pishta
I know I'm right....
I was warned, "HP sells cars, torque wins races..."
the all cross at 52xx rpm
the all cross at 52xx rpm
Is Torque King?
- Thread starter 273
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C130 Chief
Mechanical Genius
An engine only produces torque, not horsepower. Math produces horsepower. In this case HP=(TQ*RPM)/5252. A fifth grader can tell you why HP and TQ are equal at 5252 RPM.
dusterglenn
Well-Known Member
C130 has it. Torque is measured, HP is calculated.
Hersbird
Well-Known Member
You quote my post, then add a phrase in quotes that is not in my post. I didn't say "they are the same thing" I said 400 ft lbs accelerates the car with the same thrust at 10 rpm or 10 million rpm. Basically torque is the only measurable entity and hp is just a mathematical derivative that factors in rpm. I could come up with a new term called "sparkle unicorn power" based on the measurable torque value and then factors in a time value like the time it takes one of Jupiter's moons to orbit. One car may make more sparkle unicorn power but if it makes 400 foot pounds of torque it still accererates with the same force as the car that makes hardly any sparkle unicorn power.
72Dodge
Well-Known Member
Sparkle unicorn power... Isn't that what GM motors create?
67Dart273
Well-Known Member
No that is NOT what you said, so in order to remind you I will "re" quote what you SAID
Uh, whut? did you say? So maybe that is not what you MEANT but that is not what you said.
I have no idea what a sparkle unicom is so maybe you should explain that to me
451Cuda
Well-Known Member
It's the theoretical power that is added when you glue on a body kit or a huge wing.
Incorrect. Torque and horsepower are always the same at 5252. This is why the formula for horse power is HP = (RPM x TRQ)/5252. Every single time. Without fail
Thank you thank you. Sorry I duplicated your post. I should have read the whole thread first.
Fisher
Old Guy with a Cool car.
Torque is what launches and accelerates the car, Hp just carries it through to the end. The calculation for Hp is measured by Weight and mph. so the top end mph will imcrease with hp and less weight, makes sense. Your 60' and 330' get lower with TQ.
Hersbird
Well-Known Member
read your first post, you add in quotes, normally meaning that is exactly what I said, "they are the same thing". I NEVER said they are the same thing, I said they accererates at the same rate weather it is at 3000 or 6000 rpm but at 6000 you are making twice the HP.
Look at it this way Force=mass times acceleration. That means acceleration=force/mass. Torque is a measure of force and therefore creates the acceleration, the same torque creates the same acceleration at 3000 rpm as it does at 6000 rpm but because we have this other thing called horsepower stuck in our head we for some reason care that the double horsepower you are making at 6000 rpm is somehow adding to acceleration when it has nothing to do with the physics.
famous bob
mopar misfit
can`t go w/ this on all motors, look at your diesel tow truck or whatever,won`t even wind 5250 rpm`s, and ungodly torque, 800 and some advertised on some of them from the factory????????? don`t think mine are either, will look tonight if I can remember when I get home.
1967 'cuda
Dropped on Head as a Baby
Its about area under curve, and where in that curve your transmission/gearing keeps you.
for example new car with about 150hp can beat 300hp muscle car, even if muscle car has way more torque.
Why because of gearing and trans keeps that 150hp on tires right from start.
other simple example.
I had 50cc dirt bike at kid, we tuned it and it would rew 18000rpm. that thing was fast even when 0-14000rpm was useless, it made all power 14000-18000rpm.
But with good clutch operating i could keep that thing on that power curve.
But anyways torque is more fun on street car, makes tires go away
Hopefully I won't sound like a total ignoramus. I definitely am not an expert on this subject. What peelo57 says about the torque curve seems logical to me.
Because a motor is not going to be running at a steady RPM, the contour of that torque curve it seems to me would have to be a critical factor in determining the type of results you would see at a drag strip. For an example, an engine that won't produce a lot of torque until it's running 3000 to 4500 RPM should be in a car set up to take maximum advantage of where that peak torque is achieved. A radical camshaft profile combined with a rear end ratio of 3.23s would struggle on the strip until the RPM would reach the range it ran best. Through the use of gears and a stall converter (if an automatic is used) a person should be able to set a vehicle up to try to stay in that sweet spot where the most power is produced.
So if these assumptions are correct, wouldn't a guy be best off (if he wanted to be as quick as possible) designing a build to have the most torque he could get at the RPM he will be running most of the time?
