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Looks great. It will be interesting to see what the difference will be on the lugging up the hills with the stock hydro. Thanks for making an attempt to make these units a little more "all around" useful. That's for sure Polaris can't figure it out.
 

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Discussion Starter · #4 ·
I still have some small details to finish up but I got it all together and did some test runs. I'm running 6 psi. It's hard to tell how much power I gained because the hydraulic drive motor can still only generate the same limited amount of torque. It does accelerate faster and maintain more speed on hills to a certain point, but on the steepest hills it still runs out of torque in high range. It maintains max rpm during acceleration without any trouble, where before it would bog down the engine. I think it would be a great improvement for running PTO attachments, but I don't have PTO. I have several ideas for improving the trans. I'll post more about that later.
 

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Discussion Starter · #7 ·
We won't likely ever see a bolt on kit, I don't think Brutus sales were high enough to cover development and production costs. The change to the Kolher engine for 2015 makes it even less likely, and those engines have unit injection pumps that are not so easy to increase fuel. PPE would be the ones to bug about it, they do kits for the Ranger Diesel.

I followed PPE's instructions to adjust fueling. For their kit they recommend 1.25 turns out on the Rated Fuel Delivery screw. I'm at 1.5 turns out. I went two turns and got lots of black smoke but no noticeable increase in power. I can't get EGT above 850 no matter what I do. There is another adjustment called Torque Fuel Delivery, I'm trying to find more info on that before I mess with it. I suspected possible intake or exhaust restriction so I did a brief test with intake and muffler removed, didn't notice any difference except more noise. At 6-7 psi I should be able to get at least 34 HP, I don't think I'm even close to that.

I've completely eliminated the HP management function from the hydrostatic pump by adding a screw to close the gap between the command lever and pintle lever. It allows me to put maximum load on the engine. From a standing start I can just about stall the engine if I push too hard before the turbo spools up. I've also changed the minimum displacement stop in the hydraulic motor from the stock 9 degrees to 6 degrees. The result is increased top speed in low range of 22 MPH, with the same starting torque. There is a torque reduction after the motor shifts, but the new low range high speed torque is still 50% higher than the stock high range high speed torque. This change also increases the high range speed to something like 48 MPH, but because of the lost torque it makes high range pretty much useless. For my use I am happy to leave it in low range. The final result is that I can do 15 MPH up hills where I could previously only do 10 in low range, and I can do 22 on flats without shifting to high. I'm pretty happy with the way it runs now.

Pictures of the modified command lever and new motor displacement limiter.
 

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Discussion Starter · #8 ·
I spent some more time with the fuel adjustments and learned a few things. There is no way to increase fuel to optimal levels under boost without also having excessive fuel with no boost. The result is excessive smoke when accelerating until the boost builds. It seems this is a fairly common problem when turbocharging NA diesels. The solution is a boost compensated injection pump. I'm not sure if Yanmar makes one that will fit this engine. For now I have it adjusted to where I can maintain 3600 RPM on my steepest hill with full forward command and the HP management spring disabled. It smokes a little bit on acceleration, but I can live with it. It accelerates faster than the Ranger diesel and stays ahead until it tops out at 22 mph. I'm actually really impressed with it. It'll spin the tires and do donuts now, I don't think I could do that before. The torque fuel delivery adjustment seems to be for preventing engine stall. It doesn't seem to have any effect on the normal performance of the engine.
 

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Interceptor, I'm extremely interested in what you are doing! I'm not a mechanic and my 2013 Brutus HD PTO is the first deisel I've ever owned. Can you share with us an idea of the cost to turbo charge this machine and how I would get started?
 

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Discussion Starter · #10 ·
It probably cost me about $500, but I did all the fabrication myself, used a used turbo, and scrounged most of the parts leftover from other projects. If you have to buy everything new and pay someone to do all the work it would probably be $3-4000.

