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Posted by: mystereid
Torque is a twisting force, Horsepower is torque over an amount of time.
What you really want to describe is an engines power and at what rpm range it produces that power. Diesels make their power at low rpms so people say they are torquey. They just produce their power at low rpms. They are producing an immense twisting force with every stroke and so need to be reinforced with heavy blocks, cranks and rods. A high reving turbo fourbanger could put out the same horsepower but at a much higher rpm. Each stroke would have much less twisting force but it would produce the same result because of the extra rpms.
Posted by: Bubba297
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Originally posted by: BryceGTX
Torque=Force*LeverArmLength
HP=Torque*RPM/5252. torque in foot pounds
As someone said, torque is twisting force. Think of Torque as a force acting on a lever (torque wrench). You can have zero HP with high torque at zero rpm. HP is the product of torque and RPM. Generally, HP goes up with rpm. Torque may or may not go up with rpm depending on the engine type and the rpm range.
I hope this helpsBR>BryceGTX
Strongtyer, remember that a dyno can only measure torque and they use that to figure HP from. As Bryce stated torque and HP will always be the same at 5252rpm. In most cases (excluding diesels for sure) the torque and HP curves will be somewhat similar. Since torque is a leverage factor you will find that many longer stroke motors will yield a great deal of torque than motors with shorter strokes. A shorter stroke motor (take a Banshee for instance) will make some good torque numbers, but usually at a very high RPM in relation to other motors.
A motor with a lot of torque will generally be fun and feel fast. Some people dont like the Banshee because of the lack of bottom end power. It's not that the motor doesnt make torque, it just does it higher up the RPM scale. Also generally speaking a big torque motor will have a lower top RPM than a smaller torque motor. 4-stroke motors have more torque than 2-strokes because they use a full 1 stroke for the power stroke. Most 2-strokes only use between about 26-36 degrees of crank duration for their powerstroke. That's a lot of difference between 180 and 36. I hope that didnt confuse anyone, it's too da@# hard to put this crap on paper sometimes.
Posted by: Bubba297
I know that a standard diesel like that wont turn 5252 running on the road, but if you did a dyno and looked at the graph, the lines would intersect at 5252. The torque would rise greatly early while the hp rose a little bit, then the torque line would fall down at meet the other at that point.
Posted by: Bubba297
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Originally posted by: 440EX026
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Originally posted by: 86LT250RFatty
put it this way. In a 1/4 Mile.... HP is Speed, Tourqe is Time.... to an extent.
Not the first time I have heard that, and I do agree with that thinking. I remember when I was much younger (maybe 8 or 10) wondering and asking why some guys could win races consistantly with lower top speeds, and the explanation was very similar to what you posted, and oddly I still remember it hr>
That's right. for example.......
My old 70 chevelle drag car ran a 377 small block chevy. We ran a 1000ft track, right between 1/8 and 1/4. With the original combo the car had 1.44-1.45 60ft times and ran 8.6's and 8.7's at around 113-114mph and that was shifting at around 6800rpms. Now when I tore the motor down I changed cams and went to a higher duration and lift. The car still ran consistent 8.6's, but things were reverse at the start and end. The 60ft times came up to around a 1.47-1.48, but the trap speed increased to 116-117mph and shifting occured at around 7000-7200rpms. The first motor combo made more torque in the middle and would holeshot hard, but the second combo made more HP on top end which resulted in a higher trap speed. Overall more torque especially lower on the rpm range makes for a lot more fun driving or riding.
Posted by: 440EX026
Some great answers !!!!!
To keep it simple I say that hp is impressive, but torque moves me.
Posted by: 440EX026
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Originally posted by: 86LT250RFatty
put it this way. In a 1/4 Mile.... HP is Speed, Tourqe is Time.... to an extent.
Not the first time I have heard that, and I do agree with that thinking. I remember when I was much younger (maybe 8 or 10) wondering and asking why some guys could win races consistantly with lower top speeds, and the explanation was very similar to what you posted, and oddly I still remember it
Posted by: petedog
my definition of torque:
Trying to take a pee in the morning with morning wood................
