Mitsubishi KE75 turbo retrofit how to/not to

[Bigkrank]

Use a mitsubishi TD02 twin scroll.

 

[Ilikeurtractor]

Got the smaller turbo today but looks like bad news. There is a cicumferential crack around the compressor inlet. Not sure how deep it goes, but I'm thinking it may allow leakage from the volute back to the inducer which doesn't help me get to where I want to be along with who knows what other problems it could cause. This will push the project out at least another week. I hope the seller doesn't shrug it off as "normal" otherwise we'll have a problem moving forward.

 

[Ilikeurtractor]

Here is the reply from the seller:

The compressor housing is a 2 pc design that "crack" is the seam of the two pieces. It is pressed together inside and has a good seal. There will be no problem.

Guess I'll find out...

 

[upsetray]

If you would keep us posted of your results ,I for one would appreciate it. Thank You

 

[Ilikeurtractor]

I should have some results late tomorrow. I had to go do some other things that caused me to pull off of this project. I have the exhaust side connected and the flanges ready for the intake. Now I'll need to find a hose at Napa that will connect up to the compressor discharge and the intake port on the head. Ideally I'd go hard pipe all the way but for now this is quicker and easier especially not knowing the outcome. I lost some time also working on the oil supply. This turbo uses a M8x1.25 threaded inlet for the oil supply and finding something that will work as an oil fitting on short notice isn't easy. I ended up getting a female 1/8" NPT to flare adapter fitting and machining off the flare threads and putting a M8x1.25 thread on its side. Now I can at least put a 1/8" NPT hose barb adapter on it and get some oil to it with a hose for now. If you search for VZ21 turbo you can find places that sell the correct adapter, and I would certainly get one coming once I know this works if I ever had to do it again.

 

[Ilikeurtractor]

Here are some pics and a link to a video of the first tests. I guess the results are mixed - yes, it will build 5 psig boost at full rack under load so I suppose I accomplished what I was looking to do. I was hoping to do this more in the 2000-2500 rpm range but I'll take what I can get. Bottom line, in my opinion, is the turbo still appears to be too big and/or the turbine wheels are incorrect not that I expected it to be perfect, especially with this "trial-and-error" method I chose. I'm going to leave it on but I still have a lot to do before it's finished:

1.) The intake hose is resting on the exhaust manifold so I'll need to hard pipe it over or reroute the hose, or a different one. This will eventually require making a cut-out in the hood so it will close properly.
2.) Definately need something more robust for the oil supply and returns
3.) Need to install the intake filter and exhaust pipe (first task)
4.) Mount the boost gauge
5.) Paint up the piping
6.) Other things I can't think of right now (oh yeah, a turbo sticker in the end )

For clarification, the video shows the tractor in 6th gear with the brake on and me letting out the clutch to put the engine under load to build boost.

VZ21 KE75 first run - YouTube

 

[upsetray]

Do you think the objective of less smoke under load will be accomplished or do you think you need more boost ? Where are you that the elevation is a consideration? I live on the NY/VT border and the only smoke that seems objectionable is in the staring cycle ,starting in the in home garage brought many complaints from soot getting inside home living quarters. I do know the smoke at start will not change .

 

[Ilikeurtractor]

At times there should be less smoke. Not always though. Under acceleration or startup like you said there will be smoke just like with almost any turbo-diesel (or non-turbo for that matter) that is not fuel-restricted during low boost. One time I pulled a pretty loaded trailer up my street and a friend of mine stated "Gee, I didn't think it would be like a train going through here!" as we looked back and saw a fairly significant plume of black smoke in the air.

I live Wyoming at 6200'. Elevation is rather noticable here for naturally aspirated engines (~20% loss of power vs. sea level). Although an objective was to restore some power, it is a curiousity of mine more than anything. The engine has been set up to fuel at sea level or near it (Japan is pretty low in most areas I hear) so I'm just trying to utilize most of that. I've also been plagued with not being able to "leave things alone" - it really is a curse.

 

[CalG]

Your efforts are rewarded! Nice work!

Remember, the only time you need more power is when you run out of what you have! ;-)

Full rated power only comes at full rated engine speed, and for that, It looks like your set up works well, 5 psi is + 1/3 atmosphere!
You WIN!

 

[Ilikeurtractor]

Thanks CalG. Hopefully this thread can help others thinking about the same thing. I sure wish I could have found a thread similar to this before I started on mine :reading: Would have saved me a couple hundred bucks and the associated time on the first turbo. I suppose if I would have done my homework I could have skipped the first one anyway. Oh well.

The power gain does seem noticable and like most jobs it's worth it now that it's over (mostly) roposetoast: I hope it lasts a while. I did notice while shutting down the garage for the night that I did add a lot of "baggage" to the engine which will only make it more difficult to access. Still lots to finish up yet also.