tq vs. hp
#11
#12
The simplest way to describe torque is as a twisting force. Basically, if you've got a lot of torque, you can rotate a shaft all day long at a given rpm even if the resistance or load increases.
Power=torque x angular speed
So if you've got a lot of torque and you can apply it at a high rpm, this is where power comes in to play. Vehicles that have a huge top speed (like a race car or even a passenger jet plane) have a ton of top end power at very high rpm, and relatively little torque. Vehicles that can pull a huge amount of weight and have a low top speed normally also possess a huge amount of low end torque, like a freight train or semi-truck and comparatively less peak power.
Power=torque x angular speed
So if you've got a lot of torque and you can apply it at a high rpm, this is where power comes in to play. Vehicles that have a huge top speed (like a race car or even a passenger jet plane) have a ton of top end power at very high rpm, and relatively little torque. Vehicles that can pull a huge amount of weight and have a low top speed normally also possess a huge amount of low end torque, like a freight train or semi-truck and comparatively less peak power.
#14
#16
Torque is what you feel when your rig sets you back in the seat.....torque is what does the work.
Horsepower is a measurement of work capable of being performed in a certain amount of time. The mathematical calculation, as said before of HP = TQ x RPM / 5252 is used to derive a horsepower figure.
Torque gets you moving....horsepower keeps you moving. Horsepower sells parts....torque wins races. One could go on and on with this. It's true, to a point.
Horsepower truly is only a number derived from a mathematical equation, and does not mean an engine is "powerful" in a pure sense, only that is capable of doing X amount of work in Y amount of time...
Engine parts and changes to an engine do not build horsepower directly...they build torque, and the ability to increase usable RPM, which in turn builds the horsepower figure.
A 600hp CAT C-16 diesel engine makes an extreme amount of torque at a relatively low RPM, therefore the horsepower number is much lower than one would see out of a 900hp McLaren Formula 1 engine, turning to 18,000+ RPM but making a relatively low amount of torque.
So really, an engine is making a force of energy...in this case a twisting force...torque. How much torque x how fast it spins while doing it = horsepower.
That's all there really is to it.
**EDIT**
Another tidbit to chew on...
At 5,252 RPM, the calculated horsepower number will equal the true torque number, and every RPM above that will show a larger horsepower number than torque. Nothing more than the result of the constant in the equation. So when you see torque numbers higher than horsepower, and vice versa, that is only due to the RPM used to come up with the horsepower figure.
An engine will NEVER have more torque than horsepower above 5,252 RPM. It is mathematically impossible.
Horsepower is a measurement of work capable of being performed in a certain amount of time. The mathematical calculation, as said before of HP = TQ x RPM / 5252 is used to derive a horsepower figure.
Torque gets you moving....horsepower keeps you moving. Horsepower sells parts....torque wins races. One could go on and on with this. It's true, to a point.
Horsepower truly is only a number derived from a mathematical equation, and does not mean an engine is "powerful" in a pure sense, only that is capable of doing X amount of work in Y amount of time...
Engine parts and changes to an engine do not build horsepower directly...they build torque, and the ability to increase usable RPM, which in turn builds the horsepower figure.
A 600hp CAT C-16 diesel engine makes an extreme amount of torque at a relatively low RPM, therefore the horsepower number is much lower than one would see out of a 900hp McLaren Formula 1 engine, turning to 18,000+ RPM but making a relatively low amount of torque.
So really, an engine is making a force of energy...in this case a twisting force...torque. How much torque x how fast it spins while doing it = horsepower.
That's all there really is to it.
**EDIT**
Another tidbit to chew on...
At 5,252 RPM, the calculated horsepower number will equal the true torque number, and every RPM above that will show a larger horsepower number than torque. Nothing more than the result of the constant in the equation. So when you see torque numbers higher than horsepower, and vice versa, that is only due to the RPM used to come up with the horsepower figure.
An engine will NEVER have more torque than horsepower above 5,252 RPM. It is mathematically impossible.
Last edited by Mr. Miyagi; 07-26-2009 at 03:00 AM.
#17
to get good torque numbers you have to get the charger lit very early or as others have said good air flow down low, for horsepower you need air flow up top. its all about when you get the air for example my s465 doesnt light till 2000 rpm which is why my torque number is low ... but I have the air flow up top so my horsepower number is high. This is why twins are very popular good air flow down low with top end flow. a properly sized single is also a great choice