revhi

We all know the S is low in it, but what factors in an engine determine that. Is it just displacement and lack of cylinders? I do recall seeing some other 4 cyl. cars with similar torque numbers, but much less hp.

Someone explain.

papa5murf

well a lot has to do with displacement... also if you look at the cars that have similar tq and hp numbers are cars that have low redlines..... and i know there's a lot more that i don't know hahahahaa..

fknfast

VTEC

It all has to do with the way the motor is built! I head is machined like a mad man and everything is just so perfect with that motor its not even funny.

revhi

Let me use the Evo as an example, even though its turbo. It has a simliar engine size and displacement, but its torque numbers are 286 and 276 hp. A turbo S with 276 hp would not have 286 pound feet of torque.

papa5murf

ok from what i know....

the transmision has a lot to do with it....
for example what determines acceleration is the torque the car generates, not the engine's torque...... the torque that a car puts to the ground will be the engine torque multiplied by the appropriate gear ratios....

but horsepower is also a great deal of the equation.... the more horsepower the more potential torque you can create..... keep in mind i said potential.....

lower reving cars have more torque then higher reving cars (if they have the same amount of hp)

now the definition of torque is the ability to twist a shaft, regardless of how long it takes to make a revolution...... horsepower is work done over a specified period of time..... when you multiply a torque by time (revs per minute) you get horsepower....... (this is why when you look at a dyno graph the torque curve is stright thought the revs while the horsepower rises though the gears..)
there are also the internal combustion process that depends on the compresssion, design of the cylinder head, and size of a bore compaired to the length of its stroke..... all of which are effected by the weight that your moving and the gearing your using to get the power to the wheels....

so from my knowledge it pretty much... the horsepower of the car must create the amount of torque..... and i guess our cars arent' that good at converting the power to torque hehehehe... and i think this is because of vtec... with the high and low cam profiles comming into play.....

i'm probably not making any sence so imma stop now.. hhahahahahaha.

Nishant

^ thinks he is an expert at everything

i kinda know the answer but i need to figure out how to explain it

papa5murf

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Nishant &raquo;</TD></TR><TR><TD CLASS="quote">^ thinks he is an expert at everything

i kinda know the answer but i need to figure out how to explain it </TD></TR></TABLE>

i am an expert damnit. hahaha. .... i dont' really know how to explain it either hahaha

pills_PMD

you're missing a few things in the eq: hp = (tq* rpm) / 5252

and you have to factor drivetrain loss.

Mr.E.G.

another thing that effects it is the geometry of the engine. a long stroke gets more torque. and a wide bore usually equates to more horsepower.

the s2000 (2.0) has a short stroke and big bore. this was no accident.

the rsx for example has a square bore and stroke. meaning it should be fair in both repsects

Mr.E.G.

i'd be willing to bet that the evo has a longer stroke to it than the s2000.

dj elixur

its a number of things.. one major factor of torque is based on how the engines built... a larger displacement in the engine would give more torque just because you have more of an explosion going on which makes more force.. if you were driving bmws, compared with honda, you'd feel the higher torque, giving the drive the impression of more power, in this scenario, horspower would then translate for the ability to get to a top speed...

another example: in a japanese car, if u were making a right turn, u'd make it in 2nd, but in a mercedes, u can make right turn in fourth gear. power wise. technically u can make a turn if u were rolling down a hill fast enough but bear with me.. this is difficult to explain lol

think about how a car works; small explosions go off in the engine, the drivetrain then converts their power (force) into friction (torque @ the wheel) at the tire treads. *u get the basic idea of this model right?* We can all agree VTEC is what sets Acura/Honda apart from the pack. Vtec simply does away with the engine tuning compromise between high-end power and low-end torque. basically it uses three cam lobes and rocker arms for each pair of intake and exhause valves. below 46oo rpm, the outside lobes lift at a low height for a short duration of time for bursts of power(maximum torque). Between 46oo rpm n 49oo, *conditions permitting* oil pressure inside of the engine shifts the center cam lobe to the fore, causing the valves to lift higher for a longer duration of time (long whooshes of power) for maximum horsepower. this design is best for small engines because it offers low end torque and high hp w/o the stress of an added turbocharger. and then when u tack it on.. shiet.. just when most engines peter out.. u open another lung ~

WowOzYouRock

Any given car, in any given gear, will accelerate at a rate that *exactly* matches its torque curve (allowing for increased air and rolling resistance as speeds climb). Another way of saying this is that a car will accelerate hardest at its torque peak in any given gear, and will not accelerate as hard below that peak, or above it. Torque is the only thing that a driver feels, and horsepower is just sort of an esoteric measurement in that context. 300 foot pounds of torque will accelerate you just as hard at 2000 rpm as it would if you were making that torque at 4000 rpm in the same gear, yet, per the formula, the horsepower would be *double* at 4000 rpm. Therefore, horsepower isn't particularly meaningful from a driver's perspective, and the two numbers only get friendly at 5252 rpm, where horsepower and torque always come out the same.

