GT2256V VNT Turbo on an OM617

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Videos: (It sounds much better in person than on my cheapo camera.)
Quick tour around the car. http://www.youtube.com/watch?v=L-qW-PpPYy0

Some easy driving. Barely 1/3 throttle application. http://www.youtube.com/watch?v=cxAxmbDKzNY

Full output.
http://www.youtube.com/watch?v=3RhAKbmClIA

Just playing around with it a bit. http://www.youtube.com/watch?v=19BjRqvnAi0

Notes-

I cut a bead on the stock intake manifold to keep the tube in place.
The turbo works great as a warmup exhaust restriction (I can see this becoming a problem in the summer).
There is about 2psi of exhaust pressure and just a *hair* off the peg of boost at idle.
There is almost no boost drop between shifts.
EGT's still run in the same ranges. I can easily pass 1250*f.
Decelerating from highway speeds maintains about 6 psi of boost all the way down to 30mph in 4th gear.
The turbo seems hover in the 10psi boost and 10psi exhaust pressure most of the time I'm moving under load.
Boost stays around 8psi : 10psi cruising the highway between 55-75mph.
Max boost is about 11psi below 3500rpm and peaks at 14psi by 4500rpm.
Exhaust pressure at 14psi boost is 20psi. 5psi less than the KKK K26 turbo.
Exhaust pressure can pass 30psi on a hard takeoff and free (no-load) revving.

I will concede that the GT22V is too small for an OM617. EGT's are still excessive at full load.

My main concern is the high initial exhaust pressures (Pegs my 30psi exhaust gauge). I'm worried that it can float the exhaust valves. Does anyone know at what psi the OM617 exhaust valves will lift off their seats?

[rodion]

Hi Ratman,

your mod is very interesting.

How do you trigger the VNT system of the Turbocharger?
What else did you modify, maybe injection pump?
How much hp do you have?

Best regards
Rodion

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How do you trigger the VNT system of the Turbocharger?
What else did you modify, maybe injection pump?
How much hp do you have?

The vane system is controlled like a normal wastegate. Pressure actuator linked to boost pressure to automatically limit boost. Only downside to this is that it's always adjusting for max boost pressure in any situation. I'm working on a vacuum system and actuator to counter it and give me some more tuning control.

The injection pump is at all the stock settings internally. On the outside, I have just removed the ALDA to eliminate the "rush" of extra power as boost builds. My last dyno session showed 100.2hp at the wheels with the water/methanol injection. I imagine that a little more power is available due to the more efficient turbo design and larger exhaust.

[Heckflosse]

If you worry about your exhaust valves, you should try to get the stock valves from the turbocharged OM617, which are natrium-cooled.
I'm sure they will not be cheap but worth it!

[Haisuli]

Bigger turbo should also lower the EGT, your stock exhaust manifold might be also a limiting factor. Is your engine originally n/a or real tbo?
Om 617 should run great on a gt25 or gt30.

[Haisuli]

I translated the w123 and w124 diesel pump adjustment picture text, so it is easier to adjust the pump feed. Heres the pic:

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The engine is an OM617.952 so it started as a turbocharged unit.

Everything is working great so far. No regrets about the turbo.

I'm working on an electric valve that will route the actuator air through a manual ball-and-spring boost controller. It will be operated by a WOT switch on the valve cover linkage to instantly get the boost to 15psi (Instead of an instant 9psi and then slowly building to 15psi). This will allow the actuator to limit boost pressures the rest of the time for better economy by reducing exhaust backpressure.

I'm always watching for a GT2559V in my price range.

[Haisuli]

Allright then. I also have podered about the wot switch for vnt turbo, it might work well and it should be quite easy to align. Is your diesel pump stock turbo pump? I have read that it is quite tricky to adjust compared to N/A pump. You might get an increase on boost by adjusting the low rpm diesel feed. Also i thing that it is possible to adjust the turbo so that the vnt flaps are open all the time, cause the engine has a great low end torq and it gets boost pressures with the bigger normal turbo also. You might get an decrease of EGT:s. But i thing that you have tried that already. With bigger feed diesel engines gets the (low rpm) turbo boost faster.

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Now that YouTube has FINALLY got my video active, here it is: http://www.youtube.com/watch?v=uLgEnnQaR54 I do a bit of revving to get the turbo going and I get to 60 at the top of 3rd gear.

Nothing amazing, it's only about 1/2 second better overall. The video I have is 13.6 seconds 0-60 and the best I can get is 13.2seconds. The roads are still cold/wet so I kept spinning the right rear tire every time I tried to do a serious balls-to-the-wall run.

Bandimere Speedway will not be dong it's CSP (Open/Test-N-Tune) races until starting after May-02-2007 (LINK). Sometime after that I'll see about getting an official 1/4mile time slip.

[Haisuli]

Quite nice launch and sounds too.
Sometimes when its very slippery/icy i use 2. gear instead of 1. on my 300D n/a. It launches much better 0-40Mph with 2. gear. I have a 200D differential which is 3.92. My car gets to 60Mph with 3. gear slowly, faster with 4. gear. Older diesel pump limits the feed quite early. Im sure that when i change the newer pump i get 0-60Mph in about 18 sec in third.

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With a 3.92 I bet your 2nd gear take-offs are much better than mine. The USA did not have any MB's with the 3.92. The lowest gearing we got was 3.69 in the 240D (Which I have).

18 sec? Yours non-turbo?

[Haisuli]

Yes mine is non turbo.
I am planning to install newer feed pump, that older model one is no good. It is possible that i install an turbo in my n/a Om617, but i have to get the newer feed pump first. Newer know..

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The nonturbo engines are not built to handle a turbo. The stock turbo engines have many different internal changes for strength and additional cooling.

[Haisuli]

Thats true, but i know a few n/a Om617 with turbo. The n/a version doesnt like high boost, but it can be mildly turbocharged. The valves are different and the pistons have a oil cooling in turbo version. No problems with unmodified dieselfeedpump, ie bigger elements in the dieselpump-->more boost, more feed-->temp problems.

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I'd bet if you keep it under .35bar/5psi boost, use a pyrometer, keep a *close* eye on exhaust temperatures, and don't get greedy with the fuel, the engines lifespan won't be too significantly reduced.

[Haisuli]

I have heard that if the turbo is quite big, the exhaust gases and pressures arent the problem, if there is too small turbo, it gets the exhaust pressures up and starts to get heat into the cylinderhead. If the turbo system flows good, temperatures and exhaust pressures arent the problem even with 0,9 bar boost, which you get with the unmodified pump adjusted to the max.

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I'm getting a long hissing sound from the turbo when I change gears and for a few seconds after a shift.

I'm a bit confused as to if it's surge or not. It's a whoosh like a blow-off valve, not the stereotypical scissor sounding surge.

Here is a video of my engine. When I let off the accelerator, the woosh can be heard. http://www.youtube.com/watch?v=zTVZlK1OxvY

Could it be caused by the tubes expanding and retracting?

[Haisuli]

Sounds like a leak for me, it can also be those tubes you wrote. Some turbo specialist might know better. I linked the vid to the turbo forum, somebody might know.

[SamsonW123]

be heard. http://www.youtube.com/watch?v=zTVZlK1OxvY

Could it be caused by the tubes expanding and retracting?[/quote]

So anything new #4 Did get your tubing to stay on ?

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The tube was no problem, I had forgotten to tighten the clamp in that video.

I haven't solved the sound problem yet.