Engine Performance: torque vs. HP

[black330i]

Can anyone out there explain why an engine's max torque and max horsepower don't occur at the same RPM?

Also, what makes an engine more "torquey"? I saw a Hummer H1 the other day and I learned that although it only has 194 HP, it has over 400 lb-ft or torque. I guess I should have studied mechanical rather than electrical engineering

Thanks

 

[Wadula]

i always compare torque with the strength of a weightlifter. this guy has lots of power but only at a a certain speed. or to put it another way, if he tries to lift a weight faster than usually, he might not make it. now, at his optimum speed, he can lift a tree. hp is just the mathematical result of torque times rev, i.e. how many times he can lift the tree in a minute.

no, i did not study kids psychology, it´s just my fantasy that comes up with those weird ideas

 

[MrElussive]

Checkout this site, it is very informative:
http://www.vettenet.org/torquehp.html

I could explain it myself, but I do not want to be factually incorrect.

The H1 has lots of torque because it is a diesel engine...low horsepower, so it's not quick at all, but lots of torque, so it can haul a lot of weight (i.e. tow a lot).

 

[Wadula]

forget the darn weightlifter

 

[Dinan55]

I'm copying this straight out of the book.

"Engine brake horsepower increases with engine speed. Engine torque increases with engine speed up to the point where the engine is drawing in the maximum amount of fuel mixture, after all factors are considered. Torque is greatest at this point, and any additional increase in rpm will cause torque to dominish."

 

[Average Jae]

forget the darn weightlifter

good try ^^;;

 

[Militant-Grunt]

Im sooooooo confused.