Yavapai County Sheriff, Verde Search and Rescue

edit: they are magnetic only go on when I'm on a call...

 

the county cant affort to buy the sheriff dept something newer than a 1gen dakota!?

 

Your physics is correct but your thinking is wrong.

F is a constant, the weight resting on the torsion bar, k is constant, you havent changed the spring rate, so x is constant because when rotating one end of the bar without holding the other end in a fixed position there is NO angular displacement. Both ends will rotate the same amount, that's what causes the free end of the bar to give you lift.

Look at the equation, F (weight of the truck on the end of the bar) is constant, k is constant (you havent changed the spring rate), therefor x must be constant also.

Maybe you could devise an experiment and see for yourself.

 

LOL I can't afford a new truck at this time, Search and Rescue here is a totaly volunteer organization.

I bought this truck new, it now has over 266,000 miles on it. A lot of that off road!

 

Ahh. I read that wrong. I read it as that was a sheriff truck that did search and rescue. the personal vehicle volunteer S/R makes more sense.

 

Just one last question for you... why do you think the back of the torsion bar is not fixed?

How a Torsion Bar Works
A torsion bar works by resisting the torque placed on it. When one end of the torsion bar is affixed to an object that cannot be moved, the other end of the bar is twisted, thus causing torque to build up. When this happens, the torsion bar is resistant to the torque and will quickly go back to its starting position once the torque is removed. In general, the object that cannot be moved is usually a frame. If there is not any force applied to the torsion bar, it will stay at the same position until force is applied.

 

I'm getting tired of this conversation. F=kx : x=F/k : k=F/x As long as you keep any two of those factors constant the third must remain constant also.


The rear of the torsion bar is fixed. When you rotate the rear of the bar to a different position you have changed the fixed position of the rear, the front of the torsion will follow it exactly because it is not fixed and F has not changed. By rotating the rear of bar have you added any weight on the front of it, no. So for the second time, considering the equation someone happened to provided: F=kx, F weight of the truck on the torsion bar is fixed, k, spring rate is fixed so x must not have changed either. There is no more tension on the bar no matter what height the F end is resting at. There is equal force upward on the rear of the bar as there is downward force on the forward end of the bar. Rotating the rear of the bar will only rotate the front of the bar the same amount as the rear, there will not be any more Force on either end of the bar.


OK, think of a coil spring, if you put a block underneath the bottom of a coil spring will that put more force on the spring? NO, why? because you have not increased F, have you increased the spring rate? NO, Why ? because it is fixed at the time of manufacture. All you have done is raise the complete assembly. The only way to change x is to change F or k.

Say F is a 2000# mass 2 feet off the ground, if you raise that 2000# mass to 3 feet off the ground is it any more or less massive? NO! Sure it took energy to raise the mass but the mass didn't change value, it's still a 2000# downward force. It is acutally a little less than a 2000# force of downward because it is farther form the center of mass of the earth.

You say you are an engineering student, take this discussion to your professor.

Now getting away from theory and into the real world. Since you have raised the suspension 2" it can flex two more inches, it will be able to generate more x to cause an increase in F, therefore generating more F at the rear of the torsion bar to help prevent the suspension from bottoming out. That might seem like a harsher ride if you drive so aggressivly as to get close to bottoming out. But it will not be harsher during normal driving conditions.

 

Calm down, just a debate. I honestly didn't read past this. The fixed position of the rear DOESN'T MOVE. If it moved, there would be no pressure on the front at all. You did prove there all constant if there is movement by both front and back because of course... if both moved the force would be the same, but it doesn't move. Actually the spring constant formula isn't relevant if the back moves.

My apologies to who started this thread for cloggin it up

 

Hey, no problem, I enjoy a livley debate. Especially when I'm right LOL.


The spring formula is totaly relevant to the incorect statment someone made and many people believe that tweaking your torsion bars will give you a harsher ride. If a person understands physics the formula proves that your ride will remain the same under normal conditions.

It's the aftermarket manufactureres that are perpetuating that false statement in order to sell thier own products.

 

wow versadog is way overthinking the torsion bar, when a torsion bar is cranked, it isnt being moved down, itis being twisted down thus creating a downward thrust which will make a stiffer ride. i have two trucks with torsion bars, an 05 4x4 chevy silverado, and a 1990 4x4 dakota, i have new keys on the chevy. they just have a slightly tweaked slot so that you can go tighter thus creating more lift and riding stiffer I have notice a difference in the keys, the chevy keys opperate soley on the concept of being twisted, the dakota's operate by being twisted, and pushed downward, thus the key of a dakota isnt at a fixed height. There is the huge hump on the key of a dakota. The round hump pushes the bar down, and the bolt threw the key twists the torsion bar like a wrench. this twisting moves the hump like a wedge against the rail, and the twisting action is also applied threw the t-bar. the ride does get a little stiffer, but not as much as other torsion key designs. it may be physics, but it is also common sense. just crawl under your truck and look, quit typing things into your calculator