can do to the M111.

Not a big believer in ECU tune ups. It can only get so loud.

Then I decided to save my money for a new/newer Mercedes.

 

Yeah, I think the days of a CAI/header/exhaust upgrade for $800 giving you 15hp are over, sadly. Or even getting a chip to a GTI 1.8T for $450 giving you close to 20, as another example.

Sh*t, I'll be paying $1,300-1,600 this week to repair rust in front of the sunroof on an area that I've never even seen on my car. How's that for costs exceeding any visual difference?

 

It will make your car feel younger. Kind of like botox.

 

It won't look like Joan Rivers, will it?

 

Not as good, sorry

 

Thanks for the reply


That is a very useful answer in providing facts around the subject. I do plan to measure both inlet temperature before and after the modification, I do expect to see a drop in the charge temperature on any given day during full load.


Your sums seem impressive as 11hp is a nice gain for just a cooler charge. However please remember I am not only focusing on a more efficient intercooler, as my original post states I am to remove all restrictions within the intercooler loop (muffler, restrictive 90deegree bend and the standard mercedes flexi hosing) which all cause turbulence to the charged air.


Personally I think this modification (if done correctly) coupled with a pulley will see a nice improvement of power across the entire rev range!


The car should make more power lower down, due to less restrictions and again it should flow better at higher rpms (not forgetting a colder charge) Providing the boost pressure doesnt drop (from running too bigger intercooler) a better, colder air flow around the loop should see these improvements.

Thanks for your reply also


Yes Renntect made a FMIC for the kompressor engines, however when looking into the intercooler size, in my opinion it was too big for these engines (which could explain why your friend only noted a reduction in heat soak when it was hot out) I also happened to see how much the intercooler was new, and wow, it wasn’t cheap. However here in the UK intercoolers aren’t expensive. For example the intercooler I plan to use (which I noted above in a post) is only around £60 so its by no means an expensive modification. I also know people within the motorsport industry who helped with my previous project, my supra (Although the benz is my daily driver I plan to make a few changes)


Again I personally think this modification is worth while is a suitable cooler is sourced, along with a more efficient running of piping.


I really hope I can prove a few people wrong along the way, dont get me wrong im not out to say I told you so or anything like that. I just personally see gains to be had!


Lets hope im right


This seems to be the main perception of upgrading the intercooler on these engines, however it all comes down to a suitable intercooler.


I hope I have served up some food for thought....

 

Does anyone know the standard size of the intercooler piping ?

I think its 2.5inch ????? (of course its smaller in some places)

 

Changing the intercooler isn't the only task. You will also need to redo some of the piping for it to work as efficient as you want it. You will need a shop at that point for the custom correct piping.

At that point you might as well induct compressed air but they already come with a supercharger...

Or better yet a bottle of NOS, most likely 50 shot. 100 if you feel lucky

 

Correct, and i am awear of this

I happen to be good with custom piping. On previous projects i used custom work by myself, as it means i can put things just how i want them (not to mention the best route for them)

 

As for NOS, the benz is my daily driver, which i plan a few choice modifications. No more than that.

 

Supposedly there are some off the shelf Ebay IC's...
http://www.benzworld.org/forums/w203...ooler-mod.html

 

with the m271 i think the ic upgrade works well. But i also have renntech pulley kit, so im sure it works a lot better if you have both. Heres a link to some pics of my ic upgrade:

https://mbworld.org/forums/4490549-post860.html

 

Yes, i came across this in my research its interesting tbh. Personally i will buy the intercooler i want and upgrade all piping to custo, but the ebay route is an option with this modification.

I also agree this.

Looking at your pictures it seems you only upgraded the intercooler itself, did you change any intercooler piping ? Or remove any of the restrictions ?

 

Found some interesting reading tonight.....

However most say (and i agree) that an intercooler that is too big will reduce boost and there power.... so how about this.....

