HP or Torque

[kovachian]

Picking one or the other is impossible for me, it's all in the relationship between the two. You can't have the Yin without the Yang.

[SDNR]

Great topic guys.

I wonder if somebody here would like to try and explain precisely what torque is?

[Matt]

Good question. I always thought of torque being proportional with high displacement. This may be completely wrong but i thought of it as the punch, for lack of better word, behind the piston as it goes up and down. Martin can explain it.

[Centurion]

Originally Posted by Roberto

Great topic guys.

I wonder if somebody here would like to try and explain precisely what torque is?

I can't really explain torque scientifically but I have always thought of torque as the strenght of making a car move(accelerate). Most vans have diesel engines since they often are troque monsters. For trucks and lorries torque is important so that the lorry can pull up the whole load even if it starts upphill. Driving a car with lots of torque you usually don't have to do anything more than press the throttle slighty to make the car take off instantly.
Bentley Arnage T Mullier has an engine which produces over 800nm meters of torque so that the driver can without effort make the enormous weight of the car start moving.
Torque is often only beneficial from 0-100km/h hour. At higher speeds horse power is what's going to make the car fly. A good example is the 911TT which produces 620nm. That is what enables the car to be so damn quick from 0-100km/h compared with the Gallardo which has an engine producing 510Nm. Due to the Gallardo's engine developing more horsepower than the Porsche, the 911 loses at high speeds especially over 150km/h

[Snake Vargas]

Torque is force, basically.

If you have a (mass-less) two-metre lever with a 1kg object resting on each end and the fulcrum in the middle, the force exerted by the objects would be 1 newton metre each, balancing out.

However, torque is twisting force. If that lever is only 1 metre, fixed to a stationary pivot, with one 1kg object on the end, then it exerts a 1Nm force on the pivot.

What all this has to do with things isn't clear, but from my hazy recollection of high school physics and engineering science, that's about it.

Toqrue is often a function of high displacement, and of high compression as well, I think. So a high compression ratio engine makes more torque, a large engine makes more torque, and forced induction increases the effective displacement so it also produces a lot of torque.

Anyhow, again, torque and power aren't separate entities that you can have less of one or more of another as you choose. Power = Torque x Engine Revs, using the correct units of measurement to make sense of the results. High revs means higher power. High torque at high revs means higher power. Power is the rate of energy output.

In a way, power is more important than torque. On the other hand, from the above equation, power is nothing without torque, to put a spin on an oft-coined saying.

More important is the way you want to drive. If you want to rev out the engine every time to make for good accleration, then that's a good way. That makes for poor fuel consumption, however. Torque at low revs is good for hauling goods and general driveability. Power is good for racing because they don't really mind what amount of fuel they use, the noise made or the lack of comfort in the driving style.

The curve under the power graph is important for acceleration, in combination with the gearbox and judicious selection of gear ratios.

Well, I'm not sure if anything is made clearer, again, but hey, main point - you can't really say that one is more important than the other without further clarification.