As a note, with your logic, each tire would be getting 25ftlbs. This part of your statement is incorrect, the differential does not split power evenly, it splits torque evenly. Since power is the rate at which work is performed, and work is force X distance, in a limited traction situation, only one axle may be receiving all of the power. Both axles, however, will always receive 50% of the torque, whether that is translated into movement or not.

I can elaborate further if needed on that.

Also, I too prefer the empirical method: Just look at a locked vs open video, sit in an unlocked vs locked vehicle in a limited traction situation, and call it a day. I hope you didn't create this thread just to get a rise out of people as a result of your last one.

 

Traction is limited by the tires. This issue here is trasmitting the torque to the ground through the tires.

well thrust is power and power is the speed at which torque is applied, not exactly that same but you need to transmit the torque to the ground to create power.

I completely understand this.

Are you ignoring the first paragraph that says torque is split 50% to both wheels ALL THE TIME?

Your misinterpreting the paragraph your quoted. What its saying is, Thrust(amount of torque the engine can apply) is limited to maximum traction (wheel with least grip).

So with no grip you no torque. Its not that the tire with no grip get all the power, but that it limits the power the engine produces and it doesnt produce enough to move the tire with grip.

I understand the workings of a differential. ARBs video are correct but dont touch on the issue of one locker.

The offroad vids I can tell if the jeeps spinning are spinning front and rear and fully open.

Look up Force when your on Wiki next time and check out Newtons 3rd love. Force in must equal force out. Tires spinning equals a small force.

I understand how diffs work. seems likes its better than most here. I wanna know how they transmit power.

 

Your right, I forgot to divide enough I was writing it up quickly. As for the the Power, power is basically the speed the work is done. The relationship of Horserpower to Torque. We all know Torque is what makes things move.

You need Torque to do work. Torque is the force here and it sounds like you know that "Force in" must equal "Force out".

 

Go wheel your jeep. You will find out why you need them.

 

i also cant really understand what you are trying to figure out. in the quote, you pretty much nailed it. all tires front and rear recieve the same amount of power all the time. they will all turn at the same rpm.

if you have one locked axle, and one open, that unlocked 'open' axle can still differentiate power between either tire depending on which has the least amount of traction. when one tire is stuck, the other will spin faster because the spiders have to make up for the now stationary axle shaft and rotate around faster. remember this is why open diffs were invented, so one tire could spin at a different speed than the other. and thats why wheelers like lockers, it keeps all tires moving at the same rpm. i think a lot of people are mis-using the word "torque", you just need the fundamentals first.

 

No4x4yet, are you asking a question or trying to give instruction?

 

I'm going to clear something up from your last thread. You kept on saying the engine was not producing torque.

But, if the engine is producing no torque, how is it powering the accessories? That takes torque...

 

A good analogy was brought up in the previous thread. Think of it like you are cranking (winching) a boat onto its trailer, or into the boathouse. when the cable has slack (compared to one tire spinning freely in an open diff) it doesn't take your arm much torque to crank the cable in. As soon as you start to actually crank the boat, it will become much more difficult, and your arm will require more torque. When a wheel is spinning in the air with an open diff, the engine is producing very little torque, you could probably spin the wheel just as fast with your lawnmower engine. However, during all this, your engine has the ability, or potential, to produce the torque needed to move the car.

 

Maybe it's not that I'm missin using Torque, but that I should be using power. Then the speed of the wheel would be the factor that is creating the unbalance between the wheels side to side.

I'm putting out what I know so people know what I'm thinking and can explain to where I went wrong which I think I'm gettin now.

It's my engineering nature to know why and how things work. Luckily for all you "just wheel it" guys there are people like me out there that want to know so they can design and build your lockers.

I was rounding to simplify things maybe that dirt work. I thought it was a given that the engine produced enough power to over come the friction and drag forces to idle. The power required for that is relatively low as well as a constant. So I was rounding to zero since the power to move the jeep is much great and always in addition to the power to keep it at idle.

 

Exactly. So, when one wheel of an open diff is in the air, and the other is on a high-traction surface, the "force in" will only be as much as it takes to rotate the tire/wheel. A locker is there, as explained before, to ensure that the limiting torque factor is the tire with the highest traction. Thus, a locker makes you go forward where an open diff wont.

