I like the adjustable speed idea. That's why I'm looking at air flow and efficiency maps to find a good fit rather than just throwing something together. It's good to see someone on here who has done a merc swap. I'd like to see your build if you have a link to a thread. What tranny do you have in your jeep? Is that the AX 5 speed? I've heard as well that the sweet spot on the mercedes is up there in the higher revs. I'm not sure if that is dew more to the turbo or something else about the engineering in the motor. It seems to me that all motors will get better mileage if kept at a lower rpm as long as there is enough power to keep it from putting stress on the motor in the lower revs, but I'm no engineer. I guess that would be the definition of a sweat spot? It's hard to say how a supercharger will affect cruising speed and mileage. I want to test it all out before my brother gets it. I told him if he blew the engine that we could get another one just as cheap and he sounded a little to enthusiastic about that idea.

The death wobble potential scares me a little on this scout. I would prefer to keep the lift to a minimum, but with the tranny situation still up in the air I'm not sure how much clearance I'll need for the oil pan. I'm also still trying to decide whether to do coils or scout 2 leaf springs. welding on ford wedges sounds easier than turning the front pads. If anyone has any ideas I would be glad to hear them. There is still planning to be done so any advice or idea are noteworthy.

 

my build thread is" Build OM 617 benz in a jeep cherokee with AW4 ". I am running a AW-4 auto, and I don't have a turbo, But my engine was almost new. only 30000 miles. The car sat in a shed for over 15 years before I bought it. I got it up to about 50mph, all was good until I stepped on the brakes. This was not my first death wobble. I hope it will clear up with some bushings and a new steering damper.
I forget what the MB was turning at highway speeds, but it was not that much different than the jeeps. I want to say just under 2500rpm at 65 or so. I honestly just don't remember. I stripped the engine out of the last MB over 5 years ago, and it was longer than that since it was at highway speed.
Are you trying to optimize mpg's or power? Have you looked at superturbodiesel.com - tuning performance turbo diesel mercedes, W123, W116 and up. OM617, OM60X They have some good write ups on how to turn up the IP's

 

Thanks for the link. I'm trying to optimize both if that makes any sense. In order to do a proper supercharger test I need to stay within the superchargers efficiency area, so any fuel increase would have to go along with that or else I'd have to spin the Eaton into a less than optimum zone on the compressor map. Now one advantage of the gen 5 m45 is that even if it drops out of the most efficient spot it will still be more efficient than an m90 or m62. So what I will try to do is raise the boost level and fuel to a point where I'm optimizing both and not loosing one way or the other. An issue I'm trying to avoid is over fueling and causing high EGT's in the lower rpm's. So fuel adjustment will definitely come into play, I'll do some reading and see what I'm looking at. What do you get by way of max boost? I've heard stories of people getting as high as 15 and some as low as eight. I think that is in the 3500-4000 rpm range. I'll have to do some checking and see what mercedes lists as max boost from the factory. That will give me some idea of how much more fuel if any I would need with the Eaton. It just occurred to me, I would have to leave the ALDA active so that I'm not running to much fuel when the supercharger is bypassed. I don't quite understand how the ALDA works. If it controls fuel at varying boost levels than an increase in boost would cause an increase in fuel right? How does mechanically turning up the fuel go along with that? Maybe there is a limit to how high the ALDA can increase fuel...

Here is kind of an idea of why I decided to go with the m45. For some reason photo bucket isn't working right but you can still click on the link to view it. If I keep boost at close to stock levels than I'll be in the primary efficiency island in the middle of my rpm range. This may or may not allow me to turn up the fuel, I'll just have to fine tune it when it's ready and see what I net. If I maintain stock power levels than I'd say that's a success as far as the supercharger experiment goes.

http://s1299.photobucket.com/user/rembrant88/media/128356-1_zps65ec9cf9.gif.html

 

2200-2300 is about the lowest I've seen anyone be able to highway cruise with an OM617 as most folks shoot for 2600-2800. I don't know how your supercharger will affect the equation but as I understand the OM617 fuel pump it supplies a metered volume of fuel according to the rpm's. The alda only reduces fuel at low rpm's to avoid unburnt fuel. With a turbo, you would need to change from the 3.07 axles. Maybe the supercharger will change the equation though? I'm interested to see.

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This is the flaw in your design plan as there's no fuel screw like on the Cummins diesels. The only way to turn up the fuel on an OM617 IP is to replace the elements with larger. Right now the only known place to have that done is in Finland.

I just don't think there will be enough energy in the fuel provided at 1800 rpms to push the Scout 70 mph no matter how much air you pump into it. If you figure out how to get more than a nominal increase in fuel out of the OM617 IP, then you will be a God on the mercedes forums.

 

Okay, so if the ALDA only reduces fuel at the lower rpms than bypassing it would give me consistent fuel flow. That's what I want as long as it doesn't over fuel, which seems unlikely. To keep the supercharger efficient I would have to keep boost low anyway and bypassed some when cruising. I want to take apart the om617 pump and see what goes on in there. I have heard that fuel can be turned up by messing with some screws but it sounds potentially hairy. I think with the m45 and the mercedes intercooler I should be alright for cruising at that speed but you may be right. I think there are plenty of improvements to be made on these engines. Maybe someday there will be some easily attainable aftermarket fuel mods for these motors.

 

Walkenvol is wise in the ways of the MB diesel

 

ALDA restricts fuel based on turbo boost to avoid smoke until the turbo pressure builds. Again, I'm unfamiliar with the behaviors of a super charger so possibly it provides constant pressure and doesn't have "turbo lag". If so, then your ALDA would serve no purpose.

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Not sure where you heard that, but its inconsistent with all my research. Do some reading on superturbodiesel(dot)com and peachparts(dot)com as there's lots of info available on how to tune an OM617. I've not seen where anyone has been able to pump more fuel without larger plungers in the IP. This guy in Finland appears to be the man when it comes to modifying IP's . A few folks have shipped their IP's to him and were pleased with what they got back, but it appears to be in the $2,000 range with shipping 2 ways, european taxes, and currency exchange rates.

Some folks add some more energy to the equation via water/meth injection. Besides making sure the IP is properly timed motor and the rack limiter is properly adjusted, there just isn't any way to get more fuel from the stock IP.

 

Ouch. That pump upgrade is pricy. That's one cool land rover. I guess the advantage I will have is the low boost so I shouldn't need more fuel, if that indeed turns out to be a measurable advantage. The m45 will be pushing air at idle so sounds like ALDA removal is a sure thing. I probably misread when I was reading through the threads on the fuel system. I'm familiar with both sites and am sure to frequent them more as this project progresses. I'll go back and find what I was reading and maybe you can advise me further on those workings of the pump that they describe. It would be fun to take a closer look at the pumps and see what improvements can be made. That's probably not the area of machining I will get into, but I can't imagine myself not playing with that kind of thing once I have the experience and tools. Seems like there would be a market for mercedes diesel upgrades if they were less costly and readily available.

 

You could start a cottage industry if you figure that out.