What is HP anyway?

[rocco16v at netzero.net (L F)]

Horsepower (HP) is calculated from the torque (and rpm) that an engine produces on an engine brake aka dynomometer.  It is a very standard calculation.  Horsepower is not measured, it is calculated.
It can be determined from torque values taken/measured at the crank (engine dyno) or at the drive wheels (chassis dyno).

Torque, and therefore horsepower, can ONLY be determined by using a dyno.  Anything else is a guess.

Larry
  HP = calculated horse of engine based on torque @ rpm. there doesnt seem to
  be a set standard of measurement for this one.

  BHP = brake horsepower, measured at the output of the crank. 'brake' comes
  from the method of measurement. engine is run wide open, at a specified rpm,
  with some form of braking mechanism loading down the crank to keep it at
  that rpm constantly. the amount of torque on the brake factored with rpm
  gives BHP. this is the most accurate way to measure engine output, but its
  not very practical since you need an engine dyno.