 

no, you just need to simplify. there is no 'unbalance'. the open diff balances it self out indefinitley. it may SEEM like it because one wheel is not turning, but the spider/side gears make up for that.

 

Ok, between these two paragraphs you've just showed the paradox in your logic. Think about it. The article lays out a theory and then ends with a statement declaring the limitation of that theory, which is the maximum traction of the wheel with the least grip.

This article explains it better:
[/QUOTE]The torque applied to each driving wheel is a result of the engine, transmission and drive axles applying a twisting force against the resistance of the traction at that road wheel. In lower gears and thus at lower speeds, and unless the load is exceptionally high, the drivetrain can supply as much torque as necessary, so the limiting factor becomes the traction under each wheel. It is therefore convenient to define traction as the amount of torque that can be generated between the tire and the road surface, before the wheel starts to slip. If the torque applied to one of the drive wheels exceeds the threshold of traction, then that wheel will spin, and thus ONLY provide torque at each other driven wheel limited by the sliding friction at the slipping wheel. The reduced nett traction may still be enough to propel the vehicle. Since an open differential LIMITS total torque applied to both drive wheels to the amount used by the lower traction wheel multiplied by a factor of 2, when one wheel is on a slippery surface, the TOTAL torque applied to the driving wheels may be lower than the minimum torque required for vehicle propulsion.[/QUOTE]

Notice i caped some key words for ease of explanation. Lockers are not limited by the sliding friction of a slipping wheel. Lockers do not limit the torque applied to each wheel like an open diff does. And the total torque applied to each wheel is much greater with a locked diff. So if an open diff provides a 50/50 torque split all the time then, by that same definition, a locker provides 100% torque all the time. That's why, hypothetically speaking, if you have a fully locked rig and 3 tires are without any traction but 1 tire has full traction then that rig can apply 100% of the torque supplied by the motor through that 1 tire. So it's more accurate to say a fully locked rig has 100% torque supplied to each wheel, only limited by the traction of the wheel with the MOST grip. Do you see the difference now?

 

Just to be fair to the OP. he's not saying the engine doesn't produce the torque needed to propel a vehicle. He's talking about "applied torque" via traction. Meaning that torque produced by a motor that is not transmitted into traction is useless torque or zero applied torque. I will grant you that he's not doing the best job explaining himself and sometimes he seems contradictory, but if you can wade through what might first appear nonsense you'll see that he's asking people to explain the application of torque (or power), not the generation of torque, in quantifiable terms for his sake and whoever else wants to knows sake. What can I say? I've taken the bait. Lmfao

 

This. Stop web wheeling and find a trail ride to go on. I think you need to visually see the difference between open and locked up close to fully understand it. I think you over think too much...

 

No4X4Yet statements post #17:

"I understand the workings of a differential. ARBs video are correct but dont touch on the issue of one locker."

Not in this thread, that I can find, but the previous thread, kinda on this same subject you touched on the one locked differential idea. And if I remember correctly you were asking if 1 locker would increase torque to the unlocked differential. The answer is, all other variables being equal, yes. Hang on, hear me out.

Let's go with the "one tire on ice, one on some surface with a coefficient of friction greater than 0" scenario that has been used. Open diff: tire with least amount of traction spins, minimal load on the engine, engine has no requirement to produce an equal and opposite force (increased torque). I didn't make this up, I'm not that smart. Locked diff: Same scenario, all other variables being equal One tire on ice, and one tire on other surface, not ice, are locked. Tire on other surface, not ice, increases load on engine due to friction, or as some would call, traction. Increased load equals increased demand for torque which will in turn increase torque output of the engine up to its mechanical limitations. At this point, with a 50/50 split transfer case, the transfer case is receiving some amount of torque, and transferring that torque equally to the front and rear drive shafts. So long as the demand for torque is inside the limitations of the engine, then the locked axle with one tire not on ice will, by default increase the torque supplied throughout the system. So yes a locked rear axle will in turn increase torque to your open front differential. I have not said that you will enjoy increased traction in the front with a locker in the rear. I am saying that torque in the system is increased due to the locker, all other variables remaining the same. And that can be a big step.

"So with no grip you no torque. Its not that the tire with no grip get all the power, but that it limits the power the engine produces and it doesnt produce enough to move the tire with grip" Kinda. This just means that your open diff is working like it was designed if I am understanding your statement.

Sorry for the long post, I just wanna stir the pot.