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Registered:
May 2002
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 More Torque or more Horses ?
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Thu, 12 September 2002 23:15
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Who is an Einstein here and can explain to me the difference between horesepower and torque ?
I know the general gist that more torque means u can lug trailers and shit up mountains etc but if anyone has a good explanation, it would be appreciated !
i.e. an explanation between a Type R and a 200sx would be good - I think they have similar power outputs, but the 200 has more torque (and the Type R has more torque-steer.. ok bad joke)
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Location:
Nor Calif USA
Registered:
June 2002
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Re: More Torque or more Horses ?
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Thu, 12 September 2002 23:49
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Torque is what moves the car.
Torque is what makes a car have good 60ft times
Horse power is what keeps the car accelerating.
Horse power is what makes good MPHs
If you were driving down a highway and someone is going slower
than you and you wanted to pass them.
you would give the car some gas. the engine would rev (using your
horse power) then you would passed who ever was in front of you.
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Registered:
June 2002
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Re: More Torque or more Horses ?
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Fri, 13 September 2002 00:16
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Following on from TurboRG: It the initial TORQUE of the engine that allows it to accelerate/rev.
1g-ge KE35 will set you straight if he checks this post.
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Location:
Brisbane
Registered:
May 2002
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I supported Toymods
Location:
Berowra-Sydney
Registered:
July 2002
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Re: More Torque or more Horses ?
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Fri, 13 September 2002 01:13
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i put it like this,
someone with high horse power can swing there arm very quick but when it hits you it doesn't hurt,
where someone who has torque doesn't swing there arm very quick but when it hits you it just throws you back and it hurts 
if that makes any sense 
torque gets the car moving while horsepower gets the engine to rev up quickly
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Location:
Sydney
Registered:
May 2002
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Re: More Torque or more Horses ?
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Fri, 13 September 2002 01:26
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Well.. Im all about the torque..
If you want a track car.. then torque isnt sooooo important... But round the streets.. Nothing beats it..
Ive had a GE and now a GZE in the mr2.. Very similar top end horsepower.. But torque? big difference.
For example.. The Honda S2000 puts out 186kw? the 200sx about 147kw? Ive seen both deck it.. 200sx would leave the s2000 for dead everytime..
With the high horsepower engines with no torque.. You just cant keep the revs up to keep the power up to get good times..
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Location:
Perth
Registered:
August 2002
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Re: More Torque or more Horses ?
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Fri, 13 September 2002 02:33
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Well.... Norbie has it pretty spot on....
Torque and power are very closely related.
There is a certain point in the rev range where torque goes over to Horspower.... I think it's about 5200RPMs, if memory serves me correct.
A classical example is a huge Scania truck... they put down about 1000-1200 Nm of torque, but only produce about 150-180Kw.
Yet, they haul about 20-30 Tonnes of weight, and are limited to about 100-120Km/hr, even without the weight behind them.
On the other hand... if you have the GTR putting down about 1000Hp, but only about 500Nm of torque... you will see humungous acceleration, due to hardly any weight, and top speeds of about 300Km/hr.
Moral of this..... If you want to pull something, get an engine that produces a lot of torque, such as Lancrusher, etc.
If you want a track car.... get a car with low weight, and great HP.
Corvid..... You might want to take into consideration the driver of the S2000. Give me an S2000, and I would leave the 200Sx for dead. (That is stock for stock car)
Just my 0.02 cents worth.
MIKE.
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Registered:
May 2002
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Re: More Torque or more Horses ?
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Fri, 13 September 2002 04:15
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Sums it up - ability to carry loads
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Location:
Hobart, Tas
Registered:
May 2002
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Re: More Torque or more Horses ?
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Fri, 13 September 2002 05:09
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There is a very good, long detailed explaination of torque vs HP somewhere on the net, but i can't find the link.
To add to what others have said, I'll try to explain torque a little. The 22RE in my celica doesn't have many horses at all really (116 hp, or 87 kw) but is a very torquey engine (140lb/ft, or 198nm), and makes a lot of it early on. It is torque than gets the heavy chassis going in the first place, which means it is quite 'driveable'. The celi might not have a very powerful engine, but it does take off the line fast - good low end.