What if a slightly smaller intercooler was used and all restrictions were removed ?? (On the previous concept) shouldnt a smaller intercooler with no restrictions yield more boost and faster into the inlet ??

(By more boost i dont mean the S/C will produce more boost, i mean less boost will be lost than even the stock setup)

 

I would personally just replace the piping with something less restrictive. Let's remember here that turbo setups and supercharger setups are quite a bit different.

Since a turbo is driven by the exhaust which results in heating up the pressurized air significantly which would be why a large intercooler is required so it doesn't heat soak. Superchargers are obviously driven off a belt. In this setup you just have the heat from the engine bay getting sucked in through the air filter and the heat in the engine bay heating up the supercharger itself (which is still a lot cooler than exhaust). With this being said, the heat in a supercharger setup isn't nearly as high as the heat from a turbo setup.

When I had my turbo Jetta, it had a very small intercooler and I would notice heat soak and a big loss of power on 90 degree days. My c230 I have yet to notice a loss of power on hot days.

 

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This is all very correct !! Which is why im considering a slightly smaller diameter piping too, instead of 2.5inch maybe a 2.25inch or even 2inch will be better suited. (this would be a complete custom piping setup removing the restrictions like the muffler and 90degree reducer within the intercooler loop)

As you have stated temps are not a massive issue ! Loosing boost is !

Also going back to my earlier posts which state a lose in boost cant be made up by a drop in temps (no matter how extreme the drop of temps is)

 

Been considering a few figures tonight...

Ok so lets investigate some figures.

- Aims of doing this
- Understand the volume of the stock system better
- Should help find a more suitable setup in terms of IC+piping

(For the purpose of ease i will quote all sizes/volumes in inches)

(I have used the principle that when people remove the supercharger muffler in the intercooler piping loop and the restrictive 90degree bend, they use 2.5" piping to replace them, so my calculations assume the stock IC piping is 2.5") I have allowed for a total of 59" of piping for my calculations. All figures are estimated.

Ok, the stock IC i believe to be 22" x 4.5" x 2" = 198" cubed

And 59" of 2.5" piping = 1158" cubed

So this means the car (My 1.8L M271) produces 0.6 bar with all restrictions in place and a total IC volume of = 1356" cubed

Now, most people use a big IC for looks and they believe bigger is always better. However most experience no gain or infact performance lose as there total volume of IC is more than likely double stock! Therefore losing boost pressure!

So, a very popular size IC for the M271 is 22" x 5.5" x 2.5" = 302.5" cubed

As you can see from the stock IC the dimensions are not much different, however its about 33% increase in the volume!

However we can gain this back in the piping diameter we use, for example if we use 2.25 inch piping (again allowing 59") we get...

302.5" cubed + 939" cubed = 1241.5" cubed (saving about 114" cubed over stock whist removing all restrictions and upgrading to a better IC)

Further to this, if we use 2" piping (again allowing 59") we get...

302.5" cubed + 742" cubed = 1044.5" cubed (saving about 311.5" cubed over stock whist removing all restrictions and upgrading to a better IC)


So, conclusions, picking a suitable size IC is only have the battle. Piping will/does have a massive impact on the boost pressure (even on 59" of piping)

Questions that arise from this...

- Is 2" piping too small for the M271 engine ?
- What boost pressure does the supercharger put out ?
- How much of this is lose by the time it gets to the inlet due to the volume and restrictions of the stock IC setup ?
- Will decreasing the total IC volume increase boost slightly ?

Thoughts and opinions are welcome

 

I wouldn't mess with the size of the piping. I'm sure mb thought this out when they designed it. As for boost pressure. Hook up a boost gauge to find out. I have an m111 so I don't know about the m271. I'm pretty sure you could tap off somewhere near the throttle body to find out post intercooler boost and tapping off the fuel pressure regulator will give you actual boost that the supercharger is producing.

 

Before and after test would be great. I think the M271 C230k runs 11 psi? I may be wrong.