here i found few info on BHP and torque from link BHP and Torque Explained - The Biketuna Wiki
. Now what can we do about pridor with this info
hat is BHP? What is Torque? What do they mean and how do they relate to eachother?
BHP and HP
All the B means is "brake". The old word for a dyno - because the engine torque was measured by applying a brake to the flywheel rather than a torque converter or electrical motor which is how it's done nowadays. There's no other difference between the two and they both just mean horsepower.
HOW TORQUE AND POWER RELATE
The final part of the story is to see how we calculate power from torque or vice versa. Let's imagine we have a pulley at the top of a mine that is 1 foot in radius - or 2 feet in diameter. At the bottom of the mine, at the end of a rope leading round the pulley is a bag of coal weighing 100 pounds. Instead of using a horse to pull on the rope let's connect an engine to the pulley - perhaps by bolting the pulley to the crankshaft of the engine.
In order to lift the coal we need to apply a torque of 100 foot pounds to the pulley because the coal is pulling down with a force of 100 pounds applied at 1 foot from the axis of rotation. In other words the Torque applied is the Weight times the Radius of the pulley. If the engine turns the pulley at 1 revolution per minute how much work is being done?
Well for each turn of the pulley the coal will rise the same amount as the circumference of the pulley which is 2 pi times the radius = 3.14 x 2 = 6.28 feet. So in 1 minute the engine will do 628 foot pounds of work. Copyright David Baker and Puma Race Engines
We can rearrange the above in terms of torque and speed:
The rate of work being done (or Power) is Force x Distance per minute = Weight x radius x 2 pi x rpm foot pounds per minute. However we already know that Weight times Radius = Torque so we can equally say:
Power = Torque x 2 pi x rpm
To turn this into Horsepower we need to divide by 33,000. Our final equation therefore becomes:
Horsepower = Torque x 2 pi x rpm / 33000 which simplifies to:
Horsepower = Torque x rpm / 5252.
This is the universal equation that links torque and horsepower. It doesn't matter whether we are talking about petrol engines, diesel engines or steam engines. If we know the rpm and the torque we can calculate horsepower. If we know horsepower and rpm we can calculate torque by rearranging the equation above:
Torque = Horsepower x 5252 / rpm
Hopefully you can also see that when an engine is turning at 5252 rpm, its torque and horsepower figure is the same. Next time you see a graph of the torque and horsepower of an engine check to see that the lines cross at 5252 rpm. If not then the graph is wrong. This only applies of course if the power is being measured in horsepower and the torque in foot pounds and both lines are shown on the same axes. There are many other units in which torque and horsepower can be measured - for example power can be measured in Watts and torque in Newton metres. Unless we need to convert to such continental measures we can usually stick to horsepower and foot pounds.
One measure to be aware of though is the "continental horsepower" or PS. This stands for "PferdeStarke" - the German translation of "horse power". In France you sometimes see the same measure being called a "CV" for Cheval Vapeur. This measure was chosen in Europe as being the closest thing to a horsepower that could be expressed in nice round metric units - 75 kilogramme metres per second to be exact. It is commonly used by car manufacturers nowadays and tends to get used synonymously with bhp although it is actually a slightly smaller unit of power. One PS is about 98.6% of one bhp. The conversion table below covers the units most commonly used to express power and torque.
To convert:
BHP to PS: multiply by 1.01387 BHP to Ft Lbs/second: multiply by 550 BHP to Watts:multiply by: 745.7 PS to Kg M/second: multiply by 75 PS to Ft Lbs/second: multiply by 542.476 PS to Watts: multiply by 735.5 Kilowatts to BHP: multiply by 1.341 Kilowatts to PS: multiply by 1.360 Lb-Ft to Nm: multiply by 1.356
