How much HP do I need?

[CJBOTA]

I have been running my Rears 300 gallon Airblast Orchard sprayer with my MX5100 for about 5 years?. The problem is the MX5100 can barely make the 540 at the pto on level ground. My orchard consists of 10 acres of peach trees. (About 3000 trees) With the tank full & the 3'diameter blower running, when I start up a hill the rpm will drop a little below 540 rpm. I can slow down a little and the rpm will come up a little but then I am wasting chemicals. I need full ground speed in low range to deliver the correct amount of chemicals.
I am sure the M7040 would give me enough pto hp to run the sprayer but I don't like the idea of going to a tractor that big in my orchard. I have to make a lot of tight turns so I want to stay as compact as possible. So my question is do you think the L6040 with 10.5 more pto hp will give enough more hp to run my sprayer at full540 rpm. I haven't checked the actual dimensions but I am guessing the L6040 is considerably smaller than a m7040.

 

[Grandad4]

The GL6060 Kubota would give you about a 10-15% bump in pto hp on basically the same size chassis as your MX and would also offer the upgraded HST that would give you more precise speed control. Don't know if that's enough to make the difference for you.

Wondering if it would make any sense to replace the sprayer instead of the tractor. Rears makes sprayers with 33" and 38" fans, but the 33" ones can be configured with a lower fan pitch to draw less hp., the smallest ones rated for 35-40n pto hp tractors. There also seem to be some other brands that offer sprayers with lesser hp requirements. Keep in mind I don't know anything about orchards, sprayers or your particular requirements!

 

[gladehound]

CJBOTA - How fast are your traveling on the flat at 540 PTO RPM and is this your desired speed? To what speed do you currently have to drop to on your hills in order to maintain 540 PTO RPM? How much does the tractor and sprayer weight? From this information, I might be able to get a rough estimate of how much more HP you would need to maintain the same speed on the hills that you currently go on the flats.

one edit - it would also help to know how many HP the sprayer is supposed to take just to run it. Thx!

 

[CJBOTA]

My Mx5100 is a HST and I try to spray at 2.5 mph. That happens to be low range full pedal on my tractor. My tank holds 300 gallon of water which weighs 2400# plus I estimate the sprayer weighs 1600#. So I am pulling about 4000# plus the weight of the tractor. This set up sort of works on level ground. As my trees have grown it has become a little harder to blast the chemical through them. Also, I should say my Rears sprayer is awesome. The blades are adjustable, I have them in the low position, I wouldn't mind moving them to the middle range, but the mx5100 can't make 540 rpm on the pto in that position. The sprayer also has a two speed gearbox, I have to run it in low range to make 540 rpm at the pto. So the sprayer has plenty to give if you have enough hp. My trees are semi dwarf so I don't need to blow the leaves off the trees. But I need to make sure I am blowing the chemical thru the tree against a 3 or 4 mph wind. I am thinking another 10 hp might get me up the hill. The 7040 would give me some margin but I just think that tractor is huge.

 

[Farmer495]

A 7040 utility is not a small tractor.

Kubota offers "orchard" tractors, here is a M7040DTNH1

Orchard M7040DTNH1
Price is in CDN money, didn't look up US site.

 

[RedNeckRacin]

Personally I would get the heck away from that HST tranny if you bump up in size. It takes considerably more hp to power that than a manual transmission. How much more I really can't tell you..

 

[CJBOTA]

Redneck,
I have really enjoyed the benefits of HST with the mx5100. However, I agree with what you are saying. I like how my mx5100 can work like a skid steer. But as you go bigger the HST loses it's appeal. Not only does it eat up engine power, I am also concerned about long term maintenance. Replacing an HST pump is probably insanely expensive. So if I go bigger I think I will consider moving away from HST.

 

[corl]

Can you increase fuel into the tractor by adjusting the fuel pump to give you more horsepower. It is possible to do so with a turbocharged engine. (Demonstrated on a New Holland by Ted @ EverythingAttachments video - 25% more power at PTO) Only problem is increased heat generated. Turn up fuel until you get exhaust gas being visible

The MX5800 has 50 PTO HP. Get your dealer to demo whatever you buy to make sure it does your job. The engine is the same as you have, just a different turbo. Since you don't have a tier 4 engine I bet you can get that much HP by turning up your fuel.

 

[Fallon]

I love my HST, but it does have its drawbacks. Particularly the fact it eats about 15% of your HP. For your situation a GlideShift or PowerShift transmission sounds like it make more sense.

 

[CobyRupert]

Thinking out loud here: If the hill causes rpm to dip (say) 10%, (assuming you're holding hydro pedal steady) won't both the pump's gal/min and tractor's ground speed (ft/min) also dip 10% too? That is, won't your application rate (gallon/ft) be similar?
Or are you now getting less area coverage because of a pressure drop? (I guess this gets into pump curves, i.e. the pressure vs-flow-rpm relationships)