You don't have to change gears all that often and can go up hills in 5th with ease. One thing I notice compared to other cars (with the same HP) is the way the engine doesn't car about going up hills at all, whereas other cars on the same hill have to shift down a gear or 2. Putting, say, a 4age in an ra65 is not recommened because, although the peak power is higher (say 100kw), they are nowhere near as torquey normally aspirated and the car would most likely be a bit of a dog to drive.
A lot of smaller engined modern cars have a much higher listed HP, but the peak torque reading is bugger all.
I also think (but not sure) that the higher rpm your peak torque is at, the more HP you have.
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Location:
Hobart, Tas
Registered:
May 2002
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Re: More Torque or more Horses ?
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Fri, 13 September 2002 05:12
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| kassma wrote on Fri, 13 September 2002 12:33 |
If you want a track car.... get a car with low weight, and great HP.
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Not entirely true. I have heard an old quote that goes soemthign like "Horsepower sells cars, torque wins motor races"
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Location:
Brisbane
Registered:
May 2002
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Re: More Torque or more Horses ?
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Fri, 13 September 2002 06:01
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| Stefan wrote on Fri, 13 September 2002 15:09 |
I also think (but not sure) that the higher rpm your peak torque is at, the more HP you have.
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Absolutely correct. In fact, power is a direct function of torque and rpm. In other words, if you know the engine's torque output and crank speed, you can calculate its power output.
That means if you want to increase the power output of your engine, you either need to increase the peak torque output (difficult without forced induction), or move the torque peak to higher rpm (easy with cams/head work etc).
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Location:
Brisbane
Registered:
May 2002
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Re: More Torque or more Horses ?
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Fri, 13 September 2002 06:03
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| Stefan wrote on Fri, 13 September 2002 15:12 |
Not entirely true. I have heard an old quote that goes soemthign like "Horsepower sells cars, torque wins motor races"
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I've heard that one many times before, but I'm afraid it's a gross simplification! Think about it, if that were true why don't you see any race cars with diesel engines?
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Location:
Newcastle
Registered:
May 2002
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Re: More Torque or more Horses ?
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Fri, 13 September 2002 06:10
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This always comes up!
Hp = Torque x Revs (using SI units)
ALL THINGS BEING EQUAL a higher hp engine will always be faster, in a given situation. Unfortunately we do not live in an ideal world. You can create more torque by changing gear ratios, but at the expense of revs.
Basically they are intimately related, even though people try and make them seem mutually exclusive. If you can produce the same torque at higher revs you get more power. What you really want to do is produce as much torque as possible through as broad a spread of revs as possible. Then gear the rest of the drivetrain to suit.
The reason they use power as a standard measuring stick for an engines performance is that it takes into account torque AND revs. Imagine moving a pile of 100 bricks. One dude can only carry 2 bricks at a time but he is really fast, the other can carry 5 at a time but he is slower. Who will win? There are a lot of variables, just like with cars, but this hopefully gives you an idea on the definitions of each.
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: More Torque or more Horses ?
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Fri, 13 September 2002 06:52
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The main argument of the people who review the S2000 is not that the engine doesn't produce the goods, its that the gearing doesn't match the engine well enough to make the most of what it has.
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Location:
Perth
Registered:
July 2002
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Re: More Torque or more Horses ?
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Fri, 13 September 2002 18:37
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Race cars with replaceable gears are usually set up so that you reach maximum revs(speed) at the end of the straights and are at max torque exiting corners. If you don't have max torque available exiting a corner you will never get to max speed.
Rolling dyno's are a classic example of the measurement of torque. The wheels apply torque to the rollers and then horsepower is calculated using the rpm values.
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Location:
Montrose, VIC
Registered:
May 2002
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Re: More Torque or more Horses ?
