fiestaturbo.com

[Fez Si Boy]

Can anyone explain torque fully? does it mean pulling power of engine?

[Stoned]

It would be easier to read about it here from a Pro

http://www.pumaracing.co.uk/power1.htm

Quality site btw. Well worth a read.

[Phil Si]

Al did an explanation in laimans terms

My understanding of this is not great but here's a quote from Ride magazine:

"Power and Torque - what's the difference?

Torque
Torque is what moves your bike. When you're doing 50mph, it's torque that lets you do it. Torque is simply a turning force. When you open a jam jar you use force to rotate the lid. You are applying torque on the lid.
In an engine, petrol and air burn in the cylider. As they do, heat expands the gas. The only thing that can move in the cylinder is the piston, so the expanding mixture forces it down. This force is not yet torque but the piston is connected to the crankshaft, and all that can do is turn. The force acting on the piston acts on the crankshaft and produces torque by turning it. The amount of torque produced depends on two things; the force applied to the piston and the length of the lever (i.e. half the engine's stroke - half a revolution). To increase the force, we use the throttle. By opening it, we let more air and fuel into the cylinder, which expands more when burnt, and pushes down harder. Therefore you get more torque.

Power
Power is how quickly something can do work. If you and a mate who weighed the same raced up a flight of stairs you would both be doing the same amount of work (because you'd be raising your bodies by the same vertical distance). However, if you reached the top in half the time they did [or vice versa for your flabby ass Craig ], then you must be twice as powerful - as you've done the same amount of work in half the time. So an engine with twice the power can do the same work [same torque] in half the time [double bhp - i.e. a motorbike engine which can rev to 10,000 rpm produces 100bhp at 10,000rpm but peaks at only 50Nm torque at 5,000rpm, just for example, compared to an engine which produces peak power at 5,000rpm of 50bhp and peak torque of 50Nm, just for example].
The amount of work an engine can do is down to its torque (power = torque x revs}. Think of torque as the ability to climb stairs. An engine with 50ft lb torque might be able to take one step at a time, but another that has 100ft lb could take two steps at once. Power (bhp) takes into account time; if the first engine had twice the power of the second engine (meaning it could also take two steps at once, but at double the revs) they'd be climbing at the same speed."

So torque is how hard the engine pushes, whereas power is how quickly it can turn the crank while pushing that hard.

Additionally, how well a car can lay the power down through the use of electronic traction control and LSD gearing, the management systems, etc, all make a significant difference but the main issue is engine efficiency and hence power output which results in torque and BHP figures.

Finally, you can also think of it like this: when you're accelerating, peak torque is when you're being pushed back into your seat the hardest because the acceleration of the car's acceleration is at it's peak, whereas at peak power you're no longer being pushed into your seat as hard but your acceleration is greatest (but the accleration rate is neither increasing nor decreasing).

... a confused and tired Al.

[SimonT]

so basically:

Torque is what moves your car

and BHP is how quickly it does it

[Phil Si]

i suppose in a way it could be to electricity... the amps are the power and volts are the things that shove it around lol

[memoorhouse]

Bingo! you got it

[df908]

when you're accelerating, peak torque is when you're being pushed back into your seat the hardest because the acceleration of the car's acceleration is at it's peak, whereas at peak power you're no longer being pushed into your seat as hard but your acceleration is greatest (but the accleration rate is neither increasing nor decreasing).

One derivative too far there, what you mean is "acceleration of the car"...

...not "acceleration of the car's acceleration", thats at the point at which torque is increasing most rapidly, not where it peaks...

Peak torque is the point where dv2/dt (ie acceleration) is maximal). Force = mass x acceleration, innit?

<spod hat off >