# Re: Torque curves and some confused pedantry

```> -- [ From: Huw Powell * EMC.Ver #3.1a ] --
>
> >> By the way, if you think of torque as the total area under the curve
>
> >if you think of *horsepower* as the total area under the *torque* curve?
>
> Well, which one is the integral or derivative of the other?  What are the
> units?  foot-pounds and foot-pounds/time?  In which case the torque could be
> derivative of the power and the second comment would be correct.
>
> But is the torque actually the derivative of the hp?  help, I've fallen and
> I can't get up!  No, it's not d(hp)/dt, it's just hp/t.  different plate o'
> cakes...
>
> especially considering I've substituted "t" for rpms.

Ignoring things like units... power is work/time, work is force times distance.
So, power = (force * distance ) / time
distance/time is velocity which is proportional to rpm (assuming no gear
changes now)
force is proportional to torque (depends on gearing)

So, out of this mess, we get:

power is proportional to torque * rpm

BTW: the G-Tech calculates hp from m*v*a.  It measures a (acceleration)
from its sensor, you enter m (mass of car) and it calculates v (velocity)
by integrating a over time.

Orin.

```