put it this way. In a 1/4 Mile.... HP is Speed, Tourqe is Time.... to an extent.

 

Not the first time I have heard that, and I do agree with that thinking. I remember when I was much younger (maybe 8 or 10) wondering and asking why some guys could win races consistantly with lower top speeds, and the explanation was very similar to what you posted, and oddly I still remember it [img]i/expressions/face-icon-small-smile.gif[/img]

 

Torque is how much work you can do
Horsepower is how fast you can get it done

 

at what rpm does it assign that hp? same as torque?

 

HP is the same as torque when rpm is 5252. HP is the same as RPM when torque is 5252. Altough this is an interesting view of the equation. The fact is, HP is simply the product of torque and rpm. If the power is w, torque is in Nm and speed is radians per second, there is no 5252.
Power (w) = Torque (Nm) * Speed (rads/s)

In this case, when the speed is 1 radian per second (9.5 rpm), Torque and Power are the same!!

 

That's right. for example.......

My old 70 chevelle drag car ran a 377 small block chevy. We ran a 1000ft track, right between 1/8 and 1/4. With the original combo the car had 1.44-1.45 60ft times and ran 8.6's and 8.7's at around 113-114mph and that was shifting at around 6800rpms. Now when I tore the motor down I changed cams and went to a higher duration and lift. The car still ran consistent 8.6's, but things were reverse at the start and end. The 60ft times came up to around a 1.47-1.48, but the trap speed increased to 116-117mph and shifting occured at around 7000-7200rpms. The first motor combo made more torque in the middle and would holeshot hard, but the second combo made more HP on top end which resulted in a higher trap speed. Overall more torque especially lower on the rpm range makes for a lot more fun driving or riding.

 

The reason this happens is that you cannot keep the engine at its peak HP throughout the run. Now if you have something like a CVT transmission, you can make use of the peak HP and your ETs would be lower. This is one reason snowmoble engines that put out such high horsepower and are so high strung accelerate so quickly.

 

This is a really good way to think of it: (from HughJazz)

"Torque is how much work you can do -
Horsepower is how fast you can get it done "

Torque is force, like foot-pounds.... think strength.
HP is that force over time, how "fast" you can deliver that force to the wheels or ground, where ever you chose to measure it.

Each different racing application will need the particular optimum combination of these two, it's not always the same answer. Torque might be more important to trail riders, and HP might be more important to drag racers.

 

of course as we all know torque equals the force required to get an object moving, horsepower equals the amount of force required to move an obect over a cetain distance, simple?

 

Almost, but HP is dependent on the time taken while the force is applied. The lower the time, the higher the HP. The time comes in RPM or rev/min.
BryceGTX