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  #61  
Old 10-31-2004, 04:38 PM
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Quote:
Originally Posted by leathermang
Figure if the air temp blowing across the intercooler starts at the same temperature as the air going into the intake how much air volume will be required to cool it to
Figure how much fan power will be needed to make that much air flow across the intercooler fins...
I dont know for sure on this one, but was using the theory that more air across a intercooler would lead to decreased internal temps. As rpm drops near the gear change, but the car is moving faster, you might be able to reach a point where enough air is passing the over/thru the intercooler to reach a point where it cools below the ambient temp. I am in a bit over my head on this one- I am not a intercooler/forced air induction engineer. I can tell you how a sailboat can sail faster than the wind however.....


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  #62  
Old 10-31-2004, 05:16 PM
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I know just enough to keep Brian and a couple of other guys stirred up ! LOL
MY impression is that as an example ... if you have air at temperature ' A' and ' B' is half way.... then you need the same amount of air 'C' ( plus whatever is needed to make up for the less than perfect heat transfer of the type metal in the tubes ) passing across the cooling part....
Which in itself can be a lot of air... meaning a drain electrically to run the fan....
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  #63  
Old 10-31-2004, 05:22 PM
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Instead of putting an intercooler inline with the radiator and fan, is there room for a top mounted intercooler with, dare I say it, a hood scoop to provide cooling air flow? You wouldn't need extra fan power, and sometimes it can be easier to fit an intercooler above or to the side of the engine. Then you can use a hood scoop, WRX style, or run a ram air hose up from under the car or something. I know hood scoops are awfully 'ricer', but I have no qualms with them as long as they are functional and not those fiberglass deals w/ double stick tape.

Just tossing the idea out there.

peace,
sam
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  #64  
Old 10-31-2004, 05:25 PM
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Oh , Yes, Hood Scoops...
Why don't you start a new thread asking people's opinion of hood scoops....
You might be the first guy to be voted off the forum..... LOLOLOLOL
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  #65  
Old 10-31-2004, 06:03 PM
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Quote:
Originally Posted by leathermang
Oh , Yes, Hood Scoops...
Why don't you start a new thread asking people's opinion of hood scoops....
You might be the first guy to be voted off the forum..... LOLOLOLOL
ROTFLMAO........................

Good lord I needed a laugh like that after trying to deal with my fuel flow problem......................
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  #66  
Old 10-31-2004, 07:24 PM
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With all the added volume of air between the turbo and intake an intercooler setup would provide, wouldn't it also increase lag and move the power point?

Last edited by phantoms; 10-31-2004 at 07:39 PM.
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  #67  
Old 10-31-2004, 07:39 PM
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Hey, hey, no need to get touchy. Boy this really is an old-folks board.

I was just trying to be practical. People were concerned about fan speeds needed to maintain airflow, so I suggested a practical alternative. If you don't like the idea, thats fine, I was just tossing it out. Even the McLaren SLR has intakes on the sides and hood (though the intercooler is cooled by that hood-star cum intake thingy, which is pretty sweet.

However, if you want to totally smoke those kids in their rice cars, you really need these scoops: http://www.customautotrim.com/hood_scoops/ You don't even need to use screws to install them! OMG ThEY T0TALLY R0XoR!!

peace,
sam
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  #68  
Old 10-31-2004, 08:13 PM
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Quote:
Originally Posted by BoostnBenz
I have my doubts that our tranny can handle the 150hp/250ft-lbs previously mentioned.
Well, it is the same tranny that married up with the V-8 M116 in the 380SL/SEL's. Even in their emissions controlled choked form in mid 80s they were good for more than the aforementioned power levels. Now, as for the rest of it... all very interesting, and I'd be willing to consider the mods, but to my knowledge no one has successfully done it...making me think it can't be done in a halfway cost effective way.
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  #69  
Old 10-31-2004, 08:36 PM
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Wow, the post that won't die. Allow me to make a comparison. I know a little about GM 6.5liter turbodiesels. Like the MB 617 they are all cast iron, have a 21/1 compression ratio, are indirectly injected and non-intercooled in stock form. Stock 6.5's boost is set at 7psi. This is pretty low. The aftermarket and "tinkerers" have established that 12psi is pretty much the max boost recommended without an intercooler. This has been proven as the electronic 6.5's have IAT (inlet air temp) sensors that can be monitored while in service with a laptop and the correct software. It seems that anything more than 12psi and the IAT's increase sharply negating any benefit and causing the EGT's to quickly get out of line too. Since MB safety devices shut down fuel at 1.1bar or @14psi I suggest that the MB engineers knew of the sharp increases in IAT/EGT and choose to set the safety limits where they are. There are aftermarket intercooler kits for the GM 6.5's and the benefits have been documented with the laptop programs. On a stock 6.5 the IAT's can exceed 300*F when loaded and pulling. They can easily exceed 350*F on a modified 6.5 with more fuel and boost. Installing an intercooler on either stock or modified can reduce the IAT to within +30*to 40*F of ambient temps. The most popular is made by Spearco and fits between the framerails so I would guess it to be approx. 24"x8"x3" and it seems to cool a 6.5liters intake charge air just fine. The main benefit on a stock engine is reduced EGT's and heat load on the cooling system. The benefit on a modified engine is it allows the operator to stay on the accelerator when pulling a long hill, stay in a higher gear, etc. where before they would have had to back off the fuel due to high EGT's. It seems the intercooler doesn't neccessarily "make more power" it allows the engine to sustain maximum power for longer periods of time without damage thusly making more use of its power output. Regarding the ability of the MB transmission to withstand a power increase I would think 25 or even 50 more HP wouldn't really affect it in normal use. Normal use being the quick sprint 0-60mph, etc. and then just cruising around. Since with regular maintenence MB trans seem to last almost as well as the engines they would appear fairly robust. For a truly max effort hotrod MB engine an experience transmission rebuilder would know how to increase the line pressure to increase the clamping pressure on the clutch packs to keep them from slipping and get the power to the ground. There are custom injector builders around. I doubt they have ever worked on MB injectors but since they have modded just about every other type of diesel injector for the pulling/marine/hotrod crowd I am willing to bet they could do a set of high pop/high volume MB injectors if you were willing to pay. Regarding fitting an intercooler into a 123/126 chassis I think it would be fairly simple. The easiest way would be to do away with the AC condensor and mount it there. Another would be to convert to an electric fan and move the radiator/condensor back towards the engine to make room. Sure, custom mounts and fabrication but within the realm of possibility. I still don't think there is much of a market for a 617 intercooler. There really isn't a reason and no one seems to want to spend the money. Interesting topic though. I wish Ridge had followed through with the before/after tests to see if his intercooler worked or not. RT
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  #70  
Old 10-31-2004, 08:55 PM
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If someone could actually prove it accomplishes something I'd be willing to build up a intercooled system but I'd rather build my own system than buy it.

