GT350 1/4 mile

[CANTWN4LSN]

Nope. But waiting for this car takes us into some very off topic areas.

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[derpington]

Horsepower IS torque LOL.

No, it really isn't. They can be derived from one another using time, but they are definitely NOT the same thing. I don't understand why you can't grasp this.

You can't use horsepower in calculating a vehicle's track time. You need to use ((torque @ certain RPM after gear multiplication)/(tire radius))/mass.

Torque at RPM is horsepower, as we've already established. Horsepower at the wheels already takes into consideration gearing. Mass, although technically distinct from weight, can be used interchangeably in this scenario. So how is what you're saying different than horsepower at the wheels and weight?

Just being given "you have 150 horsepower and your vehicle is 3300 lbs, what is your acceleration?" can't be found. At what RPM is that horsepower at? That gives the force of the acceleration, as 150 horsepower at 100 RPM and 150 horsepower at 5000 RPM will accelerate a car at drastically different rates.

No, 150 hp at 100 RPM will accelerate a car of the same weight the exact same as 150 hp at 5000 RPM. This is like saying a ton of lead weighs more than a ton of feathers.

 

[cosmo]

No, it really isn't. They can be derived from one another using time, but they are definitely NOT the same thing. I don't understand why you can't grasp this.

I implied "is" in that horsepower is nothing more than a derivative of torque at a given RPM. By definition, HP is power. Power is the rate of doing work. Work is a force applied over a distance. Torque is a force. Torque being applied over a period of time by a moving vehicle is power. Why can't you grasp that torque is relevant to the discussion of acceleration?

Torque at RPM is horsepower, as we've already established. Horsepower at the wheels already takes into consideration gearing. Mass, although technically distinct from weight, can be used interchangeably in this scenario. So how is what you're saying different than horsepower at the wheels and weight?

Because horsepower at different points of RPM propels a car differently. Due to torque. You said "all you need is horsepower and weight". You don't have RPM, it can't be done. The only way you can calculate it is by doing derivatives of horsepower, which as I covered, the derivative of horsepower is torque.

No, 150 hp at 100 RPM will accelerate a car of the same weight the exact same as 150 hp at 5000 RPM. This is like saying a ton of lead weighs more than a ton of feathers.

You have an Ecoboost Mustang. Punch it at 5000 and 6000. The vehicle dynos with about the same horsepower at those points. You'll feel a difference in acceleration due to the loss of about 50 ft-lbs of torque. You have an accelerometer in the car, test it. If you can feel that, you would definitely feel the difference of 150 HP at 100 RPM and 5000 RPM.

 

[mustang_guy]

Nope. But waiting for this car takes us into some very off topic areas.

Thats because us car people are an awkward, weird bunch. Some of us lack social skills too. Its awesome. Its like an asburger convention.

 

[stanglife]

Asperger.

 

[Nataphen]

Asparagus.

 

[derpington]

I implied "is" in that horsepower is nothing more than a derivative of torque at a given RPM. By definition, HP is power. Power is the rate of doing work. Work is a force applied over a distance. Torque is a force. Torque being applied over a period of time by a moving vehicle is power. Why can't you grasp that torque is relevant to the discussion of acceleration?

It is the "at a given RPM" that matters, though. This is a very important distinction to make, because it changes what is being measured. If I were to say I traveled 9 miles that means one thing. If I were to say I traveled 9 miles per second, that means an entirely different thing. So saying something produces 150 ft/lbs of torque and saying something produces 150 ft/lbs of torque per second are, likewise, very different things that measure different qualities. The first doesn't necessary mean anything moved at all. This is why torque is meaningless to acceleration.

Because horsepower at different points of RPM propels a car differently. Due to torque. You said "all you need is horsepower and weight". You don't have RPM, it can't be done. The only way you can calculate it is by doing derivatives of horsepower, which as I covered, the derivative of horsepower is torque.

You have an Ecoboost Mustang. Punch it at 5000 and 6000. The vehicle dynos with about the same horsepower at those points. You'll feel a difference in acceleration due to the loss of about 50 ft-lbs of torque. You have an accelerometer in the car, test it. If you can feel that, you would definitely feel the difference of 150 HP at 100 RPM and 5000 RPM.

These statements show a fundamental misunderstanding of what horsepower is. Time has already been factored into horsepower, so RPM is irrelevant. 150 hp is 150 hp regardless of the RPM. One horsepower is the amount of power that moves 550 lbs. one foot in one second. So if you know the weight, you know the horsepower, and you know the distance, you can calculate the time.

 

[mustang_guy]

Asperger.

:lol: nah its asburgers

 

[CM581978]

assburgers

 

[cosmo]

These statements show a fundamental misunderstanding of what horsepower is. Time has already been factored into horsepower, so RPM is irrelevant. 150 hp is 150 hp regardless of the RPM. One horsepower is the amount of power that moves 550 lbs. one foot in one second. So if you know the weight, you know the horsepower, and you know the distance, you can calculate the time.

You're too far into the literal definition of the meaning of "horsepower" and how it was derived. 150 HP at 100 RPM and 5000 RPM will accelerate a mass differently. Horsepower is broken down into (Force times N)/5252.

