Owned

So the big discusion is Hp vs Torque. I tell ya, the guys in the F-body club really like me know..I've done pissed off one of the moderators twice now cuz I really don't think he knows what he's talkin bout. Anywho, I'm not knockin his numbers but at the wheels he's got 409hp and 380ft/lbs of torque. So I, being me, said something about boasting HP instead of torque, while every one else was in awe because he had some ass at the wheels. I wasn't even being disrespectfull. So this other dude, the pissed off guy, starts to bust my balls about it. So I told him, tq wins races and hp gets it in the top end. I told him that if he had 400hp and 350tq and I had 350hp and 400tq then I'd own him and he'd be my bitch all the way down the track. So yeah, he called me out. He's got a stock LS1 with cold air, throttle body and a 75 shot of nos, so with nos he's got 420hp and 410tq at the wheels. He thinks he's gonna take me to town. 383 12.2:1 compression 520hp and 535tq at the wheels. :owned:

lol, so in his heavier fourth gen, with roughly 100 less hp AND torque, he thinks hes gonna win???? interesting....

Yeah, I'm thinking of asking him if he want's to throw in pink slips. :bigthumb:

what kinda ace do you suppose he has up his sleeve??? or is he just dumb?

He's one of them guys that thinks he knows more than I do because he's older than me. I've been building engines and cars for going on 8 years now, and he had some one else do his work for him..yeah the bolt ons.. go figure.

young wiper snapers, no respect i tell ya, well back when i was a youngin, we swept floors just to LOOK at fast cars, now these young guns, buildin cars, goin fast, beatin me, great googaly moogaly

Oh, and the first time I pissed him off, some one asked about modding the TBI 305, and you know me..I told him how to do it. Well this joker came on bashing me saying that the 305 can't be a performance engine no matter what you did to it. So I told him about my super L03, told him it would beet a any stock 2002 SS and even some moderatly modified ones as well. Well this didn't go over well with him...needless to say he tried ot make me a laughing stock. :nutkick:

dont' ya love it

eh what cha gonna do, i cant really say anything, remember our first few conversations lol

well maybe I'll just have to earn there respect like I've earned yours and every one elses on here.

Is that your car in your sig. If so I deff. think your car would beat him. LOL, your cars doing a wheelie!! LOL His can't... :evillol: OH , and if so...really cool car :smokin:

I wish it was mine.

where are these ppl at, lemmie at em

I just love looking at the tire

That back tire is pretty trippy... :iceslolan

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There's been a certain amount of discussion, in this and other files, about the concepts of horsepower and torque, how they relate to each other, and how they apply in terms of automobile performance. I have observed that, although nearly everyone participating has a passion for automobiles, there is a huge variance in knowledge. It's clear that a bunch of folks have strong opinions (about this topic, and other things), but that has generally led to more heat than light, if you get my drift :-). I've posted a subset of this note in another string, but felt it deserved to be dealt with as a separate topic. This is meant to be a primer on the subject, which may lead to serious discussion that fleshes out this and other subtopics that will inevitably need to be addressed.
OK. Here's the deal, in moderately plain english.


Force, Work and Time
If you have a one pound weight bolted to the floor, and try to lift it with one pound of force (or 10, or 50 pounds), you will have applied force and exerted energy, but no work will have been done. If you unbolt the weight, and apply a force sufficient to lift the weight one foot, then one foot pound of work will have been done. If that event takes a minute to accomplish, then you will be doing work at the rate of one foot pound per minute. If it takes one second to accomplish the task, then work will be done at the rate of 60 foot pounds per minute, and so on.
In order to apply these measurements to automobiles and their performance (whether you're speaking of torque, horsepower, newton meters, watts, or any other terms), you need to address the three variables of force, work and time.

Awhile back, a gentleman by the name of Watt (the same gent who did all that neat stuff with steam engines) made some observations, and concluded that the average horse of the time could lift a 550 pound weight one foot in one second, thereby performing work at the rate of 550 foot pounds per second, or 33,000 foot pounds per minute, for an eight hour shift, more or less. He then published those observations, and stated that 33,000 foot pounds per minute of work was equivalent to the power of one horse, or, one horsepower.

