HP as a function of RPM, torque

["Warren R Anderson" <wranderson@xxxx>]

>I am unfamiliar with how peak horsepower is calculated or whether it has
>anything to do with peak torque

An engine on a dynamometer, rotational horsepower is calculated from torque
and RPM numbers. Torque can be measured and RPM can be measured; horsepower
is a calculated number. HP = Torque x RPM / 5252(units conversion factor
where Torque is in lbs-ft).

An internal combustion engine is not a constant or linear torque or a
constant or linear HP machine. Horsepower available (calculated from torque
and RPM) will be a variable and will reach a maximum (peak) at some RPM.
Measured torque will likewise reach some maximum peak but at some other RPM.
They will not peak at the same RPM.

Given dyno torque and RPM numbers, peak torque at some RPM can be
determined. From calculated HP figures, peak HP is determined. Computers do
all this of course as you see on TV when the Horsepower TV guys run a car on
their DynoJet (sp ?) inertia chassis dyno.

Etc., etc. HTH

Warren Anderson
Sedona.AZ