Torque and Horsepower?

Question

Is torque acceleration or ability to stay at a high speed? Or is horse power acceleration or ability to stay at a high speed? Can you explain torque and horsepower? Can you give the definitions? What is torque good for? What is horsepower good for?

Answer 1

Dear Torque-



I read through the list of responses and I can truely say that you are not getting the answer you seek.



Automotive 101:



Touque as defined in a dictionary is the amount of twisting force necessary to move an object from a stopped position.



Well that is what they say as a standard answer. Yeah, whatever!



The definition for torque in the automotive sence of the word, is still relative, but it actually equates to how much force the engine is able to produce at a given RPM. This force, (torque) will dictate how much weight the engine can move efficently.



Street terms: Torque gets you going from a stop. Horsepower maintains the speed, (and increases it), at which you wish to travel, then maintains it until it "peaks out."



Horsepower comes into play after the torque peak. The torque peak gets you to the Horsepower Peak. The Horsepower Peak increases and maintains your velocity, (MPH/KPH).



Torque is mainly used in the low speed applications to get you to the high speed. At the higher speeds the Horsepower then jumps in to keep things going.



The common misconception is that when you are rolling around town you are using your Horsepower to move, or a good example of that is getting onto the highway. The power that you are using when you have the throttle wide open to get onto the highway is not Horsepower. Its Torque. Then when you are on the highway and you need to pass another car, that is the Horsepower, not the torque.



In a 1/4 mile Drag Race, the first half of the race is all about who has the better torque, and the last half is about who has the better Horsepower.



Torque and Horsepower are dictated by the Cam Shaft in the engine. For example, you can have two identical 350 enignes sitting side by side. Pistons, crank, block, heads valves, intakes, exhaust systems. the works. However, by changing merely the Cam Shaft only, you can make one of the engines have a greater Torque Peak, (Engines desiched for Motorhomes/Trucks), or and engine that has greater horsepower, (sports cars, muscle cars ect.).



Torque and Hosepower do have an element of balance though too. Normally the greater the Horsepower, the greater the Torque, but that is not always the case. For example, (Diesel Engines), normally in an automotve application, fairly low on the horsepower scale, but the torque capability is very high. How else do you explain, placing a 12 cylinder Diesel Engine in a Panzer Tank? Only 300 horsepower, almost twice the rating in torque, but it was not very fast.



That is the hitch with Torque. Torque is not speed, horsepower is speed, the more torque you have the sooner you get to use your speed.



Most of the Drag Engines, (Top Fuel Dragsters), they have engines that produce 5000 to 7000 horsepower from a 510 CID engine. But the Torque rating on those engines is approximately half of the Horsepower rating. Now yes 2000 Pound Feet of Torque Effort is impressive, but most of that energy is wasted with tire spin to get the "Cart" moving.



But I am not sure that you want to burn 25 gallons of fuel in 1/4 mile either, (Nitro Methanol).



Just a suggestion: If you have never been to a Top Fuel Drag Race, (NHRA Event), you should go and check this out. If you go get a pit pass, and if its possible have a chat with a couple of the pit crews, or their Docent. You will learn lots about the do's and the don'ts in your own project.



I hope that will help you out. Also, don't hesitate to talk to your local speed shop. The folks at these places are normally very helpful. Yeah, you might get a couple of different answers on the same subject. But that normally comes from the two persons different approaches for solving the same problem. The rule of thumb in that case is to err on the side of caution. Its normally less expensive! :)



Good Luck!

Answer 2

Torque is the power that an engine creates.



Horsepower is a description of how the engine creates torque in relation to rpm. (I think the relationship is horsepower=torque x RPM divided by 5252) Horsepower and torque are equal at 5252 rpm's.





Basically, if you create torque at low rpm, you create a good towing vehicle, or an engine that pulls a heavy car from the line with grace.



Building a high horsepower car is usually in order if you want a dragster that has power at high rpm, where you can use a clutch or high speed stall converter (torque converter) to make the car use the horsepower to get down the quarter mile quickly.



Many high-torque cars beat high horsepower cars at the dragstrip, because torque is what gets a car going. If you don't gear your car, or build it with the proper torque converter to take advantage of huge high-rpm horsepower, you will lose to a high torque car.



My Buick GS 455 has monstrous torque. I've slaughtered high-horsepower, heavily modified cars at the track, because they've not taken the whole equation into consideration!!

Answer 3

What Is Good Torque

Answer 4

Not quite. Horsepower is the potential ability to do work and how much. Torque is the twisting force applied in the case of a car to the wheels. Loads of horsepower without torque = no movement at all. Torque can be multiplied by the gearing and is in all automotive applications. generally the best performance in a car or on a bike is when the gearbox is used to keep the engine spinning between the lower highest torque rev speed and the higher best power rev speed. There is no magic formula but it is fair to say that with a reasonable amount of torque available them power output will determine top speed if all other things are equal. In vehicles the rolling resistance, mass and drag are what the power has to overcome with the result that a high torque 600 bhp volvo lorry is a lot slower than a 50 bhp motorcycle. As you can see because of this there is no direct correlation between power torque and speed.

Answer 5

The best way to describe torque is a twisting force. Multiply it by gearing and divide it by your tire size, and you have a good idea of the force that the car can put to the road. For example, if you have an engine making 200 lb-ft of torque, first gear is 2.74:1, your axle gearing is 3.55:1, and you have tires with a one foot radius, the car can put 200 * 2.74 * 3.55 / 1 = 1945.4 pounds of tractive effort to push it forward in first gear.



Horsepower is how much energy an engine can put out in a given amount of time. It sets a limit on the car's maximum acceleration (since acceleration requires increasing the car's energy) and top speed (one formula for power is speed times force).



For a given engine, both horsepower and torque will change with RPM. The engine always makes its maximum horsepower at a higher RPM than its maximum torque. You can calculate horsepower for a given RPM by taking torque, multiplying it by RPM, and dividing by 5252 (a conversion factor).

Answer 6

Torque is `power', hence acceleration. It is measured at the flywheel of the engine. The more torque an engine has the faster the car will be going though the `gears'. Horsepower is 2nd in importance as you will have a higher top speed with more horsepower. You need both, but in a 1/4 mile drag race I vote for torque! That is what `moves' the car.

Answer 7

Torque is the force required to move something.



Power is how quickly that force is applied.



Power is also energy. You cannot create additional power through gearing. Power at the wheels will always be less than at the engine due to frictional losses.



Torque can be multiplied using gearing.

Answer 8

Horsepower and torque are pretty close to the same thing, but not quite and they are usually given separately for car engines because they have different effects. A car with a lot of torque will have power at low RPMs and be able to get going from a standstill quickly, or while pulling a heavy load. A car with a lot of horsepower will accelerate rapidly through the higher RPM range.

Answer 9

Torque is the twisting force.. Horsepower is the ability to get work done.



Torque is the ability to change the Inertia of the vehicle.



Power is the ability to get work done.