Hello all, I am new to this forum, but have been ghosting a number of mercedes diesel forums over the last 2 years to gather information on improving engine performance.
This is really a shoutout to ForcedInduction, tho currently banned on most mbz forums, but your older posts have really done a wonder on my om617 and i can proudly say i know the top end of the thing really well.

Ok enough kissing a$$, here is the sitch:

I have a boost gauge, pyrometer, and still the stock t3.

-in a few posts Forced has claimed the w123 na manifold will fit his 617 setup, tho he opts to use the w115 long runner, but he does have a different turbo, Will the w123 intake manifold fit over the stock t3 if clocked correctly?

Others have said no on similar models, some have said it will, has anyone actually tested it over a stock t3, NOT KKK turbo?

I ordered one off of ebay, almost mint condition came in, only $60 free shipping and i will use it no matter the headache.

If it will not fit over the stock t3 ( it really looks like it might, but i need to drive the car to school till the weekend, so i cant comfortably swap) WHAT are my options, (modify exhaust manifold, replace/ modify turbo, etc)?

Money is no issue, I am searching for the SIMPLEST and MOST RELIABLE options.


Current setup, if it makes any difference:
-Real cold air intake, oversized k&n filter for GM v8s, ran from turbo to under bumper with 3 inch piping.
-Air to Air IC is mounted front (28"x8"), minimal bumper chopping, pipes are 2.25 aluminum with NO SILICON elbows, all bends are aluminum to reduce lag.
-EGR delete
-pyro/ boost gauge
-engine is sparkly clean, in tip top maintained state with ~300k miles, only trany is in question
-amg 8.0x17 rare monoblocks with no spacers
-replaced holy muffler with thrush glasspacks and cool exhaust tip (im in San Francisco so i cant run it too loud)
-remote locking system with new vac pump and wiring to avoid confusion with the pumps solenoids

 

uppon closer inspection, it looks as though the manifold will not clear the t3, perhaps a holset 25, 35, or 40 like the one in this video would be an easy swap and a rather inexpensive solution:

Mercedes 300D holseth hx40g - YouTube

or ebay 25
eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

 

Thanks for the quick response! I keep worrying that the thing wont fit, and the more i try to eybeball and ruler calculate the less it looks like it would, but man that would be an easy solution. Did you ever run a na w123 setup such as this that you could comment on performance wise?

A little water in the engine does good and cleans, and my filter is right beneath the headlight, but up against the bumper with its curvature, so im not worried about puddles, and dont drive the beast in rain very often (my car is also not lowered, and the rims push it up higher).
To tell you the truth, k & N is not my favorite, but fram has the worst reputation of filtration companies other than STP.
I shouldnt be arguing with an experienced pro like yourself tho, and may revert to running it behind the headlight again.

What fuel injectors do you use on your om617 btw Forced? its getting time to replace mine after all these miles.

 

the na w123 manifold is overlapping my t3 turbo by ~1/4 inch, what should i Do? what are my simple, most reliable options?

-modify exhaust manifold/ flange angle?
-turbo with different shape?
-anyone have a w115 long runner manifold they want to sell?

 

So i ordered a hx35 because the general consensus is that it will spool a little later than the garett t3, but get the job done, and will most likely be a noticible upgrade since im still running the original untouched 30 year old turbo. I will turn up the fuel pump to max, and eventually have the local diesel tuning shop upgrade my 5mm mw plungers (its a jump to an unnecessary 8mm, but i will run it a little starved at that point).

I noticed a youtube video with a mbz running a hx40 with na w123 manifold like mine, and it seemed to clear just fine, figured the hx35 will too.

I will start taking pictures once everything arrives and post my results, any ideas what im gonna do with the turbo oil supply line? i picked up an extra one at pray and pull, but it looks like im gonna have to tubing bend it or have a shop chop/flare and connect stainless hose.

Anyone done anything similar that they could comment on, any info will be greatly appreciated!

...and yes forced i will have the air filter on a right angle behind the headlight so it wont be a cold water intake.

 

My 82 300sd is a rocket right now from 0-20mph, and 60- 95mph. My problem is a massive lack of power between those ranges, I realize it is because of my bowden cable setting, but no matter how i set it i have to compromise power in one of those ranges. the hx 35 should be perfect under load in that range and thus a viable solution to the problem. Look at this bad boy

In car video w116 with Holset hx35 turbo - YouTube

 

he does have a video posted of his car drag racing and kicking a volvo/ vw's a$$.
83 300d with 7.5mm ip. Hx40turbo and race tranny - YouTube

Another thing, your nitpicking/ missing the point of my question, of course the tubo is going to spool later than the t3, but Realize i am paying return shipping if the thing doesnt clear the n/a long runner manifold, as this is essential to getting the turbo to spool up more quickly.

All i am looking for is a viable solution to getting that n/a manifold on the car and clearing whatever turbo will fit without compromising power.

THe more important question to answer as well is what am i going to do about the oil supply line? is the flare/stainless braid something that i can do at home or the local auto shop can do? I have a spare metal one from pray and pull, can i simply heat it up and bend it with a tubing bender? what is best from your experience?

 

lol I thought he tried both because half his youtube vids are hx, half hy. what a rube.

Im counting on it. My purposes are drifting, show, and outrunning Daly city fuzz back into my san francisco county. Im not running 0-60s, but 60s -xxx at 100% throttle. THese cars are too heavy for 0-60 with tiny engines, acceleration is a dead loss, im hoping the long runner intake will help.

He was using an hx40 which is definitely too big, an hx35 would do better with adequate fueling, correct?


Dont underestimate my appreciation for your posts, im naturally blunt, i was just honing you in on the topics i need answered most. Your past posts with the ~banned next to them have made my ride what it is today.


I get the preceding fitting references, but please elaborate on this part, im no mechanic like yourself.

I see now, (from that hx40 burnout video you were dissing as turbo617 about making his car slower) how he got it to clear the n/a manifold, he put a clamp on 4" exhaust coupling in the middle of the turbo to push the tall part forward. I have the option of doing this on the hx35 i ordered, any potential issues?

 

I read on yet another forum that he hydrolocked his engine with an even lower than mine cold water intake, in a suburban environment though, an extreme punishment for experimentation.

THats exactly the terminology i was looking for, it looks like in the vid below that he used a v-clamp 4" exhaust coupling added between the turbine and bearing housings. It might just work with propper support. cant see it till the last few seconds, and hard to make out his exact rig.

Mercedes 300D holseth hx40g - YouTube


Thanks for the oil line restrictor info, where would you recomend online to order the pieces i cant get at my hardware store?

Just to get a better idea of the housings scale, if an hx40 is 16-18, and the hx35 i ordered is for sure 12 on my paperwork, how big is my ai garrett t3's?

According to my tach and boost gauge, the garrett starts spooling around 1500- 1800 rpm, full boost at 10psi by about 2200-2500; are you saying the hx35 wont start, mid, or finish at 3000rpm?

Also im getting a barage of faster spooling tactics from the nissan forums, like building back pressure, wrapping the exhaust, etc. Any specific ones for diesel i should know about?

 

The new hx35 also wont clear the n/a manifold, do you have an old short runner to sell me forced, or any ideas on things i can do to make a turbo clear the w123 one? I contacted the guy with the modified short runner one Dieselboy740 with the hydrolocked engine, last i heard in january he still had it.

Thanks for the very informative thread on oil line fitting/ pressure reducers btw, will definately help as i start ordering. I also dont really have a wrapping fever, just looking for anything to make the holset spool just a little sooner.