Everybody else said OK. :-)

For purposes of this discussion, we need to measure units of force from rotating objects such as crankshafts, so we'll use terms which define a *twisting* force, such as foot pounds of torque. A foot pound of torque is the twisting force necessary to support a one pound weight on a weightless horizontal bar, one foot from the fulcrum.

Now, it's important to understand that nobody on the planet ever actually measures horsepower from a running engine. What we actually measure (on a dynomometer) is torque, expressed in foot pounds (in the U.S.), and then we *calculate* actual horsepower by converting the twisting force of torque into the work units of horsepower.

Visualize that one pound weight we mentioned, one foot from the fulcrum on its weightless bar. If we rotate that weight for one full revolution against a one pound resistance, we have moved it a total of 6.2832 feet (Pi * a two foot circle), and, incidently, we have done 6.2832 foot pounds of work.

OK. Remember Watt? He said that 33,000 foot pounds of work per minute was equivalent to one horsepower. If we divide the 6.2832 foot pounds of work we've done per revolution of that weight into 33,000 foot pounds, we come up with the fact that one foot pound of torque at 5252 rpm is equal to 33,000 foot pounds per minute of work, and is the equivalent of one horsepower. If we only move that weight at the rate of 2626 rpm, it's the equivalent of 1/2 horsepower (16,500 foot pounds per minute), and so on. Therefore, the following formula applies for calculating horsepower from a torque measurement:


Torque * RPM

Horsepower = ------------

5252


This is not a debatable item. It's the way it's done. Period.
The Case For Torque
Now, what does all this mean in carland?
First of all, from a driver's perspective, torque, to use the vernacular, RULES :-). 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*.

You don't believe all this?

Fine. Take your non turbo car (turbo lag muddles the results) to its torque peak in first gear, and punch it. Notice the belt in the back? Now take it to the power peak, and punch it. Notice that the belt in the back is a bit weaker? Fine. Can we go on, now? :-)


The Case For Horsepower
OK. If torque is so all-fired important, why do we care about horsepower?
Because (to quote a friend), "It is better to make torque at high rpm than at low rpm, because you can take advantage of *gearing*.

For an extreme example of this, I'll leave carland for a moment, and describe a waterwheel I got to watch awhile ago. This was a pretty massive wheel (built a couple of hundred years ago), rotating lazily on a shaft which was connected to the works inside a flour mill. Working some things out from what the people in the mill said, I was able to determine that the wheel typically generated about 2600(!) foot pounds of torque. I had clocked its speed, and determined that it was rotating at about 12 rpm. If we hooked that wheel to, say, the drivewheels of a car, that car would go from zero to twelve rpm in a flash, and the waterwheel would hardly notice :-).

On the other hand, twelve rpm of the drivewheels is around one mph for the average car, and, in order to go faster, we'd need to gear it up. To get to 60 mph would require gearing the wheel up enough so that it would be effectively making a little over 43 foot pounds of torque at the output, which is not only a relatively small amount, it's less than what the average car would need in order to actually get to 60. Applying the conversion formula gives us the facts on this. Twelve times twenty six hundred, over five thousand two hundred fifty two gives us:

6 HP.

Oops. Now we see the rest of the story. While it's clearly true that the water wheel can exert a *bunch* of force, its *power* (ability to do work over time) is severely limited.


