Modifying the OM617 300SD - PeachParts Mercedes-Benz Forum

forcefed44 · #1 05-28-2012, 04:40 PM

First off: I know this topic has been beat to death over the years and I have read up alot of the tech specs but here are my .02s.

My '84 300SD is up for a turbo replacement (seriously excessive play) and at this time I will do the intake manifold install for intercooler modification as well as a Garrett T3 hybrid turbo with Spec adjustable 18psi Internal WG. (Currently she's running an Alda deleted stock injector pump, CAI, side exhaust).. I have an "M" pump from a parted 300D euro car.

My Question is: Will this add any type of HP/fueling gains left alone (stock "M" pump? Is it worth the effort? I know the stock injector pump has a rack limiter which needs to be removed (so I'm told) to get more fueling and gains but I have heard and read of bad situations with adjusting the internals). I have been told with the M pump, it doesn't have a rack limiter, and I have heard of element replacement to 7.5mm??; but there is no one who will modify these things in the Tri state (NY,NJ,CT) that I have found and I'm not willing to send it overseas.. What about Bosio 265 nozzles? +/-? I just don't want to stick the new turbo and not gain a thing..

I know the OM617 is limited to power modifications without some serious dosh. I'm not expecting 300hp but since she needs repairs already. I would like to modifiy it accoringly.

Post of PM me..

Anyone's information could greatly help me here.

47dodge · #2 05-28-2012, 06:19 PM

removing the rack limiter is not needed, nor the greatest idea. It really is not the limit to what the pump will do, but the element size is the limiting factor. However the ip can be adjusted for a reasonable amount say 15%- 20% more hp, as long as you have air to support it. For most people this is plenty of gain, but for hard core then no, and larger elements are needed. And of course a bunch of other things then.

If you do not do any adjustments to the ip then all you mods will be sort of worthless.

Chesapeake VA? like near Norfolk? I am close to Fredericksburg VA

forcefed44 · #3 05-28-2012, 09:19 PM

Quote:

Originally Posted by 47dodge

removing the rack limiter is not needed, nor the greatest idea. It really is not the limit to what the pump will do, but the element size is the limiting factor. However the ip can be adjusted for a reasonable amount say 15%- 20% more hp, as long as you have air to support it. For most people this is plenty of gain, but for hard core then no, and larger elements are needed. And of course a bunch of other things then.

If you do not do any adjustments to the ip then all you mods will be sort of worthless.

Chesapeake VA? like near Norfolk? I am close to Fredericksburg VA

What would the easiest mods to the IP be with it being in the car? I only want to remove it to install the euro M pump and with that I am going to have a shop do it. I have heard of run-away engines and rough idling, etc.. I just don't want it to be weak on the bottom end.. South Cape Charles actually..

Chris

47dodge · #4 05-29-2012, 06:05 PM

Adjusting the rack limiter, but not removing it will give a nice gain without causing any real trouble. Any other adjustments need to be balanced with careful idle adjustments. You will be leaving a good bit on the table so to speak, but at least this is relatively safe to do.

Do put an egt gauge on.

you would be about 4 hours from me.

forcefed44 · #5 05-30-2012, 09:21 AM

In the information of removing the Rack limiter, The procedure is quite simple but my thing is performing the adjustments to get the car to run close to stock at idle and driveability.. I am not keep on the diesel IP setup once it's removed and there is no one who can do it locally (set up and tune)..

Chris