And wouldn't that mean that for a street car you would want that torque maximized at a lower RPM than for a race car? A street car that will rarely see 4000 RPM would probably seem like a pooch to drive even if the engine put out gobs of power at the higher revs but put out very little in the 1500 to 2500 range.
I would think that a short track circle burner would need as broad a high torque range as you could get because it of the way it will be running. I would think that an engine designed for that use would be able to outperform (on the track) a car with an engine that produced more power - but outside of the power curve it's running half the time.
The HP and torque numbers might sound great if you're only going for bragging rights about what's on a piece of paper, but the best 'real world' result is a more complex proposition.
When I was younger I built a few engines that ran great but I didn't focus on the full package. They sounded mean as hell but I hadn't been taking advantage of what RPM they produced the best torque.
gears and I will pass you with a 100 cubes less at whatever stripe you choose.
When I say torque is a meaningless number I mean by itself it tells you nothing about and engine just like rpm. Like if I said I have two engine one made 600 lbs ft and the other one revs 10,000 rpm, first thing you would think there both serious engines but the 600 lbs ft one is a steam engine that barely turns 10 rpm and the other is a weed Wacker engine neither making more than a couple of horsepower. But if I told you there both big blocks it would give you a better idea of the performance but untill I tell you there HP you wouldn't know there true potential.
My purpose of writing this was to make people understand rpm is and equal force to torque and Torque doesn't move and or accelerate your car down the track and neither does rpm they do it together in the form of horsepower so horsepower is king.
So when a well set up 3000lb 600 hp 540 cid duster goes up against a well set up 3000lb 600 hp 340 cid duster both should be capable of the win.
My purpose of writing this was to make people understand rpm is and equal force to torque and Torque doesn't move and or accelerate your car down the track and neither does rpm they do it together in the form of horsepower so horsepower is king.
So when a well set up 3000lb 600 hp 540 cid duster goes up against a well set up 3000lb 600 hp 340 cid duster both should be capable of the win.
I say it a little differently.
Torque is the measure of how much work an engine can do.
HP is the rate that it can do that work at.
So a 1200 ft-lbs big rig diesel engine only makes 300 HP because it doesn't turn very fast, yet that engine can haul 80,000 lbs up and over the Continental Divide. It just won't do it very fast.
Contrast: an 18,000 RPM, ~700 HP F1 engine. Since it only makes ~200 ft-lbs it isn't going to be doing much work, at least not in comparison to the big rig, but that tiny, light car is sure gonna zip around!
Horsepower is a measurement of work, meaning a force applied to an object and the displacement of that object in the direction of the applied force. What does this mean? One horsepower equals 33,000 pounds-feet per minute (4,562.41 kilogram-meters), or the energy it takes to move a 330-pound (149 kg) object 100 feet (30.5 m) in one minute.
Torque is a twisting force that rotates or turns an object, like a wheel. When you use a lug wrench on a bolt, you're applying torque to it. Unlike horsepower, even if the object doesn't move, torque can still be exerted on it. Torque is measured in pounds-feet, meaning a force in pounds acting on the end of a lever measured in feet. For example, if that lug wrench is 2 feet (0.6 m) long, and you put 100 pounds (45.4 kg) of force on it, you are putting 200 pounds-feet (27.65 kg/m) of torque onto the bolt. Read How Force, Power, Torque and Energy Work for more information on torque.
Once we're able to measure torque, we can then measure horsepower. The formula is simple: Multiply torque by the engine speed (measured in rpm), then divide that by 5,252 to get the horsepower at that rpm level. In other words, to get the horsepower of a vehicle generating 350 pounds-feet of torque at 4,000 rpm, you would calculate (350 X 4,000)/5252, which equals around 267 horsepower. It comes down to this: torque measures how much work is being done and horsepower measures how fast that work is being done
http://auto.howstuffworks.com/auto-...ity/information/horsepower-versus-torque1.htm
Horsepower is the ability to do work. If you don't do "work" you can't exert horsepower.
Work is the area under the curve.
Torque is a twisting force that rotates or turns an object, like a wheel. When you use a lug wrench on a bolt, you're applying torque to it. Unlike horsepower, even if the object doesn't move, torque can still be exerted on it. Torque is measured in pounds-feet, meaning a force in pounds acting on the end of a lever measured in feet. For example, if that lug wrench is 2 feet (0.6 m) long, and you put 100 pounds (45.4 kg) of force on it, you are putting 200 pounds-feet (27.65 kg/m) of torque onto the bolt. Read How Force, Power, Torque and Energy Work for more information on torque.
