John Deere 755 Turbo

[Nick359]

I did a little work this morning on the install project. It didn't go as well as planned. I need to get some parts to fix my welder.

Iwheel the oil line is restricted by two small holes.

 

[Nick359]

I did some more work on the turbo today. When I pulled the valve cover I thought someone might have been in the engine before. When I pulled the oil pan, some was definitely in the engine before. The oil pan gasket is no longer available. The pan was RTVed without a gasket and the bolts were loctited. I broke one, so tomorrow I will have to fix that. Anyways here is todays progress.

 

[Nick359]

I got the tractor running today. I haven't turned up the fuel yet, but I got 3 psi driving in the driveway full throttle in high range.

 

[Nick359]

Here are some photos of todays work. I still have some work to do before I take it back apart and paint it. The turbo has a good sound to it. Hopefully I can get it finished this weekend. I have to make a thumb and some forks.

 

[Nick359]

I finished the exhaust today. I don't think it is that much louder than stock. I turned the fuel up a half a turn or three flats. The turbo really woke up the tractor. I was doing some loader work today, and the engine was starting to bog a little. I looked down and I had it in high range. It runs better now in high than it did in low.

 

[kuboman]

I finished the exhaust today. I don't think it is that much louder than stock. I turned the fuel up a half a turn or three flats. The turbo really woke up the tractor. I was doing some loader work today, and the engine was starting to bog a little. I looked down and I had it in high range. It runs better now in high than it did in low.

Can you explain 'the turning up the fuel'. What/where is the adjustment and did you turn it in our out?

 

[Nick359]

The adjustment is under the "cap nut" for lack of a better term. I turned the nut that is to the right of the picture away from the other. I turned the inside nut a half turn to start. Pulling the shaft out of the pump turns up the fuel. There is also an idle adjustment, but I did not touch that. It is under a cap nut above the main fuel or on the top of the pump depending on model.

The nut that is on the left was locktighted. I could not move it, so I put a slim washer between them, I cut part of it out to get it on the shaft, then backed the inside nut against it. I will try it tomorrow to see how it works. It will be a little over one turn.

It wasn't rollin' coal with a half turn, but had some light smoke. I still had 3 psi boost in high range full throttle full hydro pedal.

 

[kuboman]

The adjustment is under the "cap nut" for lack of a better term. I turned the nut that is to the right of the picture away from the other. I turned the inside nut a half turn to start. Pulling the shaft out of the pump turns up the fuel. There is also an idle adjustment, but I did not touch that. It is under a cap nut above the main fuel or on the top of the pump depending on model.

The nut that is on the left was locktighted. I could not move it, so I put a slim washer between them, I cut part of it out to get it on the shaft, then backed the inside nut against it. I will try it tomorrow to see how it works. It will be a little over one turn.

It wasn't rollin' coal with a half turn, but had some light smoke. I still had 3 psi boost in high range full throttle full hydro pedal.

The reason I ask is I have the same engine and pump on a f935 mower. I turned the adjustment out and all it seemed to do is pour black smoke when it started to pull down. In fact it seemed to bog once the smoke started. I turned it back in some and it seemed to have more power without the excessive smoke and bogging. Seems to be a very fine adjustment. That adjustment is also spring loaded. There is a spring loaded pin inside that small screw with the 2 jam nuts.

 

[Nick359]

Here is the long awaited video of the turbo.

YouTube - 002.AVI

 

[moship]

Thanks for posting the video and the details of the installation along the way.

Did you do any before and after performance measures, such as time it takes to climb a hill?

What is the max boost set at? It looks like 5 psi on the video, but there is a bit of camera shake.

 

[Nick359]

I tried to find a pto dyno in my area, but the only one I could find could not measure low enough for my tractor. If I find one later I can measure it and compare it to the claimed 15 pto hp stock.

I did not climb the hill in my back yard to time it when I started the project. It was covered in snow.

I got a max boost of four and it will hold three when driving in high range. I climbed the hill over the weekend in low and it was a steady three not running it full hydro and a little over 3/4 throttle. It could climb the hill in high, but it was too bumpy and I was pulling logs out. I never set the boost. The turbo's wastegate is set at 11.6 psi. I will adjust the fuel more or less and see what the engine wants. I think it is pretty close now, but I need to get on an egt guage and a temp guage.

If anyone has a 755 in the area we can do some comparisons.

 

[Bigkrank]

Since it's on a diesel you can deactivate the wastegate if you desire. You can also shorten the connecting link to increase the pressure also. Yours is in a stock application so it'll probably be fine just the way it is. The twin scroll makes a world of difference in your application.

When we ran one of those in competition we had a longer arm on the wastgate and a heavy spring on it. The wastegate tubing was plugged. Ran about 40# boost, when you get over 30# they really wake up. Do not try that on a gas (unmodified) engine boys & girls.

 

[PCABE5]

Nice work. Sounds like your going to be happy with your turbo results. I think I will be happy if I can get 3-5 psi out of mine. Rough guess is at 3 psi you added ~3hp. You probably won't see your full boost numbers until you can really put it under a good load.

Most impressive and thanks for posting your project.

 

[Nick359]

So far I put over five hours on the tractor since installing the turbo. It runs a lot better than before. When I plowed the garden, it would hold four psi in low range. It sounds like a larger piece of machinary than it is.

 

[kuboman]

So far I put over five hours on the tractor since installing the turbo. It runs a lot better than before. When I plowed the garden, it would hold four psi in low range. It sounds like a larger piece of machinary than it is.

Did you play with the smoke screw?

 

[Nick359]

I put about one turn on the smoke screw. I don't want to go more until I put my pyro on it and a temp guage.

I will see how it does mowing in a few weeks.

I don't want to start breaking parts now because I can do loader work in high range either.

It seems to be a bit thirstier than last year too.

 

[Nick359]

Update

I have the fuel turned up 6 flats or 2/3 turn.

I finally got to mow my grass and my neighbor's. It was tall and wet. I had the tractor in high range. I had no problems mowing the hill that bogged the tractor low range pre turbo.

I bought a five foot box blade. I didn't have any issues pulling that, but I didn't have it before the turbo istall.

 

[Kevin M]

Nice job ! I love the idea being a fellow 755 owner , Can you give us more info on the turbo , Maybe where to get one ? What they are used on ?

 

[Nick359]

I ordered the turbo from Ebay. I ordered from someone who claimed 3 to 5 day shipping from California. Two weeks later it came from China.

I got a Mitsubishi TD02 twin scroll. It was harder to hook up the twin scroll over the single. I was told they are better, but I would be willing to try the single. Going with the single will save you about $100.00. Small Garrett's will work too, but they cost more.

My neighbor has a 455 (I think) and it has the same engine with the exhaust manifold exit on the top between the second and third cylinder. That would make for an easier hookup.

Let me know if you have any more questions. I didn't want to bore everyone with every detail along the way.

 

[Kevin M]

You will never bore me with details , That's the important stuff. I would consider this with my 755 but I would like to tuck it under the hood and sheet metal. I wonder though if the turbo would get hot enough to melt the hood ?