How to explain Torque ?

I think he needs a good thrashing for starting this thread .


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Originally Posted by sdusk

..blah blah...just believe the marketing hype..blah blah .. relates to a general misunderstanding coupled with marketing brainwashing....

Blimey! What's it to do with Marketers? Engineers invented all this stuff so they could see if their ideas were better than the next guy's! It was all to do with testosterone and how big their slide rules were....

Engineers...pah....spawn of the devil......invented some of the worst stuff in the world....

Originally Posted by nickj

Dotted........be honest, are you even more confused now

hehehe , true

Originally Posted by jonboy

I think he needs a good thrashing for starting this thread :Laughing: .

opps , i do .... didn't even bother to use the search button , before i post


But I'm learning a lot , its all about basic high-school physics , and understanding the difference between the concepts of Force and power , and add rpm to them!

After reading stuartboy post , i think it finally clicked , rpm(time) was the key factor that i wasn't taking into account when trying to figure out the difference between power and torque !
One engine turn results into a force(torque) , the faster the engine turns(rpm) the more force per minute it produces(power).

But that makes power curves and torque curves the same thing in a different package
Its the shape of the curve that tells you what a bike fells like !

ps: yes i know , you guys are telling the same thing for 3 pages...



Edit: So... since F=mA , more torque(F) = more Accel (A) ?

Originally Posted by sdusk

Stuartyboy, I take it you are not being serious. (I sure am - I don't think the laws have been rewritten just yet ) If I didn't feel the change in speed (acceleration) then I probably wouldn't be interested in cars or bikes at all! ( Sorry but you cannot feel acceleration. If you could feel acceleration then you could also feel speed and time- see formula below - me I feel the need for speed ) When a car pushes you back in your seat or your bike pulls on your wrists what is it doing? I do believe it is accelerating. Yes, but the "accelleration" isn't pushing you or pulling you - its the torque When it is pushing you back the most I think you would agree that it is accelerating the most. When these forces( That would be the torque force then ) are experienced in your car/bike can be easily matched to the power chart. They do not relate to the torque curve. it does relate - its a fundamental component of the curve Last time I checked I don't have a built in torque sensor Yes you do - your inner ear is one of your most important torque sensors

The only way to prove you cannot feel acceleration is mathematically...

Acceleration is measured in Meters per second per second. You can't feel a metre and you can't feel a second.

acceleration = Velocity(2) - Velocity(1)
-----------------------------
Time


acceleration = 5m/s - 0m/s
---------------
5s

acceleration = 1m/s
-----------
1s

Or 1 metre per second per second - which is a number (you can't feel numbers).

Now Torque is a Force.

and

Force= Mass x Acceleration (You can feel mass)

Point proven.

I'm off to the pub now.

Originally Posted by dotted

After reading stuartboy post , i think it finally clicked

Shamone

Check this link - it has animations on engines and stuff and explains it quite well.

http://science.howstuffworks.com/fpte4.htm

I've recently spent time trying to define tourque, and its differance from power:

As others have mentioned, tourque refers to a turning force i.e. how much force is applied to turning (right?)

Power is an energy measurment - the energy of the combustion of feul (chemical energy) turned into the kinetic energy (expansion of gas moving the pistons moving the various other mechanical parts and finally you).

Consider the SI units of power, given as watts (or kilowatts, makes nicer numbers!) which turns out to be J/s (joules per second) - i.e. the amount of energy (at a given RPM!) produced by the motorcycle per second.

So, in summary: Tourque is t do with turning, Power is to do with energy!

Matt

So, if my bike has a big number of HP (a lot of power) I will be able to hurtle along faster than I can cope with very quickly BUT I might have to change gear a lot (FZ6). If, on the other hand it has a big number of lb/ft (a lot of torque) I may or may not leave the lights like greased weasel **** but I will spend less time working the gear shift (SV650).

Me? I'm bone idle and ride like your granny so I want torque not power, therefore

Torque = good. QED.

Tiger

PS - NOT to suggest for a second that any other SV owner is a lazy pootler, that's just me...

Horsepower is the power.
Torque is the strength of the power.

Does this help?

stuartyboy (I didn't want to quote your whole post, so apologies).

I tend to disagree. You can feel the effect of acelleration. Acceleration is defined as a finite change of speed, in a finite time, as you said. Speed, is worked out based on mass, and energy. Time, granted, cannot be felt. Edit: but still we know it passes by...movement of sun being the prime reason.</edit>

Acceleration happens when you increase the amount of fuel flowing to the combustion chambers in the engine, this has the effect of making the pistons move quicker, which eventually, increases the torque applied at the rear wheel. Apply a constant torque, and you get a constant speed. Therefore acceleration is caused by a change in torque (as is decceleration - engine braking).

On this principal alone, forgetting about increased drag to the rider, acceleration happens because of a change in force. That's something you can feel.

I do agree however, that when you twist your wrist, you can't feel that you are accelerating at (eg) 5m/s/s. But you certainly know you are accelerating.

I still stand by torque = turning force, HP = pulling force (eg, as a horse used to pull a steam engine/boat using a roap).

Edit in hindsight: Using the maths, a=(v2-v1)/t ... the ONLY thing changing in the entire system (mathematically) is the force applied, and this causes acceleration. You feel the change in force. But the explaination can stay

Excellent thread, I now feel I could pass a physics a level!

This all still boils down to what you personally prefer, not which number is more relevant. I just like being dragged around at low revs with a nice thuddy engine, so I am looking for high torque at low revs