Torque vs. Horsepower
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From: rockaway
Torque vs. Horsepower
I was attempting to explain to someone what the difference between horsepower and torque is. The exact definitions, I admit, I'm kinda hazy on (if someone would like to enlighten me, it would be much appreciated 
) Anyway, the simplest way that I could put it so that this person would understand was that Torque = Acceleration and Horsepower = Speed. Am I correct in this assumption? or am I just a total dumbass? Thanks for the help. As Jonny of the Fantastic Four would say: "FLAME ON!!"
) Anyway, the simplest way that I could put it so that this person would understand was that Torque = Acceleration and Horsepower = Speed. Am I correct in this assumption? or am I just a total dumbass? Thanks for the help. As Jonny of the Fantastic Four would say: "FLAME ON!!"
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From: Granville OH
Actually, that's a really good question. Torque by definition is "force times distance". In other words, picture yourself putting 100 lbs. of force on a wrench handle that is one foot long. That is equal to 100 lb-ft. of torque. If you put 100 lbs. of force only 6 inches from the nut/bolt, then you're only applying 50 lb-ft. of torque (or as some say it, 50 ft-lbs. of torque).
Horsepower is a unit of power, which is the measurement of torque per unit time. To be specific, one horsepower equals 550 ft-lbs/second. It isn't an instantaneous measurement of "twisting force" on a shaft, but rather the amount of "twisting force" over time. That means that the speed at which the shaft rotates has significant impact over the amount of "power" delivered. If you have the same amount of torque at two speeds, one half of the other, then you are generating half as much horsepower with the slower speed.
That's why our engine has so much power. It has relatively low torque, but since the engine can rotate much faster in a given second, it can generate significantly more horsepower than an engine with similar displacement that has a lower redline.
Horsepower is a unit of power, which is the measurement of torque per unit time. To be specific, one horsepower equals 550 ft-lbs/second. It isn't an instantaneous measurement of "twisting force" on a shaft, but rather the amount of "twisting force" over time. That means that the speed at which the shaft rotates has significant impact over the amount of "power" delivered. If you have the same amount of torque at two speeds, one half of the other, then you are generating half as much horsepower with the slower speed.
That's why our engine has so much power. It has relatively low torque, but since the engine can rotate much faster in a given second, it can generate significantly more horsepower than an engine with similar displacement that has a lower redline.
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From: VA is for hustlaz
the reason the f20c makes so much power is that it can continue to build torque as the rpm raises, most cars cannot do this after 6k rpm. also, id rather have a engine with high hp at high rpm since i can take advantage of gearing.
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From: Calgary, AB
Just when you thought it was safe to rev to 9000.
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From: Ottawa
nownor,
Basically you are correct, but it is important to know why or else you'll get this "no torque" thing thrown at you as far as the S2000 is concerned. Without the full math and anally precise explaination...
1) Torque = acceleration (yes kind of):
Force (or torque) = Mass (actaully a rotation equivalent) * Acceleration (actually a rotation equivalent). So the car's acceleration is due to the torque...but the torque AT THE WHEELS, not the flywheel torque that all the magazines quote. So as RazorV3 mentioned, the gearing of the transmission, final drive gear ratio and wheel size have included when talking about acceleration. As you would expect an S2000 has relatively high gear ratios, compared to other sports cars, to give some good torque at the wheels. Another way to improve acceleration is to reduce mass.
2) HP = max. speed (yes kind of):
You reach max. speed when you stop accelerating. That happens when the force (torque) at the wheels is "cancelled" by the forces trying to stop the car. The biggest stopping force at high speed is wind resistence. HP = torque * (RPM/5250), so the more HP, the more torque can be supplied the particular RPM of the wheels. In other words max. speed is higher with higher HP (which also depends on how much wind resistence the car has).
Basically you are correct, but it is important to know why or else you'll get this "no torque" thing thrown at you as far as the S2000 is concerned. Without the full math and anally precise explaination...
1) Torque = acceleration (yes kind of):
Force (or torque) = Mass (actaully a rotation equivalent) * Acceleration (actually a rotation equivalent). So the car's acceleration is due to the torque...but the torque AT THE WHEELS, not the flywheel torque that all the magazines quote. So as RazorV3 mentioned, the gearing of the transmission, final drive gear ratio and wheel size have included when talking about acceleration. As you would expect an S2000 has relatively high gear ratios, compared to other sports cars, to give some good torque at the wheels. Another way to improve acceleration is to reduce mass.
2) HP = max. speed (yes kind of):
You reach max. speed when you stop accelerating. That happens when the force (torque) at the wheels is "cancelled" by the forces trying to stop the car. The biggest stopping force at high speed is wind resistence. HP = torque * (RPM/5250), so the more HP, the more torque can be supplied the particular RPM of the wheels. In other words max. speed is higher with higher HP (which also depends on how much wind resistence the car has).
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From: rockaway
thanks guys for the explanations..basically i was just getting at if my torque = acceleration and horsepower= speed idea was sorta right or totally wrong in order to use that simpleset of definitions to explain the two to someone who has no idea of anything. This had nothing to do with the whole "our car has no torque" blah blah blah issue...that i could care less about. Again, thanks for the explanations!!