Posted by: waynerod
Wow! I actually get to use some of my physics here!
I would say that Torque = Force x Distance (Really its 'Force cross Distance' - cross is breaking up the force into components and only using the perpendicular component)
The magnitude - or measurement - of the torque is :
[perpendicular component (of the force being applied)] x [the distance between the object&39;s rotation point and where you apply the force].
In toher words - more torque = more power - right?
Now to define power.....
Posted by: TrailBlazerguy250
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Originally posted by: Hillbilly920
Torque is basicly the power and engine puts out. Most people think that horsepower is what makes an engine powerfull. Horsepower u want for speed, Torque u want for raw power
this will tell u all u need to know
torque
i agree
Posted by: Choky
If a little martial-arts guy come running at you with a flying kick,thats HP,if the govener of Cali(Arnie S.)when he was younger puts you in a wrestling move and pops your limb out of socket,thats torque...who agrees?I just made it up BR>
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Ok seriously,simply put for average guys like you and me...its the brute turning strenth your motor has.Torque will pull more weight,hp will push more speed.
Posted by: HughJazz
Torque is how much work you can do
Horsepower is how fast you can get it done
Posted by: ostrich
of course as we all know torque equals the force required to get an object moving, horsepower equals the amount of force required to move an obect over a cetain distance, simple?
Posted by: rolsmojave3
horse power may put holes in the ground but the torque got you in front
Posted by: 86LT250RFatty
put it this way. In a 1/4 Mile.... HP is Speed, Tourqe is Time.... to an extent.
Posted by: ss97
SIMPLE
To keep is as simple to understand as possible, and this is an abstract but effective description
TORQUE is what gets you moving.
HP is what keeps you moving.
Posted by: nosliw
torque is what gets you going, horsepower is what keeps you going. torque is what wins races, and is what people should be concerned about instead of hp. imo.....
Posted by: nosliw
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Originally posted by: Bubba297[/bAs Bryce stated torque and HP will always be the same at 5252rpm.
always? like in my diesel truck the redline doesnt go that high, but if it could would they be the same? is that principle?
Posted by: nosliw
wow so it always does. that's a really cool little thing to know.
Posted by: nosliw
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Originally posted by: BryceGTX
Hello guys. Lets put some numbers to it. Suppose you have a diesel that puts out 400 foot pound at 1500 rpm. It then puts out:
400*1500/5252 = 114 hp
Now lets look at the diesel when it puts out 400 foot pounds at 3500 rpm
400*3500/5252 = 266 hp
Like Bubba297 says, this is how a dyno controller calculates horse power. It measures the speed, measures the torque and simply multiples the two values and divides by 5252.
BryceGTX
at what rpm does it assign that hp? same as torque?
Posted by: delow350
well said hp is over done people are always talking about hp but completely over look the most important aspect. the keys to a well built engine are torque, quick reving, and a high red line.
Posted by: BryceGTX
Torque=Force*LeverArmLength
HP=Torque*RPM/5252. torque in foot pounds
As someone said, torque is twisting force. Think of Torque as a force acting on a lever (torque wrench). You can have zero HP with high torque at zero rpm. HP is the product of torque and RPM. Generally, HP goes up with rpm. Torque may or may not go up with rpm depending on the engine type and the rpm range.
I hope this helpsBR>BryceGTX
Posted by: BryceGTX
Hello guys. Lets put some numbers to it. Suppose you have a diesel that puts out 400 foot pound at 1500 rpm. It then puts out:
400*1500/5252 = 114 hp
Now lets look at the diesel when it puts out 400 foot pounds at 3500 rpm
400*3500/5252 = 266 hp
Like Bubba297 says, this is how a dyno controller calculates horse power. It measures the speed, measures the torque and simply multiples the two values and divides by 5252.
BryceGTX
Posted by: BryceGTX
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at what rpm does it assign that hp? same as torque?
