Horsepower at 7000 ft altitude

bobbigbear

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Looking at the 2501 with Land Pride Rotary cutter RCR 1260. I'm in Big Bear CA at 7000ft altitude. Will the 2501 have enough horsepower at this altitude to operate?
 

North Idaho Wolfman

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Looking at the 2501 with Land Pride Rotary cutter RCR 1260. I'm in Big Bear CA at 7000ft altitude. Will the 2501 have enough horsepower at this altitude to operate?
Altitude and a naturally aspirated diesel is a very minor issue.

A gasoline engines loss is much greater.

One formula is a loss is about 0.5% per 1000 ft due to less oxygen.
 

SRG

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Altitude and a naturally aspirated diesel is a very minor issue.

A gasoline engines loss is much greater.

One formula is a loss is about 0.5% per 1000 ft due to less oxygen.
Does that have to do with the higher compression ratio of a diesel?
 

North Idaho Wolfman

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Does that have to do with the higher compression ratio of a diesel?
They say it has to do with a lean fuel mix where a gasoline engine is rich fuel mix and becomes too rich when you go to where there is less oxygen, where a diesel does not care as much.
There is very little info out there on naturally aspirated diesels at altitude, most info is turbo based. :(
 
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Jchonline

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I am at 8600 ft and looked at the effects of altitude on tractor performance closely. You are loosing closer to 3% per 1000 ft in a non turbo Diesel engine.
https://www.tractorbynet.com/forums...tor-buying-advice-47-acres-6.html#post5012202 (post 53).

There are a number of factors involved, but I bet you will have one smoking machine at 7000. Personally I would get a much higher HP machine than you need, or get one that is turbocharged (which usually means higher HP range). Deere makes a couple 3 series 38 HP turbocharged machines. I think for Kubota it is the MX or Grand L at 50+ HP lines to get the TC. That said you could probably find something like a L3901 or L4701 that is more HP than you need to make up for the loss. With a turbocharger, the loss is negated.

From an experience standpoint..the M62 is turbocharged and 63HP. I notice no issues with power, starting, running, or smoking at all. I dont use a mower, or currently use it for HP intensive tasks (mowing, snow blowing, etc). I tested a number of non turbo machines at about 5300 ft. The Kubota BX was terrible. The B2650 was acceptable with no implements on it on flat ground. I even thought the L47 TLB could use more power for its weight (no turbo).

It sucks, but we are the ones that choose to live at altitude :). The best thing to do is get a few machines to Demo on your property. This would quickly tell you how they perform.
 
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PaulL

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With a turbocharger, do they automatically turn up the boost to a consistent pressure in the cylinder, or would it be possible to manually turn up the boost to compensate for the thinner air? Seems like if you did that you shouldn't lose any HP at all with altitude.
 

Jchonline

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With a Turbocharger you dont loose any HP at altitude already. There is no reason to adjust it (unless I miss understood your comment).
 

PaulL

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OK, so with turbocharger it's running constant boost pressure irrespective of ambient air pressure - so it's automatically compensating for the thinner air?
 

SRG

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I stumbled on this while reading through some technical specs (Yanmar engines) about my green machine (made me think of this thread)....

 
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greenacresnorth

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a turbo engine will compensate with either a waste gate that builds a pressure compared to surrounding atmosphere and a set spring rate, and or a aneroid fuel control device on the fuel pump, this regulates fuel rate against a spring referencing manifold pressure on a diaphragm compressing said spring. both systems will automatically normalize with no setup for most altitudes. not that being said, I have done many custom fuel tables for diesel trucks and equipment operating 10,000' plus ALT Density, actually just finished a x15 cummins tune set for a crane working on top of a gold mine called La Rinconada in Peru, were the average DA is over 16,500'.