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Sat, 14 September 2002 12:09
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Well, to get back to the basic part of it - Horsepower equals torque (in Ft-Lbs) x RPM /5252. Sooo... a big arse Kenworth Cat Diesel still only might make a 'paltry' 600Hp, but this is done at, say, 1800rpm. A japanese GTR drag car might make 1400hp@11,500rpm, but I'd sure as hell like to see IT pulling 50 tonnes of road train! To increase the HP of an engine, you must either increase torque, increase the RPM at which the same torque is produced, or increase both. When messing with an NA engine, the usual mods such as cams, porting, etc. generally don't give a massive increase in torque, but shift the torque band up the RPM scale, allowing more HP. Fitting a turbo increases cylinder fill, which makes a bigger bang and increases torque, as well as (often) allowing the engine to breath to higher RPM, thereby giving a massive increase in HP.
The Type R produces its best power from 6000-9000RPM, whereas the nissan does so from 4000-7000RPM. If you nail the throttle on the Honda at 3000rpm, you only get so much, whereas in the Nissan you'll get a lot more excitement. Conversely, the Honda will be much happier at 8000rpm than the Nissan. This is because the Nissan produces its power at lower RPM with more torque, but is incapable of breathing well enough to rev productively to 9000rpm, whereas the Honda has a lower torque output, but can breath freely to 9000rpm thereby still producing similiar power to the Nissan.
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Location:
Montrose, VIC
Registered:
May 2002
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Re: More Torque or more Horses ?
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Sat, 14 September 2002 12:11
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Oh, one more thing - imagine if the Kenworth could rev to 11,500       
(yes that very thought makes me smile that much!)
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Location:
Montrose, VIC
Registered:
May 2002
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Re: More Torque or more Horses ?
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Sat, 14 September 2002 12:14
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Oh, and my quick calculation points that the Kenworth would be making about 3900HP, if it were producing the same torque at 11500 as at 1800
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Location:
Hobart, Tas
Registered:
May 2002
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Re: More Torque or more Horses ?
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Sat, 14 September 2002 13:49
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| Norbie wrote on Fri, 13 September 2002 16:03 |
| Stefan wrote on Fri, 13 September 2002 15:12 |
Not entirely true. I have heard an old quote that goes soemthign like "Horsepower sells cars, torque wins motor races"
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I've heard that one many times before, but I'm afraid it's a gross simplification! Think about it, if that were true why don't you see any race cars with diesel engines?
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I think maybee you could lossely read into it something like "torque curve" or useable torque or something. I think I read that in those rallys where the cars are limited to 206kw (or whatever), they work on tweaking the cars to get the widest most usable torque curve.
Anyone read the review of the 'new' Sti on autospeed.com.au? The thing is supposed to have a really crappy crazy undriveable torque curve which makes it really slow off the line.
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Location:
Brisbane
Registered:
May 2002
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Re: More Torque or more Horses ?
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Sat, 14 September 2002 23:40
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It depends on the type of racing. It's certainly true that a rally car needs a nice broad spread of torque, but at the other extreme you have drag cars that are tuned for high rpm power only. In fact most forms of racing just require gobs of power, and if that means the power is made at high rpm they simply gear it to suit!
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Location:
Finland
Registered:
June 2002
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Re: More Torque or more Horses ?
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Sun, 15 September 2002 00:45
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Norbie has it right.
It's all about keeping the engine within powerband where it works the best. We use gearing to accomplish this.
Track circuit racing. There it is possible to maintain rpm's within relatively narrow rpm window, also speed variation isn't that great. That enables engine builder to focus on engine breathing solely on this narrow rpm window. As said before, high rpm's equal high hp figures.
In rally driving (be it asphalt or gravel) the engine rpm variation is extended over a wider window. Engine has to be built to produce useable power over this required rpm window. Since engines are a summary of compromises, this will unavoidably lead into either drop in redline rpm, or at least less power delivery at redline rpm when comparing to previous engine example.
Engine suited for track work would make it not so good choise in rally driving. Despite higher hp output over the rally engine, one of the problems would be engine falling outside 'sweet operating range' when shifting to higher gear. (Rally cars have a touch wider spacing in close ratio gearing than a track car does). To what I've heard, such engine is difficult to drive. As the engine is 'stumbling' after a gear change, there is no power rush what driver is demanding. Only after waiting a moment as the engine climes up the rpm band, it will liven up suddenly, delivering all the grunt it can muster. On a gravel surface that is undesireable feature.