HP is the same as torque when rpm is 5252. HP is the same as RPM when torque is 5252. Altough this is an interesting view of the equation. The fact is, HP is simply the product of torque and rpm. If the power is w, torque is in Nm and speed is radians per second, there is no 5252.
Power (w) = Torque (Nm) * Speed (rads/s)
In this case, when the speed is 1 radian per second (9.5 rpm), Torque and Power are the same!!
Posted by: BryceGTX
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Originally posted by: Bubba297
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Originally posted by: 440EX026
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Originally posted by: 86LT250RFatty
put it this way. In a 1/4 Mile.... HP is Speed, Tourqe is Time.... to an extent.
Not the first time I have heard that, and I do agree with that thinking. I remember when I was much younger (maybe 8 or 10) wondering and asking why some guys could win races consistantly with lower top speeds, and the explanation was very similar to what you posted, and oddly I still remember it hr>
That's right. for example.......
My old 70 chevelle drag car ran a 377 small block chevy. We ran a 1000ft track, right between 1/8 and 1/4. With the original combo the car had 1.44-1.45 60ft times and ran 8.6's and 8.7's at around 113-114mph and that was shifting at around 6800rpms. Now when I tore the motor down I changed cams and went to a higher duration and lift. The car still ran consistent 8.6's, but things were reverse at the start and end. The 60ft times came up to around a 1.47-1.48, but the trap speed increased to 116-117mph and shifting occured at around 7000-7200rpms. The first motor combo made more torque in the middle and would holeshot hard, but the second combo made more HP on top end which resulted in a higher trap speed. Overall more torque especially lower on the rpm range makes for a lot more fun driving or riding.
The reason this happens is that you cannot keep the engine at its peak HP throughout the run. Now if you have something like a CVT transmission, you can make use of the peak HP and your ETs would be lower. This is one reason snowmoble engines that put out such high horsepower and are so high strung accelerate so quickly.
Posted by: BryceGTX
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of course as we all know torque equals the force required to get an object moving, horsepower equals the amount of force required to move an obect over a cetain distance, simple?
Almost, but HP is dependent on the time taken while the force is applied. The lower the time, the higher the HP. The time comes in RPM or rev/min.
BryceGTX
Posted by: BryceGTX
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Another way to think of torque is the ability to create an increase in RPM. An engine with a large amount of torque at a low RPM but relatively low horsepower will have the ability to quickly increase that RPM, giving you that instant, neck snapping accelaration when you punch the throttle versus an engine with relatively low torque but high horsepower at high RPM, where when you punch the throttle the accelaration comes on in a more gradual but steady surge
Well this is almost true, but one thing you have to include in this discussion is inertia. If the inertia of the engine and drivetrain is too high, your acceleration is low. A good example is a diesel engine. These engines crank out high torque at low rpm. And the throttle response is faster than a gas engine. However, one reason it cannot accelerate as fast because they typically have much higher inertia than the gas engines. Let me give you a starting equation:
Torque=Inertia*Acceleration
To state it another way, the acceleration is directly proportional to torque and inversely proportional to inertia.
BryceGTX
Posted by: strongtyer
i was trying to explain to my friend what torque is but i couldnt really get the point accross on what it is. it seemed a little hard to explain and it kinda made me wonder if i know what it really is. how would YOU explain what torque is? thx
-strongtyer
Posted by: strongtyer
so is torque like how fast you can "get" your horsepower? what is the relation between horsepower and torque? you hear ppl see a car burn out and they will say man that has a lot of horsepower. should it really be torque? i got lost in that physics stuff and im even taking physics. hmm... anyways, thx for the replies
Posted by: MXF
Torgue is simply the rotational force applied to an axis. If measured in pounds at a distance in feet from the axis (center of rotation), then it is expressed in foot pounds or pound feet. If measured in pounds and inches, then it is expressed as inch pounds (commonly used to compare cordless drills to each other). In the metric system it is measured in newtons (force) and meters (distance).
