FWIW I found it surprising how the '617 likes to spin. Expecting it to cruise around 2 grand but realizing in my coupe it's turning over 2,600 RPM @ 60 - close to what my '67 and '85 Chevy trucks spin with non OD transmissions + 3.73 and 4.10 gears respectively - and how strongly it takes off and runs up to 75+ (around 3,500 RPM) it's certainly not characteristic of most other diesels we Americans are used to.

I don't think a turbo will help much in starting from a stop up a hill. It only adds boost in proportion to exhaust flow-rate, which is mainly at higher rpm. The only way to get that is to either have a very low first gear or start by revving the engine in neutral and slipping the clutch, which will definitely wear out the clutch.

I have the exact opposite issue. Too much power and not enough gears.

My w123 617 powered 4 speed manual 300D had too much low end, 1st gear was nearly useless, it'd burn rubber and then wind out to a blistering 5mph nearly halfway into an intersection where then a rapid shift to 2nd was needed to gain any speed and not get t-boned.

I dropped in a 2.88 diff. could have likely went with a 2.47 and been fine in the hills of east tennessee, and I mean hills.

I also have rather small rear tires, I think they're 185/75s. will likely step up to slightly larger when they wear out, hard to beat free tires though.

its no racecar by any means, but it all depends on what you're used to. trying to compare my w123 to my 12 valve, its night and day, but the w123 is very comfortable to drive around twisty mountainous roads or on the highway with how its set up now.

I've got a K26 turbo and alda deleted, boost adjusted to peak at right around 10-11psi. the k26 spools noticibly faster than the garret it had stock, but bolted right up as they were used on some models.

How do you like the ALDA delete, and how is the smoke on it? Now that I've got my engine sorted, I'm looking at some other tricks.

Based on your suggestions, I think we're going to start with the 300D rear end and reseal the ALDA. I forgot to mention, we did rebuild the lift pump.

I had a 85 300sd for 8 years. It was lazy off the line until I timed it. I set the static timing at 12 degrees after top dead center. I also had a new timing chain with a 2.5 degree advance woodruff key so the cam was advanced just a tad and that makes the low end come in sooner. The guy that bought my car had owned 5 300d(s) and none ran like mine out of the hole.
So make sure the engine is timed somewhere between 15 to 12 degrees after top dead center (static) and see if that's enough. If not then try advancing the cam.
BTW I never messed with my alda. I also had a manual boost controller set to 15 psi.
Another discovery was the engine started much better and got up to temperature much faster after being re-timed.
Roddy

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Not true anymore. Everything I've heard and read over at STD says that a VNT turbo will basically spool right off of idle and virtually eliminate all turbo lag.

the turbo im running right now will be over 10psi by 1500 rpm. its not a vnt turbo its a Holset HE221w with the 6.5cm exhaust housing. admittedly im running a large pump which does speed spool a lot but even before i swapped in a super pump it was fully lit by 2000 rpm. that being said for a manual with no TC to allow slippage to help spool my best recommendation for bumping the off the line power would be to advance the pump timing as much as you can without it nailing and throw a 2.5* cam key to advance the cam timing slightly which makes an appreciable difference. if you are willing to go a little farther you can port match the head and manifolds and get a more free flowing exhaust. you wouldn't think the stock one is all that bad but i saw a dyno run with the stock and with just the down pipe off the turbo and the open pipe showed about 15-20 more lb/ft of torque.

Best thing I've ever done to any of my 617s.

I've done it to 2 of the 617s I've owned, and its like driving a different car.
I always took the alda off, flipped it over, removed the phillips screws, and then removed the lower diaphragm part, reassembled and put back on and either plugged the tube coming from the intake or used it as a tap for a boost gauge.

Smoke is barely noticeable in the rear view unless you really shift early and hold it WOT, and even then you get a slight haze, then boost comes on and it cleans up. pulling a 26ft pontoon trailer I was told by a friend following me that it smoked quite a bit. but I was working it pretty hard to get that around these hills.

It makes throttle input linear. no surge of power when boost hits. just gradual power increase as rpm (and thus boost) climbs.

There are naysayers here that will swear up and down that a properly adjusted and functional alda is superior. I've owned 3 617s personally, and driven about 8 others, all in various states of good/bad/dying. best one I've ever driven is the blue auto I've got. it is like new inside and out other than a little clearcoat wear around the fuel filler that looks like a buffer was a little too vigorous.

I drove the car when my dad first got it, before the turbo drain went and he wiped the cam out and subsequently gave me the car and I put a new cam in, so now in my mind it isn't a "pristine" engine anymore, but before that it was the tightest, smoothest 617 I've ever driven. except that like every other one leaving a stop sign or light you put your foot to the floor and it goes bluuuuughhhhhhhhh and creeps away until around 1500rpm and then takes off like a bat out of.... well you get the point.

My grey car is the total opposite, it was abused bad. its worn out in a lot of ways. starts harder, idles rougher, everything about that poor car says it shouldn't last (but I'm making it). but with the alda gone, its a rocket compared to the blue car, even when it was still automatic. you'd get a little haze if you went WOT from a light, but it built boost faster and by the time you were through the intersection there was no haze.

To reiterate: Best mod ever. Feels like driving a car instead of a really tiny school bus.

I am not experienced with it but it seems like the variable vane turbo might help.

It will but the main issue is controlling it.

Head over to STD. Before "Forced Induction" became a total tool and was banned over there he devised and posted a completely mechanical control system that was pressure based and didn't look very difficult to recreate.

his system is not bad but it only works in 2-3 distinct stages and you need to use the 2/3 valve cam to actuate it which not all cars have. i built a modified version of his/synchroG's design. i did some limited testing before deciding to go away from vnt's and its a much better system. it linearly modulated the boost set point based on throttle input and can easily accommodate a cruse boost reduction circuit and some more goodies. https://www.youtube.com/watch?v=PPlKrzaAQfc Syncro's mechanical VNT project

That looks fairly simple. Does he offer a kit?