Rearranging gives: Force = 5252 * (HP/N) as we confirmed time and time again. Going by what you're saying, that 150 HP is 150HP at different Ns (100 and 5000), that leads your Force to be 7878 lbf and 157 lbf. Different. We are talking acceleration. A different force will give a different acceleration assuming weight is the same. a=F/m. F is bigger at 100 RPM, it will give a larger acceleration.

 

[Hack]

No, torque at the wheels does not accelerate a car. Torque does not accelerate a car, period. This isn't what it is a measure of. Horsepower enables a car to accelerate, as it is a measure of power, not force. .

Actually torque at the wheel will accelerate a vehicle. Period. I can't believe you can't see that. You must be thinking about a formula in a book rather than considering the real world.

Just think for a minute or two and you might be able to figure it out. Seriously.

Get a torque wrench. Tighten a nut to 100 ft/lbs of torque and maintain this pressure. You're applying more force to the nut than a sport bike's engine is outputting, but you're not accelerating at all.

If I apply 100 ft/lbs to a wheel nut, the sport bike will roll forward and fall down unless something else is applying a force to keep it from moving and something is holding the bike up preventing it from falling. In fact, even without trying it I can state that I won't be able to apply 100 ft/lbs to the nut, because the bike will accelerate away from me too quickly if I try to do that. Can you really have never tried to torque a nut before?

 

[GT P-TREE]

This thread is giving me assburgers

 

[cosmo]

This thread is giving me assburgers

Go away then, cartman.

Derpington, you're obviously educated. But it just didn't click. The horsepower definition varies, just like a Pascal. 1 Pascal is defined as 1 Newton per 1 square meter. However, 1 Pascal can also be 0.5 Newton per 2 square meters. If someone says "there's 1 Pascal of pressure", that only tells some of the story. You don't know across how many square meters that Pascal is applied. Just as you don't know how much force is really in 150 HP WITHOUT knowing the RPM.

:cheers:

 

[derpington]

You're too far into the literal definition of the meaning of "horsepower" and how it was derived.

What does this mean? What metaphorical definition of horsepower should I be using that makes your solution correct?

Rearranging gives: Force = 5252 * (HP/N) as we confirmed time and time again. Going by what you're saying, that 150 HP is 150HP at different Ns (100 and 5000), that leads your Force to be 7878 lbf and 157 lbf. Different. We are talking acceleration. A different force will give a different acceleration assuming weight is the same. a=F/m. F is bigger at 100 RPM, it will give a larger acceleration.

No, it won't. Once again, this is like saying a ton of lead weighs more than a ton of feathers. They both weigh 2,000 lbs, there is just a higher volume of feathers. Since horsepower is the ability to move weight distance over time, this should be obvious.

Actually torque at the wheel will accelerate a vehicle. Period. I can't believe you can't see that. You must be thinking about a formula in a book rather than considering the real world.

Ah, yes, a formula in a book that was just made up and has no bearing on the real world and not at all based on empirical evidence of hundreds of years of scientific study. I must be thinking of that.

If I apply 100 ft/lbs to a wheel nut, the sport bike will roll forward and fall down unless something else is applying a force to keep it from moving and something is holding the bike up preventing it from falling. In fact, even without trying it I can state that I won't be able to apply 100 ft/lbs to the nut, because the bike will accelerate away from me too quickly if I try to do that. Can you really have never tried to torque a nut before?

I mean, I have torqued probably hundreds of lugnuts to ~100 ft./lbs and never once have I had the vehicle accelerate away from me even a single time. In fact, they stop moving and I can apply 100 ft./lbs of torque to them with no movement at all. Strange that the torque I am apply doesn't cause the vehicle to take off. It's almost as if torque isn't a measurement of power at all and does not cause a vehicle to move.

Go away then, cartman.

Derpington, you're obviously educated. But it just didn't click. The horsepower definition varies, just like a Pascal. 1 Pascal is defined as 1 Newton per 1 square meter. However, 1 Pascal can also be 0.5 Newton per 2 square meters. If someone says "there's 1 Pascal of pressure", that only tells some of the story. You don't know across how many square meters that Pascal is applied. Just as you don't know how much force is really in 150 HP WITHOUT knowing the RPM.

:cheers:

It clicked just fine. The definition of one imperial horsepower does not vary, nor does the definition of one Pascal. One horsepower is the amount of power required to move 550 lbs one foot in one second. Sure you can say that you can move 1100 lbs 6 inches in one second, but that is still the same amount of power. The definition doesn't vary, but you can vary the factors in the equation. Same with a Pascal.

Note that your example of a Pascal lacking the amount of area over which it is applied is a false equivalence to horsepower. Horsepower already includes time in the definition, which is why RPM is irrelevant. Your Pascal example, however, does a great job of telling why torque doesn't tell you accelerate since it doesn't take into consideration time.

 

[nametoshowothers]

Wow soooooo much wrong in this whole argument of torque force power and acceleration

Surprising there have been a few correct statements but mostly not

For the sanity of all here probably best not to read this thread. Just fair warning to the unsuspecting


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