Would you pm me that info? I was going to install a manual boost control to increase the boost by 2-3Lbs. Boosting around 9Lbs now. I'd like to take it closer to 12Lbs. I understand that this is still in factory spec.

Sent from my SM-G530W using Tapatalk

I'm running 21-22 PSI with an almost stock turbo w/clipped impeller. It does run the EGT up pretty high by the end of the mile but I'll wager you could run - say - 15 PSI with no issue. The problem, of course, is getting enough fuel to use the air you're pumping in. I'm going to my big turbo as I'm now at the other end of the spectrum - more fuel from the SuperPump than I have air. It's sort of a balancing act.

I need to mount my GoPro so I can read the gages after a run. I try to monitor them but at the finish line it's MUCH more important that I watch the track!

Dan

I guess at one time I thought we would have to get eventually get into how to enhance the injection pump element loading. This on the stock injection pump cars..


A person will need a 0-60 pound liquid filled gauge and a meter that reads milli volts to get started. If harbor freight outlets do not have then there is one at slightly less than 15.00 delivered from Ebay that would do fine.


Add a piece of clear plastic fuel line to go in the return to make absolutely certain there is no air present. An in line on off valve .So that gauge does not see constant exposure to the vicious pulses the injection pump generates that destroys the gauge. Again a few dollar item including shipping on ebay from China. Plus enough parts and pieces to enable the gauge to read the fuel pressure anywhere after the secondary fuel filter and before the relief valve. Best to plumb this in permantly.


I will make the application multi post leaving out information to simplify. No short cuts should be attempted. In general I consider it safe if directions are followed to the letter.

#I get the gauge installed and close off the return line. Read the deadhead pressure the lift pump is producing. You may have to rebuild the lift pump or check that the tank filter is not obstructed. Yet average pressure a good lift pump should produce is not known. I have heard 35-50 pounds might be there but just do not know.


The 616 engines and the 617 non turbos use a weaker pressure regulating spring from the factory. A spring from a turbo cars pump should be installed on those engines. It is just under the large nut on the lift pump.


# 2 .open the return again. Read and record the milli volts present and record them. What the reading are in comparison to each other can mean many things. What I am interested in is the comparison to whatever you read with what is present now. To after the modification is complete. Any existing glow plugs in the engine unless burnt out should do.


You have to watch for any power balance shifting. I do not think there will be one. You have the gauge installed so we also want to know what the base fuel pressure was as we start. If it is too far below standard we will have to elevate it to the teens and do another milli volt check. Of course record all the checks.

Really cool installation, and certainly not your first rodeo. Glad you fixed the "won't restart hot" problem.

An easy way to get more power is to fool with the ALDA valve on top of the IP, but read the posts first. Many here have even removed theirs. Another way is to bugger w/ the boost feedback hose to the bypass (blow-off) valve. There are after-market kits that sit in that hose to fake the feedback signal for higher boost. Used by gas turbo tuner guys, I haven't read of anyone trying in our diesels. The ultimate is to send an IP to be goosed-up for higher flow by some Finns (or Swedes). Watch the you-tubes of M-B's spinning tires and pouring out black smoke like a tractor-pull contest.

Not for me, since I don't want to risk melting pistons. M-B turbo-diesels have oil squirters under the pistons, which implies they might already be close to the limit. I haven't read of many turbo-diesels reaching the mythical million miles of earlier engines. My 1985 engine failed at 330K w/ chunks missing from 3 pistons. I read of an older Toyota gas engine (4 cyl?) that reached such mythic status and might have been your original.

__________________
1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

It gets easier now. If your relief valve is not serviceable get one that is. Or a manual adjusting one. Shim the internal spring until you get a base pressure of thirty pounds. The importance of having lots of reserve pressure after this is that it keeps the cigar hose working and the relief valve open. As your fuel draw increases the natural obstruction of the filter is also overcome to maintain the thirty pounds base pressure. Now read the milli volts present and post them. You are only interested not in any individual voltage reading. But that there is no difference or change in value separation between them. This is a solid indication the power balance has not shifted and you are good to go.


The old 616 engines with this modification are substantially improved. . I see no reason the same change should not occur with the 617 naturally aspired and the turbo model. Any and all shortcuts to arrive at the elevated base fuel pressure are not wise to say the least.


Best of all is you have a permanently installed gauge with the valve to disable it from the system if you want. Never leave that gauge in a constant on situation. It will fatigue and leak fuel out. A very useful item to retain. I think that a clear piece of fuel hose in the return line is a requirement to make certain the system is not processing any air at all ever before you start.


I also suspect that a few members have pushed the base fuel pressure higher than stock but not mentioned it on site. If it is a gauged increase then I think it is safe for them to come out of the closet if they wish. We want to know what their impressions where. Also use any increased power intelligently.


For some technical reasons there is no sense to get into now. It is a power gain without any more smoke out the tailpipe basically. Or a good part of the gain does not involve it.