vrus

Time to consolidate some information that I have been scattering around on a long term project I've been working on...

We all know the SLR style intercoolers are the holy grail for these cars... I'm giving it 1 more try at an alternative solution to see if there is a more cost effective way to achieve the same or similar results.

Step 1 requires the installation of a large front-mount heat exchanger which replaces the tiny stock one and has a frontal area almost as large as the radiator itself. When you split the 2 cooling circuits on the stock car, the main issue is volume of coolant that is left to tend to the intercooler... With this huge front mount, there is plenty of room for coolant! Here are 2 pics showing the install of the front-mount.




Step 2 will be to coat the front mount heat exchanger with the heat dispersement coating that I've mentioned before.. This increases cooling efficiency by 20%.

Step 3 will be to replace the stock S/C intercooler located below the S/C with a more efficient setup. The below pic shows a comparison of the stock S/C Intercooler with the new one that I had made.. Top is stock, bottom is new version..

Notice the new one has NO BYPASS VALVE! Eliminating the bypass valve allows for a gain of +2psi at the lower end of the RPM range. Not sure of the exact boost changes at the mid & upper ranges... The ECU uses the bypass valve for several functions; one of which is to bleed boost at low RPM.

Also notice the core size is larger.. The new one uses a much more efficient core than the stock Garrett one. Pic 2 & 3 below show the differences in the size of the mouth between stock & new one.. Notice that the new one is almost 0.5" bigger. My supercharger will be ported & the mouth enlarged to port match it to this new intercooler mouth.





Step 4 will be to verify my claims with some hard data.. I purchased an aviation grade dual input temperature gauge with stainless probes. 1 probe will be tapped into the mouth area of the S/C's intercooler BEFORE the core and the other probe will be tapped just after the core.

The great thing about this gauge is that it tells you Inlet Temp 1, Inlet Temp 2, and differential temp..

Here is a pic of the gauge & probes...

L8Apex

Sweet! What cores are you using? What ill effect if any will occur from the deletion of the bypass valve? Keep up the good work. I'm saving my $$$.

chiromikey

you know i've been waiting for this!!!

sgtstanko

Very Nice!

rflow306

For sure.

SteveFox

Can you make me some Kleemann headers, and tune my ECU next

vrus

I'll give more details about the buildup once I've done some preliminary testing.. Too early to let the cat out of the bag..

As for ill-effect.. The bypass valve is also used to help off-S/C driving.. the air bypasses the S/C and goes right to the intake manifold... With the NO-BYPASS valve version, air will be forced to run through the core so I assume the response wont be as smooth during off-S/C driving.. That might be why the mouth is 0.5" bigger; to allow more airflow to compensate...

All I know is that the late 2002 SL55 originally had no bypass valve and SLCharger on this forum has one of those and he doesnt complain about the drivability.

I'll give you a definitive answer as soon as I install it.

Mikey!!! You know one is yours whenever you want it. But let me test it first and make sure you guys dont waste your money.

Thanks Stephen! How are you liking your 80mm TB?

Well.. as a matter of fact... Ask Albert (rflow306) how his ECU is working.. 11.34 @ 123mph...

stevebez

Wow thats some serious kit you got going there ....

Victor I suggest you consider doing this kit in 2-3 stages ...

Stage 1 : New Heat Exchanger (& pump I assume)

Stage 2 : Add ported stock IC body - port matched to S/C unit (is this step worthwhile?)

Stage 3 : Add new I/C unit incl new core and bypass valve delete

Seems like stage 3 could add substantially to the cost - although it may well result is some substantial benefits though.

So in your testing any chances you could run with the new H/E on its own and then run with both units fitted? The comparo would be very usefull..... you would be able to comapre the relative efficiencies of the cores (IAT delta and the comparative boost drop off) - also will be able to distinguish which element of the kit provides most bang for the buck.

jparch

Vrus you talk about removing the by-pass valve and gaining more boost. Can you please explain what you gain from this?

See people don't seem to understand, adding more boost at low rpm and low vehicle speed causes many problems!!! You said the old SL55 didn't have one, do you understand why mercedes put one in?

See the problem is at low rpm with extra boost the car is under severe load, guess what it causes detontion! Mercedes realised this, thus the by-pass valve!

Also guess what happens with extra boost at low rpm and the car hooking? Broken parts, another reason why mercedes choose to limit low rpm boost! Why do you think even SLR 722's run a by-pass valve?

Ok so i guess your gonna tell me about the DTM's have the same set up! OK guess what? DTM's have stronger axles, driveshafts, tranny's, etc..... Also DTM's have different tuning that limits timing at low rpm so no detonation takes place! Vrus, how will you remedy the timing problem for everyone? What happens when stock 55 cars, or even tuned 55 cars start having low rpm detonation? Lots to think about huh?