At The Dragstrip
OK. Back to carland, and some examples of how horsepower makes a major difference in how fast a car can accelerate, in spite of what torque on your backside tells you :-).
A very good example would be to compare the current LT1 Corvette with the last of the L98 Vettes, built in 1991. Figures as follows:


Engine Peak HP @ RPM Peak Torque @ RPM

------ ------------- -----------------

L98 250 @ 4000 340 @ 3200

LT1 300 @ 5000 340 @ 3600


The cars are geared identically, and car weights are within a few pounds, so it's a good comparison.
First, each car will push you back in the seat (the fun factor) with the same authority - at least at or near peak torque in each gear. One will tend to *feel* about as fast as the other to the driver, but the LT1 will actually be significantly faster than the L98, even though it won't pull any harder. If we mess about with the formula, we can begin to discover exactly *why* the LT1 is faster. Here's another slice at that formula:


Horsepower * 5252

Torque = -----------------

RPM


If we plug some numbers in, we can see that the L98 is making 328 foot pounds of torque at its power peak (250 hp @ 4000), and we can infer that it cannot be making any more than 263 pound feet of torque at 5000 rpm, or it would be making more than 250 hp at that engine speed, and would be so rated. In actuality, the L98 is probably making no more than around 210 pound feet or so at 5000 rpm, and anybody who owns one would shift it at around 46-4700 rpm, because more torque is available at the drive wheels in the next gear at that point.
On the other hand, the LT1 is fairly happy making 315 pound feet at 5000 rpm, and is happy right up to its mid 5s redline.

So, in a drag race, the cars would launch more or less together. The L98 might have a slight advantage due to its peak torque occuring a little earlier in the rev range, but that is debatable, since the LT1 has a wider, flatter curve (again pretty much by definition, looking at the figures). From somewhere in the mid range and up, however, the LT1 would begin to pull away. Where the L98 has to shift to second (and throw away torque multiplication for speed), the LT1 still has around another 1000 rpm to go in first, and thus begins to widen its lead, more and more as the speeds climb. As long as the revs are high, the LT1, by definition, has an advantage.

Another example would be the LT1 against the ZR-1. Same deal, only in reverse. The ZR-1 actually pulls a little harder than the LT1, although its torque advantage is softened somewhat by its extra weight. The real advantage, however, is that the ZR-1 has another 1500 rpm in hand at the point where the LT1 has to shift.

There are numerous examples of this phenomenon. The Integra GS-R, for instance, is faster than the garden variety Integra, not because it pulls particularly harder (it doesn't), but because it pulls *longer*. It doesn't feel particularly faster, but it is.

A final example of this requires your imagination. Figure that we can tweak an LT1 engine so that it still makes peak torque of 340 foot pounds at 3600 rpm, but, instead of the curve dropping off to 315 pound feet at 5000, we extend the torque curve so much that it doesn't fall off to 315 pound feet until 15000 rpm. OK, so we'd need to have virtually all the moving parts made out of unobtanium :-), and some sort of turbocharging on demand that would make enough high-rpm boost to keep the curve from falling, but hey, bear with me.

If you raced a stock LT1 with this car, they would launch together, but, somewhere around the 60 foot point, the stocker would begin to fade, and would have to grab second gear shortly thereafter. Not long after that, you'd see in your mirror that the stocker has grabbed third, and not too long after that, it would get fourth, but you'd wouldn't be able to see that due to the distance between you as you crossed the line, *still in first gear*, and pulling like crazy.

I've got a computer simulation that models an LT1 Vette in a quarter mile pass, and it predicts a 13.38 second ET, at 104.5 mph. That's pretty close (actually a tiny bit conservative) to what a stock LT1 can do at 100% air density at a high traction drag strip, being powershifted. However, our modified car, while belting the driver in the back no harder than the stocker (at peak torque) does an 11.96, at 135.1 mph, all in first gear, of course. It doesn't pull any harder, but it sure as hell pulls longer :-). It's also making *900* hp, at 15,000 rpm.

Of course, folks who are knowledgeable about drag racing are now openly snickering, because they've read the preceeding paragraph, and it occurs to them that any self respecting car that can get to 135 mph in a quarter mile will just naturally be doing this in less than ten seconds. Of course that's true, but I remind these same folks that any self-respecting engine that propels a Vette into the nines is also making a whole bunch more than 340 foot pounds of torque.

