kubota vs. kioti

[LD1]

So, a "horsepower guy" says 8.5 mph. Anyone from the "torque camp" want to give their answer?

Are you looking for more than 1 answer?

 

[tomato coupe]

Are you looking for more than 1 answer?

Implicit in your answer is that the tractor is operating at 2700 RPM, since you are using 50 HP in your calculation. High torque occurs at 1600 RPM, however, so I am interested if someone in the "torque camp" calculates a different max speed by operating the engine at the torque peak.

 

[SPYDERLK]

You know that you will not get max speed at torque peak. Max is only available by gearing to correspond with power peak.... unless a real world transmission gets lossy at some ratios.

 

[tomato coupe]

You know that you will not get max speed at torque peak. Max is only available by gearing to correspond with power peak.... unless a real world transmission gets lossy at some ratios.

Your assertion is essentially what LD1 has stated in many of his posts, i.e. "engine horsepower is more important than engine torque" in regards to maximizing the work done by a tractor. I think several posters will disagree with you, and they will argue that high torque is more important. I would simply like to hear what their answer to the problem is.

On a more general note, the problem I posed was chosen for a few reasons:

1. It is pretty simple to solve.
2. It mimics the model used to define horsepower, where a horse lifts a certain amount of weight a certain height in a set amount of time.
3. With a few basic assumptions, the theoretical answer can closely match reality.
4. The horsepower and torque curves are from a real engine -- they are not peak values pulled out of thin air.

Cheers

 

[LD1]

You know you won't get anyone in the " torque" camp to answer once they put pen to pad. But you will likely get lots of excuses, not real world, put a 15k rpm bike engine in a tractor answers.

 

[LD1]

I've got one more question for the torque camp...

What is better. An engine that can make 1.6 million ft-lbs of power in one minute, or one that can make 2.6 million ft-lbs. (Since you guys like torque so much)

 

[TomSeller]

Divide that by the tractors weight, and you get the vertical distance it can lift itself in 1 hr measured in ft. .

Kubotas do well in this regard.

 

[dragoneggs]

Your assertion is essentially what LD1 has stated in many of his posts, i.e. "engine horsepower is more important than engine torque" in regards to maximizing the work done by a tractor. I think several posters will disagree with you, and they will argue that high torque is more important. I would simply like to hear what their answer to the problem is.

On a more general note, the problem I posed was chosen for a few reasons:

1. It is pretty simple to solve.
2. It mimics the model used to define horsepower, where a horse lifts a certain amount of weight a certain height in a set amount of time.
3. With a few basic assumptions, the theoretical answer can closely match reality.
4. The horsepower and torque curves are from a real engine -- they are not peak values pulled out of thin air.

Cheers

This is getting good! Thanks Mr. Tomato. As a mechanical engineer, I am truly enjoying this thread regardless of how off track it is going.

 

[LD1]

Perhaps the title should be changed to HP vs TQ. Since I think that's what the majority of it is. Wouldn't surprise be a bit if it reached 500 posts.

 

[paulfun9]

Add to your problem what happens when you are pushing the machine by hauling more weight than the machine can carry at peak RPM such as when you are stuck down gearing because the engine cant hold the peak RPM going up the hill.

Math is fun but when real world problems are added the formula will be different and the outcome wont always be so obvious.



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