Ok, so everybody and their grandma argues torque vs horsepower. The thing is, not everyone knows what the difference is. I'm going to explain it in a way that everyone can understand, and so there will never be an arguement about it again.
The basics. Torque is leverage. Horsepower is how is often you make torque.
Torque is work, horsepower is power. Torque is measured in pound-feet. It differs from foot-pounds, because one pound-foot, is equal to 6.28ft/lbs. Like I said, torque is leverage. Imagine you want to move a rock, but can't do it yourself. You use a 5' stick wedged under the rock. Now, when you pull down on that stick, the weight of your body times 5, is the amount of torque you apply. BUT, it has NOTHING to do with how QUICKLY you pulled down on that stick.
Lets say you and a friend are both in a wheel chair. You both weigh the same, except your friend is a slob who's never seen a gym, and you're pretty fit. Lets say the wheel chair wheels are 2' in diamter. When both of your grab the rim and push, you're both capable of exerting 50 lbs of force. Because of the 1' radius wheel, you're both making 50lb/ft of torque. Because of your limited arm span, you were each able to turn the wheel, 1/4 turn. Because you're a bit more fit, you were able to make that 1/4 turn, twice as fast. You my friend, are twice as powerful. You both produced the same amount of torque, and were both CAPABLE of moving your wheelchairs, but you were able to do it faster. You had more POWER. My point? Power accelerates you faster.
Lets say you were going to race some 500lb, 50 year old lady. She, somehow, is JUST able to turn the wheels and get herself moving. You both produce enough torque to move the weight of your bodies. This time, you are able to turn your wheel 4 times, in the time it takes the lady to turn hers once. You are 4 times as powerful, and will move 4 times as fast. Why? Because you're making your torque more often.
Now, what does this have to do with cars? Almost every car makes enough torque to get it moving quite easily. If you can spin the tires, you're making enough torque. Torque dictates HOW MUCH weight can be moved. Horsepower dictates HOW FAST you can move it.
When you make torque, you're automatically making horsepower. Increase torque, and horsepower automatically goes up. This is because horsepower is equal to RPM times torque, divided by 5252. If you make 100lb/ft of torque at 3000RPM, that's equal to 57 horsepower. Increase your torque to 200lb/ft at 3000RPM, that's equal to, you guessed it, exactly double at 114hp. And your car would accelerate a significant amount more with twice the power, AND you could carry a significant more weight while doing it.
OR, what's just as good as making twice the torque to make twice the horsepower? Yep, make it twice as fast. Making 100lb/ft at 6000RPM, is just as good as making 200lb/ft at 3000RPM.
The only way to make torque, is to increase engine size, or increase volumetric efficiency. Which means if you're limited to engine size, you either have to slap on a turbo, or massage the hell out of the engine. Obviously raising compression ratio helps, but not much.
With a turbo, you increase horsepower, by increasing torque. RPM does not matter. With an NA application, you increase high RPM efficiency to increase horsepower. The more often you make torque, the more power you make.
So if you're 'building for torque', you're making the most torque you can. You want to make horsepower by making gobs of torque. Sure, you can spin the tires in any gear at 3000RPM, but it's killer on the drivetrain.
Or you can build for horsepower and massage your engine to effecient at 8000RPM. So that measly 125lb/ft, still makes 190hp at 8000RPM. And WILL accelerate you just as fast as a car with 333lb/ft of torque and 190hp at 3000RPM.
The basics. Torque is leverage. Horsepower is how is often you make torque.
Torque is work, horsepower is power. Torque is measured in pound-feet. It differs from foot-pounds, because one pound-foot, is equal to 6.28ft/lbs. Like I said, torque is leverage. Imagine you want to move a rock, but can't do it yourself. You use a 5' stick wedged under the rock. Now, when you pull down on that stick, the weight of your body times 5, is the amount of torque you apply. BUT, it has NOTHING to do with how QUICKLY you pulled down on that stick.
Lets say you and a friend are both in a wheel chair. You both weigh the same, except your friend is a slob who's never seen a gym, and you're pretty fit. Lets say the wheel chair wheels are 2' in diamter. When both of your grab the rim and push, you're both capable of exerting 50 lbs of force. Because of the 1' radius wheel, you're both making 50lb/ft of torque. Because of your limited arm span, you were each able to turn the wheel, 1/4 turn. Because you're a bit more fit, you were able to make that 1/4 turn, twice as fast. You my friend, are twice as powerful. You both produced the same amount of torque, and were both CAPABLE of moving your wheelchairs, but you were able to do it faster. You had more POWER. My point? Power accelerates you faster.
Lets say you were going to race some 500lb, 50 year old lady. She, somehow, is JUST able to turn the wheels and get herself moving. You both produce enough torque to move the weight of your bodies. This time, you are able to turn your wheel 4 times, in the time it takes the lady to turn hers once. You are 4 times as powerful, and will move 4 times as fast. Why? Because you're making your torque more often.
Now, what does this have to do with cars? Almost every car makes enough torque to get it moving quite easily. If you can spin the tires, you're making enough torque. Torque dictates HOW MUCH weight can be moved. Horsepower dictates HOW FAST you can move it.
When you make torque, you're automatically making horsepower. Increase torque, and horsepower automatically goes up. This is because horsepower is equal to RPM times torque, divided by 5252. If you make 100lb/ft of torque at 3000RPM, that's equal to 57 horsepower. Increase your torque to 200lb/ft at 3000RPM, that's equal to, you guessed it, exactly double at 114hp. And your car would accelerate a significant amount more with twice the power, AND you could carry a significant more weight while doing it.
OR, what's just as good as making twice the torque to make twice the horsepower? Yep, make it twice as fast. Making 100lb/ft at 6000RPM, is just as good as making 200lb/ft at 3000RPM.
The only way to make torque, is to increase engine size, or increase volumetric efficiency. Which means if you're limited to engine size, you either have to slap on a turbo, or massage the hell out of the engine. Obviously raising compression ratio helps, but not much.
With a turbo, you increase horsepower, by increasing torque. RPM does not matter. With an NA application, you increase high RPM efficiency to increase horsepower. The more often you make torque, the more power you make.
So if you're 'building for torque', you're making the most torque you can. You want to make horsepower by making gobs of torque. Sure, you can spin the tires in any gear at 3000RPM, but it's killer on the drivetrain.
Or you can build for horsepower and massage your engine to effecient at 8000RPM. So that measly 125lb/ft, still makes 190hp at 8000RPM. And WILL accelerate you just as fast as a car with 333lb/ft of torque and 190hp at 3000RPM.