Spearco makes very nice intercoolers but their prices are a little out of hand in this situation, I'd either use a Starion or DSM intercooler in this case. I'd probably go with DSM intercooler as I have access to cheap ones and they are a very efficient intercooler.

Injectors can be extrude honed if the money is right, but before I'd consider sinking much into this car I'd probably get something else much more modifiable (Dodge Ram w/Cummins? ).

All I can figure is Subaru's marketing team must have forced their engineers to have a top mount intercooler. It just doesn't make sense why someone would do that, heat rises and they put it right above the motor. One of the first mods for a WRX is to rid of the top mount intercooler.

The current tranny may put the power down but will they last? The 603 will put put out a good deal more power than the 617 but most of their tranny's seem to fail every 100-200k miles as well.

Yes the intercooler would create a little extra turbo lag as it is that much more volume it'd have to pressurize before it could reach the engine. I'd be much more concerned with the effect that driving in the winter with a intercooler than this issue though.
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  #71  
Old 10-31-2004, 09:35 PM
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the key to minimising turbo lag is keeping the path as short as possible. Hell these things are no speed demon and I doubt a litle turbo lag would even be noticed. Reducing charge temps is a good thing. would even let you tweek a bit more fuel through it safely. However those of us with a W116 chassis are at an even greater disadvantage as we have a battery up front behind the RF headlight. Without going to a electric fan to allow spacing the rad back to allow a intercooler between the A/C condensor and radiator I can't figure how to make one fit. I won't give up A/C for it. And I have looked, and looked, and still haven't figured out a way to make it work any other way.
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  #72  
Old 10-31-2004, 10:50 PM
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Not sure if anyone's mentioned it before, but an air to water intercooler is also an option for tight installations. Some of these units are fairly compact, which allows for shorter lengths of turbo plumbing. The heat exchanger can be mounted somewhat remotely, but this typically requires an electric cooling fan, so the increased power and efficiency isn't exactly "free".

Also for the more adventurous race-types, these ATW intercoolers can be loaded with icewater that under certain conditions, can introduce charge air that's actually below ambient temps.
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  #73  
Old 10-31-2004, 11:16 PM
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Quote:
Originally Posted by BoostnBenz
If someone could actually prove it accomplishes something I'd be willing to build up a intercooled system but I'd rather build my own system than buy it.
I don't believe that there is any doubt that it will accomplish exactly what you intend: More horsepower at the same durability level. The question is not "whether" but "how much". You may go through this rather lengthy and costly exercise, gain 25 hp, and find yourself at the same exhaust temperatures as stock. Is it worth spending well over $1K developing a system that will provide 150 hp? And, there is no guarantee that you will be successful due to the potential need for larger injectors. The IP may not have the capability to provide sufficient fuel without a bit of rather costly rework.
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  #74  
Old 10-31-2004, 11:16 PM
123c
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Quote:
Originally Posted by phidauex
Instead of putting an intercooler inline with the radiator and fan, is there room for a top mounted intercooler with, dare I say it, a hood scoop to provide cooling air flow? You wouldn't need extra fan power, and sometimes it can be easier to fit an intercooler above or to the side of the engine. Then you can use a hood scoop, WRX style, or run a ram air hose up from under the car or something. I know hood scoops are awfully 'ricer', but I have no qualms with them as long as they are functional and not those fiberglass deals w/ double stick tape.

Just tossing the idea out there.

peace,
sam
I don't really think that an engine mounted intercooler would really work that great on an old MB diesel, mostly because there wouldn't be enough room... On a side note, what makes them work so well on a Subaru is that they are an H4 engine, and the engine sits much lower in the engine compartment, leaving enough room to mount an intercooler, plus the way that the intake is set up is a plus for this style of intercooler... Subaru has been using this style of intercooler since the late 1980s, which has been proven very reliable. On many JDM models, and some Australian models, they have a liquid cooled intercooler, which help some of the older Libery RS's produce near 300hp
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  #75  
Old 10-31-2004, 11:22 PM
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Well I guess since this is somewhat applicable here, Brian has said many times that he wanted to get a better exhaust system for his car. I heard from several people here that the difference between no exhaust and the stock is very small. Well the other day I ran into a guy who owns a shop that services MBs in alabama, he is Bosch certified. He was telling me how he could tune the 617 so it'd put rubber down in two gears, he mentioned that changing the exhaust will actually make a noticeable difference in power.

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