View Full Version : what does torque mean!?!?!?
um can some one define to me what torque means i think i know what it means but not sure :p thanx :) :D :) :D :) :D
Technically Torque = Cylinder Pressure x Cylinder Capacity, but i have no idea how to use that (im guessing cylinder pressure is the compression ratio.)
Someone will DEFINATELY provide a better explaination, but i would think it defines the tractability of an engine, ie ability to pull from X revs, also the expression of power is derived from torque, because.....
Power = Torque * RPM
So a bike (or car) that has lots of torque will make its power low down the rev range, this is due to the fact that a big engine (or one with less cylinders, like the SV) will have a longer stroke and bigger power pulses per cylinder, so because of the long stroke it cant rev as high, but the power that is made in each cylinder is bigger, due to the larger capacity.
I cant think of much more right now...
lol well i am a noobie and dont realy understand wot u just sed that well, i kinda get ya but i think ill need to read it a few times to understand it, if there is another way you or some one els can explane it that would be gr8 heh :p
If I can remember my GCSE Physics lessons :lol: torque is the force that turns or rotates things. Like if youre tightening a screw, youre applying torque to it
Torques measured by the force youre putting on it X the distance from the centre of the object. Its in lb/ft so if you were using a foot long wrench on a nut and putting 200lb of pressure on it the torque would be 200lb/ft
Got it? No? Good,neither have I :lol:
Basically I think the pistons go up and down in the engine and they turn the crankshaft, producing the torque. More torque in an engine means more low down grunt and faster overtaking :riding:
My head hurts now im going for a lie down :mrgreen:
erm well.
I hoped you understood the bit on basic torque.
The stroke and torque bit could be explained better.
Ok hold your arm infront of your face with your elbow bent, now move it upwards to the full extension of your arm, then back down to starting position and back up again, you cant do it very much due to you arm having to travel all the way up, this is like a long stroke cylinder, however, move it halfway to where it was and back down, you can do it many more times, this is a high revving short stroke cylinder.
Now, this is why cars dont rev as high as bikes, because bikes have smaller engines and shorter stokes.
So remember
Bigger engines = more torque (which means power is created lower in the rev range)
Less Cylinders = more torque ( a 600CC single cylinder will have a much longer stroke than a 600CC 4 cylinder engine) but it wont rev as high, hence less power due to Power = Toque * rpm.
That could probably be more simple again but ill have to get thinking
So is torque just another word for power then like how mutch power the engine is giving out? :-k
yep, power doesnt exist though, only torque exists in the real world.
Power is derived from toque, but yes torque is a measurement of power.
yep, power doesnt exist though, only torque exists in the real world.
Power is derived from toque, but yes torque is a measurement of power.
i might attempt an explanation tomorrow, but for the moment you're confusing the poor lad. Torque is basically a measure of force and power is a measure of work done in a certain amount of time. Torque most certainly is not the same as power.
:cry: <--- Poor Confused Lad
yep, power doesnt exist though, only torque exists in the real world.
Power is derived from toque, but yes torque is a measurement of power.
i might attempt an explanation tomorrow, but for the moment you're confusing the poor lad. Torque is basically a measure of force and power is a measure of work done in a certain amount of time. Torque most certainly is not the same as power.
I meant power in BHP terms not as in Power = Energy/Time, not many people use wattage for engines, apart from the silly DSA.
I admit i am confusing things though, i know what im thinking, i just cant put it down on the screen, probably explains my exam results :lol:
Sorry Didge :roll:
I do study physics though, and (ignore this didge) Torqe = force * distance, but also work = force * distance.
So, because work is energy (kinetic energy here) Power = Force * distance/ time so thats actual torque over time, as in the RPM right?
So power is directly linked to torque, no matter what its form
:cry: <--- Poor Confused Lad
you'll get about 10 different explanations, some of which will make sense and some of which won't. People just have different ways of trying to explain things. At least one person will be right but you'll have no idea which. After around 3 or 4 pages of people bickering over the finer points, you will have lost interest and still be none the wiser.
