RE: Good Question about Horsepower

[Don Muirhead <dmr@kwic.com>]

Stephen:

Hate to disagree with another canajun, but you measure HP/torque using a 
dynamometer using various rpm's to measure the load of your engine starting 
with a guesstimate of the red-line of say 7-8,000 and reduce by 500 rpm's 
thereafter making notes of hp and torque at each level.   What you end up 
with is a hp and torque curve.  In all engines there is a peak in hp/rpm 
followed by a gradual loss - ditto for torque.  Where the hp/torque 
intersect is generally considered your torque rating and he peak hp point 
on your graph your hp.  If you try to measure this at full throttle chances 
are you will exceed the peak hp and torque output and before you know it 
you will have incurred engine stress and a permanent loss of hp/torque or 
worse a lot clunking and clattering sounds.  Btw - don't forget to weigh 
car.

Don Muirhead
Simcoe, ON