View Poll Results: HP -> Acceleration... not Torque!
Voters: 203. You may not vote on this poll
HP -> Acceleration... not Torque!
Registered User
Joined: Jan 2002
Posts: 250
Likes: 0
From: Redford, MI
Originally posted by KnightRider
OK, I think you do understand. But being on a car forum I think that when we talk about acceleration we are talk about things like a 1/4 mile time. That is acceleration over time. Force over time if you will. Torque over time to be more specific. And that is exactly what horsepower is. They are interrelated. You can go in circles forever between force and power, but I think it's pretty clear that power is much more relevant to cars.
OK, I think you do understand. But being on a car forum I think that when we talk about acceleration we are talk about things like a 1/4 mile time. That is acceleration over time. Force over time if you will. Torque over time to be more specific. And that is exactly what horsepower is. They are interrelated. You can go in circles forever between force and power, but I think it's pretty clear that power is much more relevant to cars.
Registered User
Joined: Jun 2001
Posts: 1,610
Likes: 0
From: Atlanta, GA
I have to say again that this is a great thread. I am very impressed by the depth of knowledge some of my fellow S2000 owners have on so many subjects. Just one more reason to be proud of the car I own...to be in such good company.
I am also impressed that this tread has managed to go on for 5 pages arguing over semantics. Horsepower vs. Torque is like asking what causes an eleictric motor to turn...voltage or watts? First, you can't have one without the other and second, voltage is a force and watts is power. There is a "step" of calculations missing in between them. Keeping with the electricity theme, it would be like a power company charging for the torque of their generators instead of power in Watts.
Which brings me to my point. Torque is a force and Horsepower is...well power. A force (torque in our case) does nothing unless applied over some vector. This can be measured in either distance or RPM's. Once a force is applied over said distance it does Work. This is described as Power and in our case written in the unit of HP. Think of it another way, wheel horsepower can be calculated 2 ways. First, by directly measuring the force the rear wheels applies to the ground over an RPM range on a dyno. Second, by calculating power from the the force needed to accelerate a car of a given mass from velocity A to velocity B over a given distance.
So, in conclustion, the answer is both. Torque is the physical force applied to the road by the rear wheels and Horsepower describes the amount of work done by that torque over a distance.
This probably does nothing to add to this thread, but I figured aince everyone was saying the same thing and different ways...I may as well, too.
Keep it up everyone. It is great to see that the art of a polite debate is not completely dead.
I am also impressed that this tread has managed to go on for 5 pages arguing over semantics. Horsepower vs. Torque is like asking what causes an eleictric motor to turn...voltage or watts? First, you can't have one without the other and second, voltage is a force and watts is power. There is a "step" of calculations missing in between them. Keeping with the electricity theme, it would be like a power company charging for the torque of their generators instead of power in Watts.
Which brings me to my point. Torque is a force and Horsepower is...well power. A force (torque in our case) does nothing unless applied over some vector. This can be measured in either distance or RPM's. Once a force is applied over said distance it does Work. This is described as Power and in our case written in the unit of HP. Think of it another way, wheel horsepower can be calculated 2 ways. First, by directly measuring the force the rear wheels applies to the ground over an RPM range on a dyno. Second, by calculating power from the the force needed to accelerate a car of a given mass from velocity A to velocity B over a given distance.
So, in conclustion, the answer is both. Torque is the physical force applied to the road by the rear wheels and Horsepower describes the amount of work done by that torque over a distance.
This probably does nothing to add to this thread, but I figured aince everyone was saying the same thing and different ways...I may as well, too.
Keep it up everyone. It is great to see that the art of a polite debate is not completely dead.
Registered User
Joined: Sep 2001
Posts: 565
Likes: 1
From: SF Bay Area
KnightRider,
Great post. It still boggles my mind how the average car consumer cannot grasp such concepts. It also leads me to ask some questions:
Why is engine torque even advertised? Isn't the consumer looking for something more like maximum thrust applied by the wheels?
Why did honda gear the S2000 the way it did (and thus causing people to complain about lack of thrust)? I have a feeling it has to do with keeping RPMs within VTEC range, and also gas mileage in 6th.
Why would a car company gear a car so it would break the tires loose at full throttle all through 1st, and sometimes 2nd? Shouldn't that torque be better traded for revvs? (I suspect the answer is that people *like* to do burn outs.)
Great post. It still boggles my mind how the average car consumer cannot grasp such concepts. It also leads me to ask some questions:
Why is engine torque even advertised? Isn't the consumer looking for something more like maximum thrust applied by the wheels?
Why did honda gear the S2000 the way it did (and thus causing people to complain about lack of thrust)? I have a feeling it has to do with keeping RPMs within VTEC range, and also gas mileage in 6th.
Why would a car company gear a car so it would break the tires loose at full throttle all through 1st, and sometimes 2nd? Shouldn't that torque be better traded for revvs? (I suspect the answer is that people *like* to do burn outs.)