Have we had these discussions before? oh yes :D
Welcome to the forum, btw :lol:
lol ty no its ok both of u have been gr8 im sure some one will explane it in a way ill under stand soon thank u both any way :p kinda funny watching u 2 battle it out :P :D :P any way im goina t obed now ill hav another read to morrow morning nn
I meant power in BHP terms not as in Power = Energy/Time, not many people use wattage for engines, apart from the silly DSA.
I admit i am confusing things though, i know what im thinking, i just cant put it down on the screen, probably explains my exam results :lol:
Sorry Didge :roll:
Don't let the units get in the way. Power in bhp is still energy/time, same as watts or any other measure of power you care to think of. Much as I hate to admit it, imho metric units such as watts make so much more sense than daft units such as horsepower.
I do apologise for not volunteering an explanation right now but its really too late for my brain to get into gear. I'm hereby going to crawl back under my rock until i can be more useful.
Were not battling, these discussions happen always, and i love them, when you get big long pages like this.
You learn loads no matter what your opinion, and engine discussions are what interest me most, there nought more interesting than an internal combustion engine i reckon.
I meant power in BHP terms not as in Power = Energy/Time, not many people use wattage for engines, apart from the silly DSA.
I admit i am confusing things though, i know what im thinking, i just cant put it down on the screen, probably explains my exam results :lol:
Sorry Didge :roll:
Don't let the units get in the way. Power in bhp is still energy/time, same as watts or any other measure of power you care to think of. Much as I hate to admit it, imho metric units such as watts make so much more sense than daft units such as horsepower.
I do apologise for not volunteering an explanation right now but its really too late for my brain to get into gear. I'm hereby going to crawl back under my rock until i can be more useful.
Yea but when you study you always learn in watts and newtons etc, thats why its easier, like when my dad talks in imperial its like another langauge and to him its easier than metric, strange.
I trust i too will be learning stuff when Ophic is awake tommorow, i wish there was an Engine class in college, i dont think id ever lose interest.
its not entirely relevant to engines but see how you get on with this:
http://science.howstuffworks.com/fpte4.htm
now i'm off to bed :)
the simplist way to describe torque, is that it is a measurment of leverage
All you need to know is that torque means acceleration! For example, the SV has "low-end torque", meaning low end acceleration. Right?!
Hi Didge,
First of all... welcome to the site, where abouts in Tunbridge Wells are you? I used to live there, and still frequent the area often!
Torque and BHP are often areas of confusion. I've not read all this thread, and I'm sure others have attempted to describe the difference, but let me have a go too! :lol:
Torque is measured as force x length (eg: Lb-Ft). Essentially this figure describes the rotational force that an engine can create. Similarly to opening a jar of pickles for your Mum - she may not be able to create enough torque on the lid of the jar, but given to her trusty iron-fist son (me), who can effectively twist the lid harder and apply the necessary torque to open the lid. That's how it works with my folks anyway :wink:
BHP is a measurement of the amount of practical work an engine can do. Historically, 1 Horepower, is the amount of work required to lift 33,000 lbs of weight, 1 foot in the air. Sounds a bit silly I know :lol: This can also be expressed as foot-pounds-per-second. Therefore, 1 Hp is 550 Fps. In a nutshell, BHP is a measurement of how fast an engine can deliver it's power.
Hugely simplified explanations... and hopefully not contradictory ones. I do hope I've not given incorrect advice ;)
All you need to know is that torque means acceleration! For example, the SV has "low-end torque", meaning low end acceleration. Right?!
wrong. Power means acceleration. Torque is more of an engine characteristic that tells us how it delivers that power. This is why manufacturers quote power to weight ratios not torque to weight. However one effect of lots of torque low down in the rev range is that the engine also develops quite a lot of power low down - and hence you have your low end acceleration. But an engine that produces more power, even at higher revs, if geared down, will accelerate faster, even if it produces less torque.