That does bring up another point, though. Essentially, a more "real" Corvette running 135 mph in a quarter mile (maybe a mega big block) might be making 700-800 foot pounds of torque, and thus it would pull a whole bunch harder than my paper tiger would. It would need slicks and other modifications in order to turn that torque into forward motion, but it would also get from here to way over there a bunch quicker.

On the other hand, as long as we're making quarter mile passes with fantasy engines, if we put a 10.35:1 final-drive gear (3.45 is stock) in our fantasy LT1, with slicks and other chassis mods, we'd be in the nines just as easily as the big block would, and thus save face :-). The mechanical advantage of such a nonsensical rear gear would allow our combination to pull just as hard as the big block, plus we'd get to do all that gear banging and such that real racers do, and finish in fourth gear, as God intends. :-)

The only modification to the preceeding paragraph would be the polar moments of inertia (flywheel effect) argument brought about by such a stiff rear gear, and that argument is outside of the scope of this already massive document. Another time, maybe, if you can stand it :-).


At The Bonneville Salt Flats
Looking at top speed, horsepower wins again, in the sense that making more torque at high rpm means you can use a stiffer gear for any given car speed, and thus have more effective torque *at the drive wheels*.
Finally, operating at the power peak means you are doing the absolute best you can at any given car speed, measuring torque at the drive wheels. I know I said that acceleration follows the torque curve in any given gear, but if you factor in gearing vs car speed, the power peak is *it*. An example, yet again, of the LT1 Vette will illustrate this. If you take it up to its torque peak (3600 rpm) in a gear, it will generate some level of torque (340 foot pounds times whatever overall gearing) at the drive wheels, which is the best it will do in that gear (meaning, that's where it is pulling hardest in that gear).

However, if you re-gear the car so it is operating at the power peak (5000 rpm) *at the same car speed*, it will deliver more torque to the drive wheels, because you'll need to gear it up by nearly 39% (5000/3600), while engine torque has only dropped by a little over 7% (315/340). You'll net a 29% gain in drive wheel torque at the power peak vs the torque peak, at a given car speed.

Any other rpm (other than the power peak) at a given car speed will net you a lower torque value at the drive wheels. This would be true of any car on the planet, so, theoretical "best" top speed will always occur when a given vehicle is operating at its power peak.

"Modernizing" The 18th Century
OK. For the final-final point (Really. I Promise.), what if we ditched that water wheel, and bolted an LT1 in its place? Now, no LT1 is going to be making over 2600 foot pounds of torque (except possibly for a single, glorious instant, running on nitromethane), but, assuming we needed 12 rpm for an input to the mill, we could run the LT1 at 5000 rpm (where it's making 315 foot pounds of torque), and gear it down to a 12 rpm output. Result? We'd have over *131,000* foot pounds of torque to play with. We could probably twist the whole flour mill around the input shaft, if we needed to :-).

The Only Thing You Really Need to Know
Repeat after me. "It is better to make torque at high rpm than at low rpm, because you can take advantage of *gearing*." :-)

wow......... i think thats the longest post ive ever seen on AF.... and it actually SAYS something.... *Bows* you must have no life lol jk :)

excuse me while i get my reading glasses @_@

DAMNIT!! I read through that whole thing, and FORCED my brain to understand it cause I thought I could try and help someone... But I agree with you, BUT I have seen dyno's where the torque and hp were different at 5252, dont ask me why but I know I saw a couple on this web-site, not sure which forum. Great write up!

Dude you got way to much time on your hands.

I thought we were talkin about blowers here.

yea thats pretty loooooooong

not as long as my.......nevermind.

ya sure about that

thats not what.... nevermind

i'll post a pic for ya

So I was right, right?? :confused:

nice pic ridge.

So I was right, right?? :confused:

yup, i would say so

nice pic ridge.

thanks, i thought it was pretty cool considering it was takin at my local track

Ok, I'm glad someone started this thread because theres something I just can't understand. I've heard it said before that torque equals acceleration, basically, and that a car with more torque will win over a car with less torque. So why is the third gen Iroc rated at 345 lbs., more than an lt1 z28 (right?) but the Iroc stock would get destroyed by the stock lt1? What if the Iroc had a 6 speed and the same gears as the newer z28, I still don't think it would beat it. Know what I'm sayin?

