So I was talking to a friend this morning... 2am... I realize that I understand roughly in my head what torque and horsepower do... but was exactly does each one do... in Laman's terms.
Any help would be appreciated! Just trying to learn somethign and expand my knowledge to a better understanding.
Full Version: Horsepower and Torque.
Good morning. I'm sure someone can post a diagram to help illustrate this. But basically torque is a twisting force, horsepower is a measure of the ability to do work, which is moving a force (weight) through a distance in a certain time.
Horsepower ( the term and the definition) was invented by Isaac Watt, the inventor of the steam engine, to be able to sell engines by showing that they could do the work of x number of horses, which was the principal motive force at the time. He actually measured how much work horses could do, pulling weights for a distance and how fast. He came up with a figure of 22,000 feet-pounds per minute or maybe it's pound-feet per minute. For example: 220 pounds moved 100 feet in one minute. To sell his steam engines, knowing that someone, somewhere would actually go out and find the biggest, strongest horse they could to make a liar out of him if they could, he used 33,000 foot-pounds per minute as his "horsepower" upping the power output 50% over what his measurements showed a horse was really capable of so no single horse would have a chance of beating a steam engine that he rated at 1 horsepower.
Torque, as with a torque wrench, is a twisting force. 50 pounds of force applied at the end of a one foot handle is 50 foot-pounds, at the end of a two foot handle is 100 foot pounds.
The diagram is called for to illustrate the device for measuring horsepower when your force is rotary, as from the end of the crankshaft. I think it is called a "Prony brake" Okay, wikipedia has it as "de Prony brake" with diagram.
Hope that helps.
Horsepower ( the term and the definition) was invented by Isaac Watt, the inventor of the steam engine, to be able to sell engines by showing that they could do the work of x number of horses, which was the principal motive force at the time. He actually measured how much work horses could do, pulling weights for a distance and how fast. He came up with a figure of 22,000 feet-pounds per minute or maybe it's pound-feet per minute. For example: 220 pounds moved 100 feet in one minute. To sell his steam engines, knowing that someone, somewhere would actually go out and find the biggest, strongest horse they could to make a liar out of him if they could, he used 33,000 foot-pounds per minute as his "horsepower" upping the power output 50% over what his measurements showed a horse was really capable of so no single horse would have a chance of beating a steam engine that he rated at 1 horsepower.
Torque, as with a torque wrench, is a twisting force. 50 pounds of force applied at the end of a one foot handle is 50 foot-pounds, at the end of a two foot handle is 100 foot pounds.
The diagram is called for to illustrate the device for measuring horsepower when your force is rotary, as from the end of the crankshaft. I think it is called a "Prony brake" Okay, wikipedia has it as "de Prony brake" with diagram.
Hope that helps.
if you want to demonstrate to him what torque is. have him sit in a chair, and push on his shoulders so as to push his back into the seat. This is what torque in a car does.
This should be helpful in getting you started:
http://vettenet.org/torquehp.html
A "friend" forwarded it to me when I asked pretty much the same question.
http://vettenet.org/torquehp.html
A "friend" forwarded it to me when I asked pretty much the same question.
He asked for Layman's terms, I'll try.
Torque is what you feel when you step on the gas. Basically the power of the explosion pushing down the piston. If you have the same explosion pushing on the piston, A longer stroke on the crankshaft means more torque. Torque will fall off when engine mechanicals no longer have the ability to maintain the size of the explosion.
HP is the ability of the engine to maintain torque as engine speed increases. In other words, to maintain the size of the explosion to higher rates of Torque production, as in RPM's. So the ability to turn more RPM's mean higher HP. You won't feel this when you step on the gas, but as you wind thru the gear.
Does that make sense?
Torque is what you feel when you step on the gas. Basically the power of the explosion pushing down the piston. If you have the same explosion pushing on the piston, A longer stroke on the crankshaft means more torque. Torque will fall off when engine mechanicals no longer have the ability to maintain the size of the explosion.
HP is the ability of the engine to maintain torque as engine speed increases. In other words, to maintain the size of the explosion to higher rates of Torque production, as in RPM's. So the ability to turn more RPM's mean higher HP. You won't feel this when you step on the gas, but as you wind thru the gear.
Does that make sense?
Force is also measured in Newtons and if you applied a force of one Newton on an object in the direction of motion to move it in a straight line for one meter, then you will have done work on the object equal to one Newton-Meter or one Joule. (The work done on an object to move it in a straight line when the force is applied in the direction of motion is W = F*d.) If this work was done over a period of one second, then the power required to do it was one Joule per second which is equal to one Watt.
If you apply a force of F lbs perpendicular to a lever arm of length d ft., then you are applying a torque equal to F*d to the arm. The circumference of a circle with radius d ft. is 2*pi*d so if the force F causes the arm to rotate one revolution, then you have done work equal to F* (2*pi*d) which after some rearranging is F*d*2*pi or Torque times 2pi. So the work done per revolution is Torque times 2 pi.
Work = (Torque*2pi) / revolution. If we have r revolutions, then the total work done is
[(Torque*2pi) / revolution] * [ r revolutions] = Torque*2pi*r. Now if these r revolutions occurred in one minute, then the Power required to perform this work was Torque*2pi*r divided by 60 seconds
= (Torque*2pi*r) / 60 s = Torque*2pi* (r / 60s) or Torque*2pi*rpm and which has units of ft*lbs /s.
And since there is one hp per 550 ft*lbs / s we have
Horsepower = [(Torque*2pi) *(rpm)] / [ (550 ft*lbs / s)] where rpm = revs/60s
Therefore Hp = Torque*rpm / 5252
this is engineer central, WHAT HAVE YOU DONE!!!
How about this:
This is how my teacher explained it to us before he went into the Force/Power explanation.
Horsepower is the top speed of how fast your car can go down the road and torque is how fast your car can get to that top speed.
Of course there is always a trade off (ratio). More torque means you have less HP or the more HP means less torque. Finding a good balance between the two is the grail to search for.
Big trucks have monster torque but not a lot of HP in comparison to their torque.
This is how my teacher explained it to us before he went into the Force/Power explanation.
Horsepower is the top speed of how fast your car can go down the road and torque is how fast your car can get to that top speed.
Of course there is always a trade off (ratio). More torque means you have less HP or the more HP means less torque. Finding a good balance between the two is the grail to search for.
Big trucks have monster torque but not a lot of HP in comparison to their torque.
While I understood.... most of the other posts... the last one is exactly what I was looking for, for my friend to understand. She wanted a bare bones basic explanation. Thanks guys because the other ones definitely helped me understand it a little more.
812 lbs/ft of torque vs. 273 is why the Audi R10 TDi can outdrag (that's straightliner terminology for "run away and hide") the Porsche RS LMP car down any straightaway, despite a 25% weight penalty. The Cap'n
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.