Explaination 1:
Torque = a dyslexic's version of talk; to chat, communicate, discuss, impart information in a verbal manner. :wink:
Explaination 2:
I have no idea, it's something to do with making things go round! :?
Explaination 3:
It's something lots of people go on about, alot. Usually ending up in some kind of macho-driven one-up-manship resulting in "my bike's better than your bike!." :roll:
Explaination 4:
See Explaination 3, but avoid such conversation because you are aware of the simple fact that complete ignorance of how your bike actually works doesn't necessarily make you a bad biker, or ruin the simple enjoyment of riding said lump of machinery! :wink:
Explaination 5:
See Explaination 2 but add the important fact that I have a thing called a 'Torque Wrench' - it has little numbers on it that I know are important = (A). These numbers are also printed in my workshop manual = (B).
I know when to appy (B) to (A) so that my rear wheel, and other important bits on my bike I dare fiddle with, don't fall off or break. This to me is the singular thing I actually know about Torque, and the only one I consider important for me. 8)
In all, I hope that helps, if not, at least gives your brain a break from all thses intelligent people who are making my head hurt. :P
Historically, 1 Horepower, is the amount of work required to lift 33,000 lbs of weight, 1 foot in the air.
In how long? Horsepower is a measure of power, not work, so there needs to be time in there somewhere.
(In fact its one minute. 1HP = amount of power required to lift 33,000 lbs of weight, 1 foot in the air in one minute)
K :lol: You're not helping ;)
However you are forgetting:
Explanation 6:
Torque, a crappy film about bikes made by Hollywood.
Historically, 1 Horepower, is the amount of work required to lift 33,000 lbs of weight, 1 foot in the air.
In how long? Horsepower is a measure of power, not work, so there needs to be time in there somewhere.
(In fact its one minute. 1HP = amount of power required to lift 33,000 lbs of weight, 1 foot in the air in one minute)
Yes sorry, I missed that bit out :oops: however I feel I redeem myself at the mention of 550 foot-pounds-per-second. So 1 Hp is the ability to raise 550 lbs, by 1 foot, in 1 second. (Or 33,000 by 1 foot in a minute).
alright my turn.
Torque is the turning force than an engine produces. As RandyO says, it can be referred to as leverage. Now obviously an engine doesn't produce a smooth force but rather pulses of it as the cylinders fire. So I think of torque as the average turning force produced over one revolution of the engine.
So the more torque produced the more force the engine puts out so the faster we accelerate, right? Yes, up to a point. Revs also play a part as they determine how "often" the engine delivers its torque.
Now it gets a bit more complicated. As the revs rise, the engine produces more torque until it reaches its peak torque rpm - somewhere around 7000-7500rpm on an SV. Now after the peak, the torque produced actually drops off, but it does so gradually (at first). As the revs go past this point, the torque decreases but the revs continue to rise, meaning that the engine delivers less torque but more often. This increase in frequency more than compensates for the drop off in torque, so the amount of power delivered keeps on rising - up to the point where the engine is developing peak power. This is the real "sweet spot" of the engine and where you will find it accelerates the fastest.
After peak power the torque drops off more quickly than the increase in revs can compensate for, and hence the power output goes down and the engine is now past its best - at this point its time to cog it up a gear and start all over again :wink:
Cant wait to see what didge makes of that :lol:
K :lol: You're not helping ;)
However you are forgetting:
Explanation 6:
Torque, a crappy film about bikes made by Hollywood.
No, I deliberately left that out in an attempt to eradicate it from my memory - which you have now brought flooding back. :evil:
Oh the horror, the horror! :shock: :wink:
There are two ways of making an engine produce lots of power - you can increase its torque, or you can make it produce that torque at a high rpm. If my engine produces 60Nm of torque at 7000rpm and i wanted to make it twice as powerful, i could theoretically make it produce 120Nm of torque at 7000rpm, or i could make it produce 60Nm of torque at 14000rpm.
To make it produce twice the torque i'd have to double the size of the cylinders. Revving twice as high would keep the cylinders the same, but they would fire twice as often.
