CHOP SHOP
Well-Known Member
Thats how they measure torque with an electric motor. Most at 0 rpms with no thermal failure.
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Help Support Hardline Crawlers :
Torque vs. Horsepower
- Thread starter Trailtoy1993
- Start date
Thats how they measure torque with an electric motor. Most at 0 rpms with no thermal failure.
The acceleration of your moving element is a result of your net force or torque. If you are creating torque but not moving, then what ever is preventing you to move "has an equal but opposite force". Its just like pushing on a brick wall. Push all day with as much force as you can, if the wall isn't moving then you are not generating any power.
Sorry I am an ME and size electric motors for automation applications all day. All of this is right up my alley.
Binder
Well-Known Member
I don't agree. I've had this conversation with other engineers who would also disagree.......I do understand where you are comming from but "acceleration" is moving something and cannot be achived by torque alone, you have to add RPM wich adds up to HP.
Exactly!...You can have torque and not move AND have no power. If it turns there is RPM and there is power....
Hey whatever. At that level it's just a matter of terms being used. I only bring up these type of situations to help understand what these terms actually do and how they relate to a tow rig. In the end the acceleration curve will match the power curve and not the torque curve. That was the point in the first place.
Trailtoy1993
Well-Known Member
Holly wah! I was figuring this was just gonna die out since it was a re-post!
Trailtoy1993
Well-Known Member
I don't agree. I've had this conversation with other engineers who would also disagree.......I do understand where you are comming from but "acceleration" is moving something and cannot be achived by torque alone, you have to add RPM wich adds up to HP.
Exactly!...You can have torque and not move AND have no power. If it turns there is RPM and there is power....
Hey whatever. At that level it's just a matter of terms being used. I only bring up these type of situations to help understand what these terms actually do and how they relate to a tow rig. In the end the acceleration curve will match the power curve and not the torque curve. That was the point in the first place.
And I don't agree, an electric motor makes it most torque at zero rpm of course but that is when the motor is started and making its attempt at accelerating from zero rpm.
You yourself stated that Horsepower is simply another way of saying torque at rpm so if Horsepower is based off of torque.... How is it more meaningful then the torque???? As it relates to a tow rig low rpm torque is what gets your load moving off the blocks and going again, why it is much nicer to pull a heavy load with a big diesel than a turbo toyota motor. Again, the four banger is lots of fun, but at low rpm you sure notice that it is not a "torquer" of a motor. I still fail to grasp your contention that "425 hp is 425 hp" I really don't get how you figure that a 350lb-ft motor with 425 hp could possibly pull like a 1000lb-ft 425hp motor if like you said in the other thread "all other things like weight and gear ratio were equal" ??? ESPECIALLY the gear ratio part. The four cylinder just doesn't have the nuts down low to pull if the gear ratios were equal. Big diesels with massive low end torque can be bogged down and then that big torque goes to work pulling back up to speed, small low torque engines bog and just stay bogged or die out because they don't have the big twisting force to pull back up to speed.... Please help me understand your point of view a little better sir.
Binder
Well-Known Member
All things being equal as in the power curve of both engines being the same. Of course they are not and there is the differnce. I've noted specifically where torque importance comes in as best as I think I can. Remember towing a trailer there is a power transmission involved and due to the characteristics of a internal combustion engine you will almost always have adequate torque at the wheels. A electric motor is different and though the same rules of HP and torque apply the specific scenario could be completely different.
425 HP vs 425 HP could have a completely different power band. Until that information is giver 425 HP has a specific ability to accelerate a specif weight so they are equal......With more information input the differences come out.
WHITE TRASH1
fruit stripe
The cat in my vulva only puts out 435hp but over 1500 ft lbs of torque and it does all of that under 2k. This argument is retarded. :flipoff:
messix
Well-Known Member
so why is a 300hp deisel more desirable than a 300 hp gas motor in a tow rig?:stirpot:
Binder
Well-Known Member
Which one will last longer and get better fuel economy?:;
Binder
Well-Known Member
Nobody wants to hear about your vula.:flipoff:
WHITE TRASH1
fruit stripe
Binder
Well-Known Member
That's how a dumb negro spells *****.:haha:
Alpine4x4
Well-Known Member
I'm thinking theres more to it than that.
If high horsepower is more desirable than why don't they just run gas engines in big rigs?
WHITE TRASH1
fruit stripe
Usable power range. Diesels produce more torque at lower speeds, gearing doesn't have to be too steep in order to pull.
Gas engines produce less torque but can operate at high speeds. More gearing is required to get the same torque as a diesel. Higher RPMs means more piston strokes = more losses to friction, more heat, less efficient.
Binder
Well-Known Member
Who said high horsepower is more desireable? I simply expained that HP is what make a tow rig accelerate.
Fixed
Newton's Laws
1. In the absence of a net force, the center of mass of a body either is at rest or moves at a constant velocity.
2. A body experiencing a force F experiences an acceleration a related to F by F = ma, where m is the mass of the body. Alternatively, force is equal to the time derivative of momentum.
3. Whenever a first body exerts a force F on a second body, the second body exerts a force −F on the first body. F and −F are equal in magnitude and opposite in direction.
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TreeClimber
Well-Known Member
This question also relates to the amount of Kinetic energy available from a given fuel. The higher the fuel's energy, the more work it can generate. Since diesel generates on average 15% more energy than gasoline, it can also be expected to provide more economy for a given amount of energy expended, and because of it's high compression ratio generates a very high thermal efficiency. Ergo, a comperable horsepower diesel and gas engine, you will have better effeciency (mileage) with the diesel.
Glenn
Well-Known Member
This, Binder, is part of why I think the inline 6 is a better choice for diesel engines than the V8.
Binder
Well-Known Member
Where did Newton say torque?
I'm not following you on why the efficiency of different fuels has anything to do with the arrangement of cylinders but OK whatever.