In this respect the old saying on torque winning races holds ground.
The answer is to decide what your rpm range requirement is and optimising the engine/drivetrain components exactly on that band.
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Location:
Melbourne
Registered:
May 2002
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Re: More Torque or more Horses ?
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Sun, 15 September 2002 02:28
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Hmm, (More Torque or more Horses ?). Sounds like a Ford 4.0L inline six to me.
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Location:
Tasmania
Registered:
May 2002
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Re: More Torque or more Horses ?
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Sun, 15 September 2002 07:41
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The question should be, More Torque or more RPM?
Horsepower is a function of both torque and rpm.
If the torque is high, you only need low rpm to achieve a set power level. If you have low torque, you need more rpm to match the same power level. If you have low torque, you can still tow stuff and overtake, but you just need to but it back a few gears. In reality, the rpm is limited.
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I supported Toymods
Location:
Berowra-Sydney
Registered:
July 2002
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Re: More Torque or more Horses ?
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Sun, 15 September 2002 08:36
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| 5KinKP60 wrote on Sun, 15 September 2002 10:45 |
Engine suited for track work would make it not so good choise in rally driving. Despite higher hp output over the rally engine, one of the problems would be engine falling outside 'sweet operating range' when shifting to higher gear. (Rally cars have a touch wider spacing in close ratio gearing than a track car does). To what I've heard, such engine is difficult to drive. As the engine is 'stumbling' after a gear change, there is no power rush what driver is demanding. Only after waiting a moment as the engine climes up the rpm band, it will liven up suddenly, delivering all the grunt it can muster. On a gravel surface that is undesireable feature.
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Here is something out of the Wheels magazine when this guy got to test drive the 206WRC car.
"The Peugeot 206 WRC certainly isn't the most brutal rally car in history.
That belonged to the up-to-450Kw Group B Audi Quattro S1's, Peugeot 205 T16's and Lancia Delta S4's that roamed the earth in 1986, before disappearing almost overnight.
But this might well be the quickest rally car of any era, particularly over the tighter events of the modern championship. Though power output from the current 2.0-litre, inlet restricted turbo engine is only around 225Kw (for a kerb weight of 1230Kg), what makes it so quick is the torque, traction, and the sheer ease of driving it.
Torque summits with 535Nm at 3,500rpm- roughly, E55 Benz numbers- with peak power at 5250rpm giving some clue to this engine's effortless, gushing grunt. Electronic anti-lag keeps it primed even on a lifted throttle by injecting fuel when the exhaust valve is open, the resultant exhaust gas charge keeping the turbo spinning."
"The acceleration hits like water from a fire-hose; not a big clumsy torrent, but a sharp jet that scoops you up and whisks you along, slurring and yawing and striding mightly over the roads surface.
You're in this white-water stream of torque, riding with it, needing only to remember to keep paddling with your hands and feet.
With all your heel-and-toe worries removed, the Pug wants to be set up into corners like a sprint Car: stabbed in the brakes with the left foot, sawed into the apex way too fast, then stomped with the right foot so everythings bucking and spinning. To make a parachute work, first you have to jump out of an aeroplane.
Changing gears is the easiest thing to do, but with everything lit up nose-in to the apex, sheer grunt hanging against centrifugal force, in those frozen moments one can forget to flip the upshift ring. Torque drives this car; grabbing the next gear regains traction and spits you back into blur-world, greedy for another cog before the road's even straightened."
[Updated on: Sun, 15 September 2002 08:39]
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Banned member
Location:
Brisbane
Registered:
May 2002
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Re: More Torque or more Horses ?
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Sun, 15 September 2002 12:03
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"Horsepower sells cars, torque wins motor races"
adding on from the comment about race cars having gobs of power and they just change the gearing to suit
i think a fair amount of torque would still be a factor as far as off the starting line and any pit stops if required...especially in drag racing
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Location:
Glebe, Sydney
Registered:
September 2002
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