One way of thinking about it is to imagine the amount of fuel an engine consumes. Big low revving engines will consume a lot of fuel every rev. Small screamers will consume not much per rev but they'll do it very often.
Cant wait to see what didge makes of that :lol:
well it made sense to me :oops:
Bigger engines = more torque (which means power is created lower in the rev range)
Sorry jp - this only partly right. It is the lower in the rev range bit which is not necessarily correct - where peak power/torque is made in the rev range is engine-dependent. There's no hard and fast rule.
Less Cylinders = more torque ( a 600CC single cylinder will have a much longer stroke than a 600CC 4 cylinder engine) but it wont rev as high, hence less power due to Power = Toque * rpm.
Sorry again, but this bit is total bollox.
A Fireblade or R1 makes more peak torque than a Duke 999.
As for how Power & Torque relate to each other, see below (source: http://www.pumaracing.co.uk/power1.htm)
HOW TORQUE AND POWER RELATE
Let's imagine we have a pulley at the top of a mine that is 1 foot in radius - or 2 feet in diameter. At the bottom of the mine, at the end of a rope leading round the pulley is a bag of coal weighing 100 pounds. Instead of using a horse to pull on the rope let's connect an engine to the pulley - perhaps by bolting the pulley to the crankshaft of the engine.
In order to lift the coal we need to apply a torque of 100 foot pounds to the pulley because the coal is pulling down with a force of 100 pounds applied at 1 foot from the axis of rotation. In other words the Torque applied is the Weight times the Radius of the pulley. If the engine turns the pulley at 1 revolution per minute how much work is being done?
Well for each turn of the pulley the coal will rise the same amount as the circumference of the pulley which is 2 pi times the radius = 3.14 x 2 = 6.28 feet. So in 1 minute the engine will do 628 foot pounds of work. Copyright David Baker and Puma Race Engines
We can rearrange the above in terms of torque and speed:
The rate of work being done (or Power) is Force x Distance per minute = Weight x radius x 2 pi x rpm foot pounds per minute. However we already know that Weight times Radius = Torque so we can equally say:
Power = Torque x 2 pi x rpm
To turn this into Horsepower we need to divide by 33,000. Our final equation therefore becomes:
Horsepower = Torque x 2 pi x rpm / 33000 which simplifies to:
Horsepower = Torque x rpm / 5252.
This is the universal equation that links torque and horsepower. It doesn't matter whether we are talking about petrol engines, diesel engines or steam engines. If we know the rpm and the torque we can calculate horsepower. If we know horsepower and rpm we can calculate torque by rearranging the equation above:
Torque = Horsepower x 5252 / rpm
Hopefully you can also see that when an engine is turning at 5252 rpm, its torque and horsepower figure is the same. Next time you see a graph of the torque and horsepower of an engine check to see that the lines cross at 5252 rpm. If not then the graph is wrong. This only applies of course if the power is being measured in horsepower and the torque in foot pounds and both lines are shown on the same axes. There are many other units in which torque and horsepower can be measured - for example power can be measured in Watts and torque in Newton metres. Unless we need to convert to such continental measures we can usually stick to horsepower and foot pounds.
:lol:
Jabba... next time I go for a blast I'll take my calculator ;)
:lol:
Jabba... next time I go for a blast I'll take my calculator ;)
Nah...............just take a web-enabled PDA :wink:
MattTheLoony
30-06-05, 11:57 AM
BHP sells cars/bikes, torque turns wheels
I was talking in terms of per cylinder, not the whole engine.
I should have stated per cylinder but it was late and i should have proof read it really :roll: :roll:
A ducati makes more torque per cylinder than an R1 simply because it has larger stroke cylinders.
And wouldnt bigger engines have longer strokes, i cant think of any engines that are under square now, and to be practical most engines are in pretty much the same band (ie bore and stroke) for that cylinder size, like a 4 cylinder 600 Hornet will have pretty much the same bore and stroke as a CBR 600 right (i know its the same engine) ?
