Accelerating using torque or hp?

[topau]

On the other part of forum there was an out of topic discussion about what is needed to accelerate. This was just too tempting to leave this out. And yes I know that I am throwing some 98E5 to flames. ;-)

I was trying to correct a common misunderstanding by saying that it is torque what you need to accelerate a car, not power. Actually torque to front wheels is defining the acceleration.

Couple of references trying to explain this...
http://www.allpar.com/eek/hp-vs-torque.html

http://www.houseofthud.com/cartech/torqueversushorsepower.htm

Quote from later link:
Horsepower, Torque and how you use it to accelerate through gearing

So what's the whole deal with the "torque curve" and why's it important to acceleration?
Well.. only being able to make good torque at a single rpm is not very useful for a road going vehicle.

It's ok for a train engine driving a generator, or factory motor, but no sense for a car. If you
only make useful torque at the crank in a very narrow range of rpms then you need lots and
lots of gears to keep the torque at the wheels in a useable range as your vehicle's speed
increases. Maximum acceleration of a car is made possible by maximizing your output
torque at the wheels at ALL times.

Any comments?

 

[l_jonez]

Yep had this argument a few times, it's all about torque. As it says above max torque is over a narrow band, anyone who drives a diesel knows its .... No power, no power, no power, no power, no power, POWER, change gear