OK you talk about extra boost! Well actually your not gaining any overall boost at all! All your gaining is low rpm boost, but the overall boost is still the same so nothing gained there!

Let me guess the bigger core is suppose to help! News flash! By adding a bigger core longer core in there, you are actually adding more restriction in the original flawed design! See the problem is the stock core need to be taller and wider, not longer, so Vrus you have only added to the problem! Even if the core flows better, it is still restricting more because the air now has to move through more cross section!

Moving on, with the bigger front mount Vrus, have you actually figured out what will happen in the summer time and the radiator is not getting enough air, and the air con is blasting? What are the long term effects? There is a reason why Evo and Renntech added there coolers down below so it does interfere with the cooling of the rad!

See there is a reason why guys, e.g. Bleek , will run an SLR style cooler, we figured out problems that will occur with using a stock design, and how much it will cost in the long run! We replaced the stock intercooler with a "straight-through" style manifold, but we still run a by-pass valve, as detonation and parts breakage is a very serious concern! So what will cost more in the long run vrus, broken drivetrain, and broken pistons, or a well designed SLR cooler that helps gain more boost and is more efficient? We have to take into account the hundreds of hours that teams of engineers spent coming up in designing the total package.....

Just wanted to note these things so none of us run into problems!

stevebez

Wow ... talk about spoiling the party .....

On the bypass - yes I am not too partial about that either - personally I think you will gain 75%-80% of the total pacakge with just the new isolated ciruit heat exchanger and bigger pump.

If I were to go to the trouble of fiddling with the IC I would probably look to do it as per Bleek.

But dont see why you shooting him down - he is still developing this kit so give him a break will 'ya!

jparch

not shooting anyone down , just stating facts the engineerings that designed this engine/car spent countless hours looking at every possibility, as do some of the "high-end" tuners.....

vrus

Detonation issues can be controlled by the tuning just like it is when you add a huge pulley on your car.

As for the big frontmount and other comments.. This is an exploratory project.. I am documenting the steps I am taking and already stated that I have to do the testing in the dead of summer in order to know for sure if this will work or not.

Finny has been running a big front mount for a while in Australia and I dont think he has run into any issues so far.

The conclusions will come at the end of the project.

rflow306

Sounds like a lot of speculation with -out any facts.

The slr coolers will still need a heat exchanger or they are worthless. So the problem about air flow across the front of the car in the summer holds true for all current designs. Victors core and a large reservoir in the trunk with ice will work better than any slr cooler core with just water.

As far how much better the slr coolers are that has yet to be seen. The only dyno posted is the Renntech one, which I'm sorry to say was not very impressive.

Please guys don't interpret this as an attack on renntech.

One last thing about parts breakage, any thing can break when you start to make power including top- knotch after market parts. Go racing for one season and you will quickly realize that.

jmf003

Looks awesome, Victor! Can't wait to read the results!

bleek

Actually rflow, the info jparch speaks of are actual facts! People seem like they do alot of research, but i am actually very close with a 20 year veteren tech at MB. MB had many problems with not having a by-pass valve, this is not about spoiling parties, i commend vrus on his efforts, but when things are not researched enough, problems will arise! Jparch was simple stating a fact, so that people prepare themselves to do other mods to there cars, and not just bolt something in, and hope for the best!

The SLR coolers do use a front heat exchanger, as my set-up uses the stock one, plus my extra lower front mount, with a dedicated system. I agree the Renntech one is lacking to say the least, as using incorrect cores, and understanding actual SLR design was a major flaw. This is why i based my SLR coolers on the exterior of a Renntech cooler, (because for some weird reason i like the look) but all the internals are changed.

Rflow your right about the parts breakage, but you have to remember, MB has to minimize parts breakage, as it would be a huge problem when there flagship converable was to have to constantly come back for warranty problems, how do you sell cars? It's one way to cut down on parts breakage, but still allow the car to make the same power. SLR still run by-pass valves for a reason.

Good job to vrus, as it sems like he's the only one willing to try to find new ways to step up, but we do have to becareful of why things are done. Maybe a bit more research bro, but keep plugging!

lbE55

Victor:

I want to thank you. I have learned so much from you about the issues impacting our cars. I really appreciate you documenting your thoughts and processes for the rest of us, and also your willingness to explain your thoughts and to respond to those of us that do not have the level of understanding that you (and others) have about these cars.

I have benefitted enormously by following all of your efforts. I always make it a point to read your posts. I am on the edge of picking up the 80mm throttle body kit, and seeing your projects makes me want one even more.

Thanks again, Mark.

JAYCL600

I which you had a 600 to play with up there, im sure there are some shortcoming of this motor that need to be further explored.

