BHP is simply a measurement of torque at any given RPM.
Engines don't produce 'horsepower' as a force, they only produce turning force (torque). Horsepower is a measurement of this torque, the more torque an engine produces at any given RPM, the higher the BHP will be. That's why Honda engines have high BHP for the torque output, because it holds it's relatively low torque output all the way up the rev range.
Horsepower = torque x rpm / 5252
For example: 200 ft/lb at 4000rpm is 152.3 bhp, but 200 ft/lb at 6000rpm is 228.4 bhp.
couldn't have worded it better myself very good simple explanation.