BTW... that really long post was plagerized because I've read it before on the web!!! nice try though.
Torque=distance*force
force=mass*acceleration
so in this way torque relates to acceleration

Ok, I'm glad someone started this thread because theres something I just can't understand. I've heard it said before that torque equals acceleration, basically, and that a car with more torque will win over a car with less torque. So why is the third gen Iroc rated at 345 lbs., more than an lt1 z28 (right?) but the Iroc stock would get destroyed by the stock lt1? What if the Iroc had a 6 speed and the same gears as the newer z28, I still don't think it would beat it. Know what I'm sayin?

well torque isn't everything, it makes a big difference in launch but it won't win all races. take a look at the hummer H2 it has about 400 ftlbs of torque and about 100hp (not exact numbers) and it goes from 0-60 in about 20 seconds. an engine needs high hp and torque to be fast, in my opinion though, torque is more important. *mmmmm....* torque

You have to look at how long the torque curve is, plus look at his gearing and huge fucking wheels.

BTW... that really long post was plagerized because I've read it before on the web!!! nice try though.
Torque=distance*force
force=mass*acceleration
so in this way torque relates to acceleration

Hey I'm no fool, I understand what I posted. I type with one finger and wrench with two hands so there's no way I'd have the time to type this whole passage. It damn sure thoroughly answers the question askd, especially for those that care to learn!

true true.

Ok, I'm just sayin, what you did was plagerism, is it not

you dont have to "type" the whole thing when you can copy and paste in 2 clicks :wink: And i hate to be picky but that long article had almost perfect english/typing, and a message you obviously typed i see atleast 2 grammar errors in 2 sentences. I mean dont take it the wrong way, I dont care. Just sayin

Ya. disregard my previous post because im a jackass.

It's not plagerism because he's not trying to publish it. He just found some good info and passed it on to us.

Alright, maybe I misuderstood, but there was no intro saying, "look what I found on the web" it was sort of just, "I have the answer" which to me is it not taking those words for your own... it's a matter of perspective. He posted it as if he just wrote it, and I was just shocked because I've read that same article on the Web before, and even at the end no references to a source, I mean, when I have something from the net I want you guys to read, I just post the link, isn't that what everyone does. So to waste the time copying and pasting, I dunno, seemed to me like he was tryin to pass it off.

No matter, either way the info got out there. And I really don't blame him, I'm not in school anymore so I probably wouldn't have put a ref either..

It doesn't matter, I was merely pointing it out because I thought he was trying to pass it off as his own, I mean, if I posted to you, 1992RS, about some rebuild for the 305, you might think I was posting because I had done this rebuild or something, and then you realize you read the same article on the web word for word about the rebuild, what would you think then, you'd prolly post and say, yo WTF, I thought you were telling me something you did, not copying and pasting an article from the web.

Hey heres an idea how about just posting the site where this info came from. That way if you wanna read it you can, but if your like me and just got bored as hell reading it you don't have to. A post this long just isn't neccessary.

Hey heres an idea how about just posting the site where this info came from. That way if you wanna read it you can, but if your like me and just got bored as hell reading it you don't have to. A post this long just isn't neccessary.
Did it take to much of your time away from buffin your Mustang tool to scrool past it?

Here comes the hate. No as a matter of fact my stang stays buffed.

lol, hate is everywhere through out this forum, i think its unnessary as long as your tryin to help someone, you aint gotta hate on someone tryin to help, even is the person drives a ford or whatever else

Here comes the hate. No as a matter of fact my stang stays buffed.
Sorry, just thought it was no big deal. I only wanted to pass on some info that pertained to the question. I didn't feel I deserved getting my balls broke over and over again. No hate intended.

Its all about american muscle for me. Doesn't matter whether its Chevy or Ford.