Grumpy666

IIRC, the valve uses a stepper motor for actuation, so there is probably sensor feedback for motor position provided to the ECU. I don't know if you've included this provision in your plan, so be aware.


I can't tell from the pics (were you in macro mode?), are the actual sensors isolated from the mounting hardware? You don't want the measurement of the air to be influenced by the temperature of the IC housing. Just a thought.

komp55

The factory used a dual IC radiator set-up in the S55 AMG (large radiator in front of the engine radiator smaller radiator where the E55 IC radiator is located), and I don't think I've read of any overheating issues with such a factory set-up. In fact, that will be my approach to modding the IC - get the S55 parts and substitute for the existing one. Evo and Renntech piggy-backed the lower one because it was easier to install and more profitable for them to sell a $300 radiator and a $250 pump and a few micellaneous hoses, clamps and mounting components for $3,000 or so. It's called good marketing, not necessarily good engineering.

mclarenm8d

+1 ... as a CL55 guy, I don't plan on rushing out and spending money on RennTech IC radiator upgrades. My CL55 is shockingly similar to an S55 in setup.

SSM AMG

Wait are you guys saying that the S55 cooloing setup is different to the E and CLS?

Yacht Master

VRUS

Very interesting, I like your radiator and I see that monster Johnson pump too. I would not worry about the engine overheating cause of a restricted air flow, (see insert) MB got away with it, you can even add a fan.



Your heat dispersement coating, can't wait to hear more about that.

I assume that you will be running the supercharger ALL the time. Correct me if I am wrong but can the motor run with the super charger off and the by pass closed? My understanding is that the S/C is almost positive displacement and could not pass much air at all. My S/C freewheels at idle, cause the bypass is open and the bearing friction/clutch pack is greater than any compression load. Is the 2 psi mention be leakage in the bypass butterfly? Your new I/C looks real good and still fits as would a stock I/C just great, I am sure it has more fins and tubes than the OEM Garrett. As good and valuable as OAT, IAT, TIT, TOT, are the temps in the coolant side, they play an important part too, a consideration might be adding 2 probes to the wet side. Just my .02 cents.

How do you find these parts? is the oversized S/C to I/C inlet horn a Mercedes part? the cooler looks the same as one on a Detroit Diesel 6V92TAIB and the Y pipe is MB to?

I am currently gathering I/C temperature data for my radiator and pump upgrade. I'll post my thermo loads and pump size and radiator size for a car that has moderate to severe duty in South Florida.

Great projects, Good luck to all, VRUS keep up the good work!

vrus

Thanks John! Hope to complete the prototype kit install on my car in the next few weeks.

Thanks!

Thanks Mark! Means alot. I just get ideas in my head and start chasing them down.. Sometimes they are not-so-great ideas, but half the fun is trying and learning from your mistakes.. Heck.. The only way I will learn more is to try more.. so I keep plugging away.

I can definitely say that in the 2yrs of ownership of this car I have learned alot about it; what works and what doesn't.

I have my eye on a SL65 that has been for sale a few times.. keeps getting relisted at a lower price.... I've been itching to buy it for a while now... I have been dreaming about a 1000hp, 1000ft/lb SL65 for a long time.. LOL..

What ruins it for me now was the latest Top Gear video where they tested the Brabus SL65 and said Brabus had to de-tune it because it was making 1000ft/lb of torque but was not driveable so they pulled it back to 800ft/lb... He gave it a horrible review... Ugghh..

vrus

Thanks!! I am looking at the circuit for the S/C Clutch right now.. I am trying to figure out a way to make a small circuit that allows me to bypass the ECU control of the clutch and have it permanently engaged when I want it.

I am not exactly sure how the car will behave with no bypass valve and the S/C disengaged.. I know that the early 2003 build SL55 had this configuration and the car worked, so its only a question of the overall driveability.. For me, I care more about how the car runs with S/C engaged so if off-S/C driveability suffers it doesnt bother me.

I am constantly looking through EPC, WIS and DAS for any info I can find.. Most of the things I come across are from other cars.. This base piece to make this new S/C intercooler comes from the CLK-DTM car but the core has been modified for better flow.

Yup.. There is.. Pin 5 & 6 of the harness are the output pins which return position of the potentiometers. I've got 2 solutions.. First one is to disable bypass valve in the ECU completely.. This ECU file that is in my car and is in Albert's car pretty much keeps the flap shut most of the time anyways, so I think my programmer can just disable it entirely.

Second alternative is I will get my engineer to make me a small circuit which will plug into the harness and act as a simulator for the bypass valve returning the info to the ECU.

Hmm.. good question.. I believe they are because there is a rubber o-ring sandwiched inbetween the end of the probe and the top of the wiring harness (its a screw-down type fitting at the top of the probe).. I'll take a better pic tonight. I was using my crappy camera for those quick pics.

jangy

I'd be interested.