Just as a general question, how can the 3 litre F1 engines rev so high, do they have tiny strokes and massive bores or somethin?
BHP sells cars/bikes, torque turns wheels
:notworthy:
I don't think we can start complicating matters with discussions on engine design and configuration; then we'll have to start talking about the effects of gearing and so on. We can't generalise, but we can give an idea what the two terms mean, because they're inextricably linked.
However, we can, in simple terms, describe what the two terms mean in the real world. I think that's been done here, so I won't do it again. :lol:
Just as a general question, how can the 3 litre F1 engines rev so high, do they have tiny strokes and massive bores or somethin?
Yep - and lots of cylinders, meaning very light pistons, lower inertia and lower reciprocating mass. They're also made out of high-tech, very strong and expensive materials that aren't cost-effective on mass-produced machinery.
They also aren't expected to last over 100,000miles..............
Rob S (Yella)
30-06-05, 01:08 PM
Is frank Bruno twice as strong as Linford Christie. Probably.
So imagine a twin cyl engine (SV) is powered by 2 Big franks and a 4 cyl GSXR is powered by 4 Linfords.
The four linfords are are as powerful as the 2 franks and can go faster but have less pushing power.
So if your car is being pushed by the 4 linfords they will get a good turn of speed out of it but may struggle to get it moving or push it up a kerb or over a hill.
The 2 big Franks will get the car moving easier and hills just wont matter but they are heaveir and slower at the top speed. so thats why you need torque for a good push in any gear and to get you going and move the weight.
BUT: once on the go you want power to speed you up and get a good top end.
SO if you think about 2 franks or 4 linfords pushing a car from a standing start you will see where the power and the torque each have there own adavantages.
Or am I mad.
Check out the How stuff works site, this page :idea:
http://science.howstuffworks.com/fpte.htm
Is a good place to start it covers the wider topic of Power, but it deals with torque and has some nice animations
Hope it’s of some use for the original posting
Is frank Bruno twice as strong as Linford Christie. Probably.
So imagine a twin cyl engine (SV) is powered by 2 Big franks and a 4 cyl GSXR is powered by 4 Linfords.
The four linfords are are as powerful as the 2 franks and can go faster but have less pushing power.
So if your car is being pushed by the 4 linfords they will get a good turn of speed out of it but may struggle to get it moving or push it up a kerb or over a hill.
The 2 big Franks will get the car moving easier and hills just wont matter but they are heaveir and slower at the top speed. so thats why you need torque for a good push in any gear and to get you going and move the weight.
BUT: once on the go you want power to speed you up and get a good top end.
SO if you think about 2 franks or 4 linfords pushing a car from a standing start you will see where the power and the torque each have there own adavantages.
Or am I mad.
you are mad :P
power is power, whether its pushing you up hills or pulling away or speeding you up. A revvy 250bhp engine will go up hills that a 200bhp diesel torque monster won't. The only difference is at what revs the engines would be running at.
Just to confuse the matter further a GSXR600 produces more torque than an SV, just at much higher revs :wink:
Check out the How stuff works site, this page :idea:
http://science.howstuffworks.com/fpte.htm
Is a good place to start it covers the wider topic of Power, but it deals with torque and has some nice animations
Hope it’s of some use for the original posting
I already posted this, but its worth reading twice - darn good site :D
Sid Squid
30-06-05, 03:17 PM
Re: Torque, Embee wrote this. (http://forums.sv650.org/viewtopic.php?p=231281&highlight=#231281) Which is as neatly and comprehensively written and explained as everythnig else he scribbles for us to learn from.
Explanation 6:Torque, a crappy film about bikes made by Hollywood.
Yep, he's got it!
[
Just to confuse the matter further a GSXR600 produces more torque than an SV, just at much higher revs :wink:
more peak torque, but the SV has a much flatter torque curve, and at anything lower then peak, the SV is putting out more
Biker Biggles
30-06-05, 08:18 PM
A couple of things spring to mind after all this.
