define torque

[Eric Kelcher]

The way I had it explained to me years ago was that torque told you how much you could move, hp told you how fast you could get it moving.

[tcchin]

Torque is force x distance and has the units of lbf-ft or N-m. Torque is an expression of work or energy. In other words, the amount of energy you imparted on an engine while torquing cylinder head bolts (stored as preload in the head bolts and lost as friction) may be the same as the amount of energy you expended while pushing a boulder up a hill. It's all about force and distance.

Power can be seen in several ways, depending on your available variables. It could be seen as force x velocity (as in how fast you can push a fairing through air or how fast you can run under water), or it can be seen as the time rate of change of energy (how fast a given volume of water will boil, or how quickly an object's kinetic energy can be increased). Power is work (energy, torque, lb-ft) over time (sec).

Horsepower is an arbitrary value that dates back to the early 19th century. It represents the average amount of power that a horse can produce. Specifically, one horsepower is 550 lb-ft per second, meaning that a horse can lift a 550 lb weight one foot in one second. Notice the units here: feet, pounds and seconds.

So where does 5252 come from? It's an approximation of 550 (from 550 lb-ft/sec) multiplied by 60 (sec/min) divided by 2pi (radians/revolution), used when calculating the instantaneous horsepower value of an engine that's producing a given amount of torque at a given engine speed.

Why the terms 'low-end torque' and 'high-end power' have evolved culturally into the implication that torque is exclusively a low-engine-speed phenomenon is a mystery to me. Torque and horsepower and not independent variables. They are both present all the time, but power just happens to include an engine speed component.

[Super Dave]

I'm still faster than you guys.... :P

Few people experience "HP".  Maybe at Daytona.  But torque you can feel.  Do you guys recognize the difference?  I don't teach schools with equations.  It has no feel.  

[cuda]

I'll chime in,  Torque is the force behind one repetition, horsepower is torque X rpm.  So if an engine makes 1/2 the power each time it rotates than another engine but it revs to more than twice the RPM then it will make more horsepower.  The problem is the power created until it gets into the high revs.  In the end, assuming you can keep the revs up on a machine, only HP matters.  But if you can't then some lower HP engines may be using more HP at a given time than a higher HP engine if the higher one is lower in RPM at the time.  After all, you don't use the power an engine is capable of, use use what it is putting out at the time.  

[Xian_13]

HP is work,
Torque is force.

The answer to WHY
is why not



Now everyone lets define Irony


:D X

[K3 Chris Onwiler]

You're all missing the most important detail.  Rob has a girlfriend?  Is her name Louise? ;)

[EX#996]

You're all missing the most important detail.  Rob has a girlfriend?  Is her name Louise? ;)

LOL!!!!

 ;D

[dwilson]

This thread is getting esoteric enough that I'm getting the desire to read "Zen and the art of Motorcycle Maintenance", again...

[Mark Bernard]

I was talking with my boyfriend Rob #940 last night.  I asked him to give me a definition of "torque" and he could not.  I got an explaination but not a true definition.  Can any of you give one, without the aid of Websters?

Hey Rob, I like your wet little....pug.  Yes, pug.  Give Mr. Fredricks #91 a shout and a big kiss for for me! ;D

Rob is your boy freind?! Run for the hills girl!  :o ;D ;)

[tcchin]

HP is work,
              Torque is force.
              
              The answer to WHY
              is why not
              
              
              
              Now everyone lets define Irony

The only irony here is that HP is power := d(work)/dt, torque is work and work is the cross-product of the force vector and the distance vector. Get it right.

Few people experience "HP".  Maybe at Daytona.  But torque you can feel.  Do you guys recognize the difference?  I don't teach schools with equations.  It has no feel.

And Dave, I still don't see your point about feeling torque and not feeling power. They are inseparable, so if you're feeling one, you're feeling both. Sorry, but I went to school to get a feeling for equations. Knowing which equations are governing my environment helps me to better understand my environment.

[Baltobuell]

All I know is my Buell has tons of torque and I can get off the line faster than most anybody, once rolling most anybody is faster. ;D

[Woofentino Pugrossi]

Wheres that confused smilie? :-/ ;D