Shown on the picture above on Whiteline Swaybars they have 3 predrilled
holes up front and 2 predrilled holes out back for stiffness adjustability.
Now my question is which hole would be the stiffest. Thinking physically
interns of leverage many people seem to think the Inner holes would be
the stiffest. But are sway bars not suppose to reduce body roll (sway) by
forcing the outer tire up with the inner tire to level out the car? So should
you not put the endlinks on the furthest setting (outer most hole) to
increase the leverage of the bar to make it easier to lift the outer wheel?
I’m extremely confused on this whole issue here with Swaybars could
someone please straighten this all out for me and I’m sure many others.
Stabilizer bars are part of a car’s suspension system. They are sometimes also called anti-sway bars or anti-roll bars. Their purpose in life is to try to keep the car’s body from “rolling” in a sharp turn.
Think about what happens to a car in a sharp turn. If you are inside the car, you know that your body gets pulled toward the outside of the turn. The same thing is happening to all the parts of the car. So the part of the car on the outside of the turn gets pushed down toward the road and the part of the car on the inside of the turn rises up. In other words, the body of the car “rolls” 10 or 20 or 30 degrees toward the outside of the turn. If you take a turn fast enough, the tires on the inside of the turn actually rise off the road and the car flips over.
Roll is bad. It tends to put more weight on the outside tires and less weigh on the inside tires, reducing traction. It also messes up steering. What you would like is for the body of the car to remain flat through a turn so that the weight stays distributed evenly on all four tires.
A stabilizer bar tries to keep the car’s body flat by moving force from one side of the body to another. To picture how a stabilizer bar works, imagine a metal rod that is an inch or two (2 to 5 cm) in diameter. If your front tires are 5 feet (1.6 meters) apart, make the rod about 4 feet long. Attach the rod to the frame of the car in front of the front tires, but attach it with bushings in such a way that it can rotate. Now attach arms from the rod to the front suspension member on both sides.
When you go into a turn now, the front suspension member of the outside of the turn gets pushed upward. The arm of the sway bar gets pushed upward, and this applies torsion to the rod. The torsion them moves the arm at the other end of the rod, and this causes the suspension on the other side of the car to compress as well. The car’s body tends to stay flat in the turn.
If you don’t have a stabilizer bar, you tend to have a lot of trouble with body roll in a turn. If you have too much stabilizer bar, you tend to lose independence between the suspension members on both sides of the car. When one wheel hits a bump, the stabilizer bar transmits the bump to the other side of the car as well, which is not what you want. The ideal is to find a setting that reduces body roll but does not hurt the independence of the tires.
The sway bar transfers a fraction of the load by torsion. The amount transferred is determined by the deflection. The outer holes have a longer moment arm about the pivot, so deflection is greater and less is transferred.
Ok look its like this. The suspension acts on the sway bar. The sway bar torsions when opposing forces are acted upon it obvioulsy (passenger side suspension compresses, driver side extends) or if the suspension raises / lowers togehter (i.e. when you launch forward) the sway bar will not tension it will simply slide in its Dlinks.
Now assume you put a bar bolted to the chassis against the susension with the same layout as a sway bar, but it has unlimited resistance to torsion. Your suspension components would ALWAYS move together, so most likely you would have hardly any compression on corners and the inside tire would most likely raise of the ground simply from chassis flex, just like a go-kart.
The suspension applies a FORCE on the sway bar. The farther from the point of pivot the force is applied, the more leverage is created, and thus more torque applied on the swaybar. If you apply the force close to the pivot point, or basically where the bar is bent and where it torsions - the torque will be less than if placed it far away.
Higher torque on the bar = more twisting of the bar. More twisting of the bar means more opposing suspension movement, in other words more sway.
You’re thinking of it backwards, the sway bar does not apply a force on the suspension, the suspension applies a force on the sway bar. I think thats why you are confused…
But i could also be totally wrong this has always been my understanding of it…
The sway bar transfers a fraction of the load by torsion. The amount transferred is determined by the deflection. The outer holes have a longer moment arm about the pivot, so deflection is greater and less is transferred.
Right?[/quote]
Ok your post is confusing even for me.
Are you trying to say that because it has a larger deflection, that less torsion is transfered through the bar because it has a larger moment arm? Some reason that doesn’t make sense to me.
Crap I should draw up a bloody beam situation and do the calculations. But I don’t have time. If you want me to in 2 weeks we can talk. Stupid exams :x
That’s what I thought originally but would the suspension not have to
work harder to transfer the energy though the bar with it being closer
to the pivot point? Like why do we use a 2 foot bar instead of a 1 foot
bar to torque down a bolt? Because with longer leverage it makes it
easier to transfer energy. This is why I am so confused. Is not the
point of a sway bar to transfer the energy being pushed up on the
suspension by the inner wheel to the outer wheel to balance out the car?
I already told you about this Adam, it’s about leverage.
So the innermost holes are stiffer.
As shown below by my awesome ASCII art, the holes at #1 have more stiffness.
3 2 1 =================== 1 2 3
o o o =================== o o o
Take a piece of metal tube. Put your hand to the outermost edge and try
to bend the bar. It’s easier right? Now if you put your hand closer to the
middle, it’s a lot harder/stiffer.
Right, I’m NOT disagreeing with that at all man, my point is
the whole idea of the sway bar is to transfer energy from the inner tire to
the outer tire upon cornering right? So why make it harder to do so by
putting it on the inner holes? I must be missing something here…
Anti-sway AKA Anti-roll. You don’t want the car to roll right? So keep it stiff.
Now you are probablly wondering why Whiteline would offer the option to
let you go with more flex then. Well, perhaps a little flex is good
sometimes. I guess it would depend on the setup of the vehicle.
Whatever the case, I’m keeping mine on full stiffness. I’ll get used to it.
BTW, I talked to a shop about heim-joints and they will carry something
in a few weeks. And I was told it’d be about $20 for the joints so I’ll
look into that for a cheaper alternative then PDM’s $65USD ($100CAD
shipped almost).
Put the OEM bar and the Whiteline bar on top of each other. This is what
you will see. The whiteline only offers you the option to run less stiffness.
That is all.
o ============ o <-- OEM
o o o ============ o o o <-- Whiteline
like i said before man, the suspension puts force on the bar, and the bar resists the movement. Ur thinking about it backwards.
If there was NO bar, the suspension could move as it wish. If it was unlimited stiffness the suspension wouldn’t move. The farthest out hole is the softest because the suspension applies the most leverage on the sway bar.
the closer hole requires more force than the outer hole… dont think of it as the sway bar acting on the suspension think of it as the suspension acting on the sway bar!!!
Another thing, the stiffness settings will let you adjust to understeer or
oversteer depending on setup.
For example, if you keep it on softest up front (outer most holes on the
front bar) and stiffest in the rear, I believe you will induce more oversteer.
“When you go into a turn now, the front suspension member of the outside of the turn gets pushed upward. The arm of the sway bar gets pushed upward, and this applies torsion to the rod. The torsion them moves the arm at the other end of the rod, and this causes the suspension on the other side of the car to compress as well. The car’s body tends to stay flat in the turn.”
Thus would you not want to make it easier to push the inner suspension
components upward via a larger leverage point? (Outer Most Holes?)