If you take a lug wrench with a 10 foot long handle for example, and apply 100 pounds of force to it exactly 1 foot from the lug center, you are generating 100 foot pounds of torque. If you apply 10 pounds of force 10 feet from the lug (i.e., at the end of the handle) you are also generating 100 foot pounds of torque. So you might say that it is easier to generate that 100 foot pounds of torque by applying 10 pounds to the end of a 10 foot lug wrench, rather than 100 pounds at 1 foot from the lug. Well, that's true, but to turn that lug one complete revolution, you will have to apply that 10 pounds of force through a distance of 62.83 feet, whereas with the 100 pounds at one foot you only have to apply the 100 pound force through a distance of 6.283 feet. If you can perform one rotation of the lug in the same amount of time for each case, you are generating the same amount of power.
One horsepower is the amount of power required to lift 550 pounds, 1 foot in one second or ((550 pounds x 1 foot)/second)). This was determined a long time ago as the amount of power the average horse could put out over a relatively long time. A human can put out one horse power for a few seconds, for example a weight lifter bench pressing 550 pounds one foot in one second would be one horsepower. If you lift 110 pounds 5 feet in one second you are also generating one horsepower. Since torque and horsepower are usually expressed as a function of revolutions per minute (RPM) not revolutions per second (RPS) it helps to think of one horsepower as the amount of power required to lift 33000 pounds, 1 foot in one minute, or 1 pound 33000 feet in one minute. This is just taking 550 x 60 seconds = 33000. Keep in mind that a circle with a radius of one foot has a circumference of 2 x PI or 6.2831853 feet. Also, 33000/6.2831853=5252. To determine the Horsepower, you need to know the torque (in foot pounds) at a given RPM using the equation HP = Torque x RPM/5252. To determine Torque, you need to know the Horsepower at a given RPM using the equation Torque = HP x 5252/RPM
So now think of the crankshaft of a V8 engine rated at 200 horsepower and 250 foot pounds of torque. The torque is the maximum twisting force that the V8 can generate (250 foot pounds) and this peak torque is only spec'd at a specific rpm. At all other rpms it is less. So lets say the 250 foot pounds of peak torque comes at 2500 RPM and that the 200 horsepower comes at 4500 RPM.
At 2500 RPM, 250 foot pounds is equivalent to lifting 250 pounds through a distance of 15707.963 feet in one minute (2500x 2 x PI, where PI =3.1415927). This is equivalent to lifting 1 pound a distance of 3926990.8 feet (250 x 15707.963). So dividing that by 33000 = 119 horsepower. A simpler way to do it is to first divide 33000 by 2xPI which equals 33000/6.2831853 = 5252. So then just take torque (in foot pounds) x rpm/5252, or 250 x 2500/5252=119 HP.
So if the V8 generates 200 HP at 4500 RPM, thats 200 x 5252/4500=233.4 foot pounds of torque.
So you can see that even though the V8 is generating less torque at 4500 RPM, it is generating 1.68 times as much horsepower as it does at 2500 RPM.
Another way to think of torque is the ability to create an increase in RPM. An engine with a large amount of torque at a low RPM but relatively low horsepower will have the ability to quickly increase that RPM, giving you that instant, neck snapping accelaration when you punch the throttle versus an engine with relatively low torque but high horsepower at high RPM, where when you punch the throttle the accelaration comes on in a more gradual but steady surge.
Posted by: Morewood
This is a really good way to think of it: (from HughJazz)
"Torque is how much work you can do -
Horsepower is how fast you can get it done "
Torque is force, like foot-pounds.... think strength.
HP is that force over time, how "fast" you can deliver that force to the wheels or ground, where ever you chose to measure it.
Each different racing application will need the particular optimum combination of these two, it's not always the same answer. Torque might be more important to trail riders, and HP might be more important to drag racers.
Posted by: DLRPLATE
Torque is what you feel horse power keeps you accelerating. Torque = quick hp = speed.
Posted by: DLRPLATE
WOw is right! You lost me man
Posted by: Hillbilly920
Torque is basicly the power and engine puts out. Most people think that horsepower is what makes an engine powerfull. Horsepower u want for speed, Torque u want for raw power
this will tell u all u need to know
torque