You need to start by choosing a turbo, they are not universal, the piping and plumbing will need to be custom made for the specific turbo you choose. It's kinda difficult to find a turbo that's not too big for a 900cc diesel. The RFH3 that I used is from a 660cc (gas) Suzuki car. They are very common in Japan, but were never sold in North America except for some Arctic Cat snowmobiles that used the Suzuki engine. A Mitsubishi TD02 would be a good match as well, but is just as uncommon. You can find cheap Chinese clones of these turbos for a couple hundred, but I have more trust in a used OEM one. If you run most of the time at full throttle and aren't concerned about lag you could probably run a larger turbo with good results. PPE uses a Garrett GT12 for the Ranger turbo kits. Looking at the specs it's way too big, but it works and is readily available, I think they are about $800 for a new one.
 

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Interceptor, I use my machine at 9500 feet above sea level. I bought it primarily for blowing snow, but I use it in the summer for general hauling, towing trees, etc.. I am not too interested in speed, although it would be really nice not to creep up the road, which is only a slight upgrade when going to see neighbors. I do bog down, almost to the point of stalling, when I am blowing snow and climbing one of two STEEP hills in my driveway. Do you think if I changed the command lever to the new style that would solve my power issues under load or do you think I should seriously pursue the turbo modifications? By the way, how did you get to be so darned knowledgeable about these machines?
 

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Discussion Starter · #12 ·
If the engine cannot maintain a steady RPM under load, that's lack of power from the engine and a turbo will help. A likely example would be engine bogging or stalling while blowing snow like you described. The command lever problem has a completely different symptom. The engine will rev freely and it will seem as if the transmission is slipping. You will get the high pitch whine with slower than expected travel but no drop in engine speed. In this case a turbo will do nothing for you. In fact here at near sea level the transmission cannot really utilize any more power than the engine makes in stock form. The spring on the command lever limits the amount of HP it can use. In other words there is no way to bog or stall the engine while just driving, unless the transmission is modified. At 9500 feet though you are making considerably less power and may run into a situation where the drive requires more power than the engine makes. A turbo would get your power level back up to where it would be at sea level. If I were at 9500 ft and blowing snow I wouldn't think twice about it, it would get a turbo. But of course mine had a turbo when it was only two weeks old so it may not be best to take advice from me.

I've been an industrial equipment mechanic for 20 years. I suck at a lot of things but I'm pretty good with machines.
 

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Ran across this
showing a 2013 Brutus with "IHI RHF3 turbo", author comments"The engine is stock, the injection pump is turned up."
 

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Discussion Starter · #15 ·
Kev, that's my video. Unfortunately it doesn't really show the steepness of the slopes or the travel speed. I was just playing around with a new camera.
 

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Kev, that's my video. Unfortunately it doesn't really show the steepness of the slopes or the travel speed. I was just playing around with a new camera.
So better at hill climbing, improved top speed on level ground, or both?
 

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Discussion Starter · #17 · (Edited)
It's hard to quantify the improvement because I did a lot of modifications in a short period of time, and I think the machine was less than two weeks old when I did it. I suspect it's making about 30-32hp. The turbo alone doesn't do anything for top speed. The modifications to the drive motor and command lever are what really make the difference, but they require the extra power from the turbo in order to be effective. One or the other alone would not substantially improve performance. It will easily do 22mph in low range, and we always use low, it's as fast as we need to go on our property. High range will theoretically do just over 50 mph, but the land does not permit it due to hills and lack of open space. I ran it down the paved road once and I let off at 40 mph because it just didn't seem safe at that speed. I don't think it has enough power to actually reach 50 unless going downhill.

Ultimately the limiting factor in the performance of these things is the hydrostatic pump/motor. It is prohibitively expensive to replace them with something that can make use of additional engine power.

I just realized I didn't really answer your question. It's improved all around. Much better acceleration, faster hill climbing, and faster top speed.
 

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Hope Interceptor is still on here, I am replicating some of his work here.

I am doing the command lever mod and setting high idle for 3750 RPM as the spec allows. Richening the fuel setting 3/4 th's a turn.

Just curious about his thoughts on that and why he reduced the flow on the piston pump.
 
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