Once we're able to measure torque, we can then measure horsepower. The formula is simple: Multiply torque by the engine speed (measured in rpm), then divide that by 5,252 to get the horsepower at that rpm level. In other words, to get the horsepower of a vehicle generating 350 pounds-feet of torque at 4,000 rpm, you would calculate (350 X 4,000)/5252, which equals around 267 horsepower. It comes down to this: torque measures how much work is being done and horsepower measures how fast that work is being done
http://auto.howstuffworks.com/auto-...ity/information/horsepower-versus-torque1.htm
Horsepower is the ability to do work. If you don't do "work" you can't exert horsepower.
Work is the area under the curve.
SleeperScamp
Well-Known Member
What if you put the diesel engine in the light car? I would think it would still be slower than the F1 engine... The whole mess hurts my brain...
I agree with you I was making a quick point but if you took same weight cars that turn the same E.T.s if you Dyno and figured out there torque to the ground numbers I bet they would be similar through out the run.
ProStocker273
MoPar N Jeep
Hey I know. I was just saying I've seen dyno sheets in carcraft, hotrod and other magazine where they did not cross at 5252
Then they were wrong. And I'm not bein a smartass......it's got something to do with the physics of it. I cannot explain it all. I just KNOW torque and HP always cross at 5252 RPM......and regarding the diesel thrown into the mix, yeah there are several diesels now that will rev that high. My Ford 6.0L Powerstroke would. But even if it cannot rev that high.....torque and HP WOULD be the same nonetheless. If that makes sense. I know. It's hard to comprehend. But it's a fact.
Hersbird
Well-Known Member
The torque of a torque wrench is not the same as the torque of a motor. Calling putting force on a wrench without turning it torque is somewhat incorrect. Without the movement the force applied to a wrench is called "bending moment" but is often wrongly just called torque. Torque is the force over a rotating axis, it has to be in motion to be torque. The general physics term "torque" could just be the pressure without movement, but in mechanical engineering, as in a car engine torque has to be in motion.
As I have said 3 times 100 ft-lbs accelerates the car equally at 3000 rpm as it does at 6000 rpmgeneral hough the HP is double. Doing more work, is not accelerating the car at a higher rate. Think of it as working smarter not harder.
The area under the torque curve (not HP) is the way to compare two motors. If the motor makes torque from 2000-6000 that is better then 2000-4000 but 4000-6000 is equal to 2000-4000 even though the 4000-6000 motor shows more horsepower. The 2000-6000 is better not because it will accelerate faster at any given point but that it stays in 1st gear longer multiply the torque longer, and then repeating that again in 2nd, 3rd, etc. But if the motor doesn't start making torque until 4000 rpm the time in each gear will be the same.
Hersbird
Well-Known Member
I think we are all really saying similar things but the common language leaves a lot to be desired. Instead of torque, a better term would be rotational work, and instead of horsepower rotational power, when we are talking about a rotating engine.
So take any motor, and keep it in one gear and accelerate it in a car. Measure acceleration. Does the peak acceleration occurs at peak horsepower or at peak torque? It occures at peak torque, the acceleration actually just follows the torque curve. Still you don't want to shift at peak torque because then you lose the torque multiplier from gears so the longer you can make torque (which means high horsepower) is important also, but not at the expense no bottom end torque.
So take any motor, and keep it in one gear and accelerate it in a car. Measure acceleration. Does the peak acceleration occurs at peak horsepower or at peak torque? It occures at peak torque, the acceleration actually just follows the torque curve. Still you don't want to shift at peak torque because then you lose the torque multiplier from gears so the longer you can make torque (which means high horsepower) is important also, but not at the expense no bottom end torque.
Hersbird
Well-Known Member
No way the 600hp 340 wins over a 600hp 540 because while at one point they both make the same power, the 540 makes the power over a longer period of time. Granted the 540 may make so much power early in the rpms that it can't harness it to the ground but just building a motor for peak horsepower with no regard to overall rpm horsepower is not going to give you the quickest 1/4 mile times.
What you are leaving out is gearing the 6000 rpm engine needed deeper gears to get the best quarter mile time over the 3000 rpm engine, say for eg. 6000 rpm engine needs 4:1 and the 3000 rpm needs 3:1 the 6000 engine will be putting 400 lb ft to the tires and the 3000 engine will be putting 300 lb ft to the ground. And if you ran them both with 3:1 the 6000 engine would just trade acceleration for top end speed with its more HP and RPM capabilities.
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