In contrast to a torque curve (and the matching pushback into your seat), horsepower rises rapidly with rpm, especially when torque values are also climbing. Horsepower will continue to climb, however, until well past the torque peak, and will continue to rise as engine speed climbs, until the torque curve really begins to plummet, faster than engine rpm is rising. However, as I said, horsepower has nothing to do with what a driver *feels*.

if you have drag car you need to have lots of torque to launch the car and sticky tires ...

papa5murf

here's another example

if two engines have the same torque, and engine A can rev twice as high as engine B, then car A can develop twice the torque of car B by using lower gearing. this is what F1 cars do.

beyond everything. i think the tranny/gears have the most to do with how much torque you have...

dj elixur

[QUOTE=Y2K_S2K]In contrast to a torque curve (and the matching pushback into your seat), horsepower rises rapidly with rpm, especially when torque values are also climbing. Horsepower will continue to climb, however, until well past the torque peak, and will continue to rise as engine speed climbs, until the torque curve really begins to plummet, faster than engine rpm is rising. QUOTE]

in laymans terms : torque is what gets you going.. horsepower is what keeps u rolling. : ) torque will pull u out of a turn faster.. horsepower will propell u w/o losing the momentum as the torque curve peters off.. its a beautiful harmony like such when an cello takes over the bass's melody..

Francesco

simplest way i can explain it is that torque is what maintains the power through the drivetrain and gets it to the wheels.

im in Nishants boat, i know what it is, but im not sure how to type it out to explain it.

Nishant

are we discussing what torque is or what factors affect it?

dj elixur

i think the original question was *from subject line* what Determines orque.. so we've all sort of hit around the ballpark..

revhi

Very good answers. Do gears really determine torque? Say you change the gearing on a tranny, are you going to dyno more torque?

papa5murf

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by revhi &raquo;</TD></TR><TR><TD CLASS="quote">Very good answers. Do gears really determine torque? Say you change the gearing on a tranny, are you going to dyno more torque?</TD></TR></TABLE>

yes gears do a lot to determine torque... for instance read what i wrote in a post above.. but here's another example...

i stated.. that the more hp you have the more potential to create more torque....

so if two cars, have the exact same amount of hp... but one has a lower redline.. it will have more torque then the one with the higher redline....

and the other example i also used earlier..
if two engines have the same torque, but engine A can rev twice as high as engine B, then car A can develop twice the torque of car B by using lower gearing. this is what F1 cars do. (now this is because... since horsepower rises with time you'll pretty much have a higher horsepower number then car B.... therefore you will create more torque..)

papa5murf

torque is mainly what moves the car... think of the gears.....

we change our gears in our cars to get what???? faster acceleration....... faster acceleration means. more torque....

so it's like.. you have two cars side by side.... identical in every possible way.. except for one number. the torque... one has 200tq.. the other has 180tq.... the one with 200tq.. will be faster, and will accelerate faster....

revhi

What you are explaining is still the engine itself. Does the tranny or rear have anyting to do with torque? Thats what I was asking.

You said in your posts that gearing has to do with torque. I understand your explaintion, but I am asking if car A has the same engine as car B, will it dyno differently with different trannies or rears?

papa5murf

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by revhi &raquo;</TD></TR><TR><TD CLASS="quote">What you are explaining is still the engine itself. Does the tranny or rear have anyting to do with torque? Thats what I was asking.

You said in your posts that gearing has to do with torque. I understand your explaintion, but I am asking if car A has the same engine as car B, will it dyno differently with different trannies or rears?</TD></TR></TABLE>

yeah it should....

professorman

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 03s2kblue &raquo;</TD></TR><TR><TD CLASS="quote">torque is mainly what moves the car... think of the gears.....

we change our gears in our cars to get what???? faster acceleration....... faster acceleration means. more torque....

so it's like.. you have two cars side by side.... identical in every possible way.. except for one number. the torque... one has 200tq.. the other has 180tq.... the one with 200tq.. will be faster, and will accelerate faster....</TD></TR></TABLE>

Luder94

mistake***

KF_S2000

Torque is not what mainly moves the car. Torque is what moves the car PERIOD. Torque = the twisting force produced by the engine. What else is there to move a car? Put up a wind sail and wait for a good breeze???

TORQUE is what moves a car. Horsepower is simply a value based on (that's right torque) that is a way to express how the power is delivered. I'll leave it at that since HP gets off topic of the original question...

We can get into gearing also. Remember that old 10 speed bike? What happened if you started out in 10th gear from a stop? It was a bitch to get rolling no? Were your legs weaker while you were in 10th gear, but then strong when you shifted back down to 1st? Nope, your legs were doing the same amount of work the entire time (let's forget about muscle fatigue, etc).

Your legs = F20C1

Gears simply allow the twisting force from the engine to have a different mechanical advantage. That's basically what those gears on the 10 speed bike did, allow you to have optimized mechanical advantage for any given speed and load.

EDIT: Missed the most important part. What determines torque? Primarily displacement and the camshaft characteristics of the engine. There are items that will create a larger displacement volume in a smaller area such as turbos, supercharges, and even nitrous oxide. Fuel and air folks. That's it. Burning more of both of those is the only way to make power.