!. Torque is cheap.
2 Careless torque costs lives.
3 Time for a beer. :D
http://www.dur.ac.uk/r.g.bower/PoM/pom/node11.html
May help
Cant wait to see what didge makes of that Laughing
lol i think im getting it jsut spent the last 20 mins reading thru the whole thread :o :P:D:P
Hi Didge,
First of all... welcome to the site, where abouts in Tunbridge Wells are you? I used to live there, and still frequent the area often!
hello, i live near umm skinners school <--- ring a bell :/ or umm st lukes church :O
tomjones2
02-07-05, 05:55 PM
a most informative thread
now i have got a headache though my brain wasent designed to take in that much information
NitroNorry
03-07-05, 08:32 AM
Is the problem here that people are trying to define what torque is in totally classical (and correct) terms.
Most people use the word torque or torquey to mean that a bike (or car) pulls well at low revs - so for example an SV is torquey although it has nothing like the power of a CBR600RR at high revs.
Probably be put on a hit list by the clever guys out there now :x
Martin
lol no its ok i just wanted to know what it ment i didnt know that there was loads of stuff to it but i hav lournt alot form asking thats why i come on here every day now to c any other cool info i can scrounge of people :PD:P:D:P
Most people use the word torque or torquey to mean that a bike (or car) pulls well at low revs - so for example an SV is torquey although it has nothing like the power of a CBR600RR at high revs.
You're totally right. But what the usual problem with torque is, is people don't understand its relevance. Some people believe its a more important figure than power in terms of performance. Anyway there are lots of myths about torque floating around that aren't at all true, and I often find myself explaining more about what it isn't than what it actually is.
i c well thanx any way for your help with i im sure im gona ask some other random question soon that your gona fill meh head with loads of usefull stuff :p once again thanx for ya help :notworthy:
ur welcome didge. Feel free to ask away. Anything more hands on than pure theory is totally beyond me, btw :D
lol u know loads bout theory then > :D:P:D:P:D
okay.... i think im following all this now....
torque is the amount of horses your bike can pull at once.
BHP is the amount of horses your bike can knock down at full speed?
errrm im gona w8 till some one els reply till i go with that cos i sed suming like that and i was wrong :(
okay.... i think im following all this now....
torque is the amount of horses your bike can pull at once.
BHP is the amount of horses your bike can knock down at full speed?
nope. Both examples above are related to power.
Engine A: peak power 100bhp @ 20,000rpm
Engine B: peak power 100bhp @ 3,000rpm
Both engines will do exactly the same, will accelerate just as fast as each other, are capable of the same top speed, and will pull just as much weight.
The difference between the two is how they produce the power. Engine A hasn't got much torque and produces its power by getting its revs really high. Engine B has lots of torque and produces its power without really appearing to work that hard ie at low revs. The difference is the characteristic of the engine, not the capability. It makes a huge difference to how the engine feels to drive. Also engine B is likely to last a lot longer than engine A, as it doesn't have to scream its nuts off to get anywhere. However engine B will also most likely have a much larger capacity - therefore it will use more fuel on tickover, and probably be much heavier - hence reducing the acceleration of the vehicle it is in due to its own weight. Engine A, however, would probably be an absolute nightmare to try to drive.
Torque has nothing to do with what an engine is actually capable of. It is more related to what the characteristics of the engine are suited to. It is important - but its not really a performance factor.
perhaps i should have added some of these in my post -
:D :) :o 8) :lol: :P :wink:
it was supposed to be a joke........ which sums up my sense of humour. :roll:
Carsick
04-07-05, 07:26 PM
perhaps i should have added some of these in my post -
:D :) :o 8) :lol: :P :wink:
it was supposed to be a joke........ which sums up my sense of humour. :roll:
it's ok, I got it, I laughed even harder when somebody replied though. :wink:
i dont get it :S hens my sig
|
|
\|/
vBulletin® , Copyright ©2000-2024, Jelsoft Enterprises Ltd.