Why does horsepower and torque Cross at 5252 rpm?
It all boils down to the math behind both horsepower and torque. One horsepower is equal to 33,000 foot-pounds of work per minute. Add in the equations relating to torque and velocity, and you’ll find that horsepower always equals torque multiplied by rpm, divided by 5,252.
Why is torque divided 5252?
No constants like 5252 are present in it. The reason is that the units are included in physical quantities. In the SI system commonly used in physics, power is in Watts, torque is in Newton-metres, and angular speed is inverse seconds or radians per second. This means that 1 Watt= 1 Newton.
What is the constant 5252?
The number 5,252 is the result of lumping several different conversion factors together into one number. First, 1 horsepower is defined as 550 foot-pounds per second (read How Horsepower Works to find out how they got that number). The units of torque are pound-feet.
How is 5252 derived?
The constant “5,252” is derived from the fact that a circle 1 foot in diameter has a circumference of 6.2832 feet. Dividing 33,000 by 6.2832 results in 5,252 and resolves the units for the equation.
What is the relationship between horsepower and RPM?
Mathematically, horsepower equals torque multiplied by rpm. H = T x rpm/5252, where H is horsepower, T is pound-feet, rpm is how fast the engine is spinning, and 5252 is a constant that makes the units jibe. So, to make more power an engine needs to generate more torque, operate at higher rpm, or both.
What RPM do you think the torque and horsepower should cross?
If you look at a lot of dyno charts, you’ll notice that horsepower and torque always seem to cross around 5252 RPM. Seriously. Just search Google Images for dyno charts and you’ll be blown away by how often this is the case.
How do you convert hp to torque?
Add in the equations relating to torque and velocity, and you’ll find that horsepower always equals torque multiplied by rpm, divided by 5,252. Canceling out the equal variables, you wind up with horsepower equaling torque… at 5,252 rpm.
What is power and torque?
There, we’re going to learn about power, torque, and velocity. You see, power is equal to force times any velocity. Velocity is understood to be a given distance divided by the time needed to cover that distance. Finally, torque is the figure generated by a force multiplied over a given radius value.
How much horsepower does a horse need to lift 75 kg?
James Watt, a Scottish engineer who developed the concept of horsepower, figured out that one metric horsepower is needed to lift 75 kilograms by one meter in one second. It’s related to how much work a horse will do related to the same work done by a steam engine.