barndogg

If someone could take a moment to explain torque that would be excellent?!

Thanks.

martwrxsl

Torque is a measurement of how much a force acting on an object causes that object to rotate. If you want it in car terms then look at the new audi rs6. 486lbs/ft of it from 1,000-6000 rpm. Torque is good but you need a good range of it as above. This car is torque but would love to see the gearbox!

The Rig

iTrader: (13)

The easiest way to deal with understanding torque is

when your in 5th gear and the engine is running at 2500 rpm, you plant the throttle and it picks up as if it were in 2nd gear.

martwrxsl

The audi rs6 could out accelarate a standard sti ppp from 40mph in any gear it was in! Now that is torque!

Cream

Some one once explained it to me in terms of being a boxer. BHP is how fast you hit, torque is how hard you hit. Not exactly technical I know, but kind of explains it in laymen terms

Dracoro

Torque figures themselves are largely meaningless.

Myself standing on my pushbike pushing down on the pedal am producing more torque than a Bugatti Veyron.

Many TDi's these days produce more torque than a F1 car.

Torque is a force that needs to be multiplied (through a gearbox) applied at a "rate" (i.e. revolutions in an engine).

Handily, there is a unit of measurement that tells you the above. Now if only I could remember what that unit of measurement was????

gpssti4

iTrader: (6)

Nice one

Torque is how hard the engine is trying to 'twist' - torque is a turning force hence it's measured in Newton Metres or Foot Pounds.

Power is how fast the engine can go and still 'use' the torque or 'twisting' force. If the torque is putting energy into the system (Nm of force), then power is how fast it is putting that energy to use i.e. literally power If the torque curve of an engine is flat then the power rises along with the revs. At some point the torque will drop off, typically after this you've reached 'max power' and will need to change up.

Clear as mud!

GC8

I disagree: torque is far from meaningless. Its where it is in the rev range that really matter of course; and the shape of the torque curve. BHP is far less important: its simply the relationship between torgue and engine speed...

T5NYW

iTrader: (4)

Force (lbs) x Distance(ft) = Torque(lbsft)
Force (N) x Distance(m) = Torque(Nm)

IIRC

WRX Blues

When I saw the title of this thread I thought 'at last - a definitive answer'...I am still confused

speedking

Wikipedia is your friend

The Rig

iTrader: (13)

i like that one

barndogg

LOL. I think this is one for sittign back with a spliff and thinking about!

Thanks for all the replies. I will pick my way through and get the old bonce aroudn it.

Keith Collings

iTrader: (3)

Not to mention https://www.scoobynet.com/general-te...orque-bhp.html

Guv

iTrader: (8)

Any one know the conversion from Nm of Ft/lb I've been wanting to work mine out for a while

madisonmonkey

iTrader: (4)

330 Guv

PeeVee

iTrader: (1)

1 newton meter = 0.737 562 147 28 pound foot

Dracoro

The torque figure by itself IS meaningless.

Torque X revs gives BHP. BHP is calculated FROM torque mulitplied by revs.
Gearing is then the multiplier and takes advantage of the power band. i.e. the engine produces X number of bhp at a given rpm.

When someone says car X is torquey, what they really mean is that it produces a lot of BHP low down (or in the middle of) in the rev range. People often say VTECs aren't torquey, well sit at 7000rpm in your s2000 or nsx and floor it and tell me it doesn't feel torquey!

Put it this way, if I asked you which car out of A and B below is faster (all other things being equal, i.e. weight, size etc.), what would your answer be:
A - 350ft/lb
B - 175ft/lb

And explain your answer. I bet you can't without referring to revs. It's easier to say car A produces X amount of bhp rather than saying it produces Y torques over Z rev range.

Shark Man

All I can say is 450bhp/600lbft is somewhat more fun than 450bhp/450lbft.......

Until you get a bill for the tyres, diff, gearbox, clutch.....

Dracoro

All you're really experiencing is more bhp over more of the range but not peaking over 450bhp.

Much rather have 600bhp and 450lb/ft though!!!!!

And yes, a lot more pressure on other components!!!

Shark Man

Yup.

Going back to OP's question and having a proper attempt at answering the thread's original question:

When you drive an Impreza, give it full throttle at 2000rpm in 2nd gear and wait. When it reaches around 2800rpm (TD04 ) things happen, you get pushed into the seat and accelerate at an impressive pace. This, continues, but on some standard models, one may feel a slowing of acceleration when going beyond 6000rpm

What you are feeling is the effects of torque (The application of torsional force).

What you feel as the acceleration pinning you in the seat is the sudden increase in torque caused by the turbo spinning up. Also that slowing of acceleration above 6000rpm is the drop in torque when the turbo starts to run out of puff (or the ECU pulls back the boost).

Digging up this old mostly ignored dyno(saur ) website from the good old days (shame on SDB ): Dynomite Scoobies: Subaru Impreza Turbo Rolling Road Information

One can look at various power graphs of various Imprezas.

Looking at the average dyno plot for a mostly standard classic Impreza, one sees a relative constant rate of increase in BHP over rpm across the whole rev range, whilst the torque is low at sub 2000rpm, but has a sudden rate of increase between 2500 to 3500rpm - coinciding with the "pinned in the seat" associated with the turbo spooling up. Likewise above 6000rpm some cars note a gradual drop in torque above 6000rpm where the car feels like its accelerating at a slower rate.

I don't know who Mike Molloy is, but I hope he doesn't mind me posting his graph plot for sakes of illustration: Dynomite Scoobies : Mike Molloy's car

GC8

I see your point: personally Id only ever quote 'torque@revs' though.

Simon

Henrik

iTrader: (5)

to paraphrase from the other thread:

Torque times revs times a constant equals power, and it's power (multiplied by time) that gives energy. Energy is what is required to accellerate an object (Kinetic energy = mass * speed * speed / 2).

So, we want as much power as possible to accellerate.

So, looking at the formula: "P = T*RPM*constant", we see that to have the same P, we can either have high torque at low revs, low torque at high revs or something in between for both variables.

Now, a wide high torque band, gives a wide power band, which is good for accelleration, as it's easy to keep in that RPM "band". This means that it's not as important to change gears all the time to accellerate fast (i.e. keeping in the RPM band is easier), as opposed to an engine which has a narrow power band requires more frequent gear changes. However, as long as they develop the same power over time, the two engines would accellerate the vehicle at the same speed (minus shift times etc).

SPG

The boxer comment is a good way to describe torque, another way is twisting a stubburn bottle top, in a way the more you twist the top, the more "torque" you are applying to open it.

subaruturbo_18

im going to try and explain it..



BHP is power.

Torque is turning power.

if your car had hardly any torque, but loads of power, it would barely be able to move, but if u got it moving, it would eventually pick up towards the end of the rev range (kind of like turbo lag)

if your car had loads of torque and hardly any power, your car would drive like a diesel. it would have lots of grunt and would go from stand still to moving, very very quickly, but then the second it has started moving you would have no accelerating force left and would need to change gear

MazingerZ

put it this way, if your girlfriend/wife can't open a new Mayonnaise jar is because they have not enough force to open it....

in other words, not enough TORQUE.

johnnyroper

pretty much sums up the old rover k series engine you could get a fairly decent bhp figure but torque was low,due to smaller pistons with a longer throw.so slight hill and you was down the box all the time trying to keep revs up.

Henrik

iTrader: (5)

I give up

TYP 3R

see if this helps

Howstuffworks "How Force, Power, Torque and Energy Work"

shooter007

you could also say torque is the force that will try to shear your drive shafts if your wheels dont move as landrover owners who off road know well (broken half shafts )