Sway bar question

[jeremiahkellam]

I guess some of you know the problem I was having with sway bar bushings at TWS. We thought we had fixed the problem by shortening the endlinks, and the car felt good in R4. Come to find out, we had actually lost the bushings on both sides (driver and passenger) instead of just the drivers side.

First question - would having one bushing missing on each end of the sway bar (which gives about 3/4" play) be somewhat similiar to running a softer bar??

2nd question - In my best attempt to measure the angles of the existing sway bar, I found that there is 3 degrees of deviation at the ends of the bar. In other words, when the passenger side bar end is parallel to the ground, the drivers side is lower (we're talking maybe 2-3 mm). Is this normal and can it be countered by properly preloading the bar?? Or do I need a new bar??

Thanks

[Wirtz]

I have not really played with running endlinks loose in road racing except in the heavy rain and when I have too much time on my hands... Used to play with the links alot in autocross. Running extra slack in them would in effect help soften the car, at least on initial turn in. I would think once the car rolled and put load into both links, the roll rate is basically the same. I mainly remember using end link free play as a way to tune in for slaloms.

I would not think a few millimeters difference between sides is to be unexpected. Set your shim stacks for the endlinks with the car on the ground if possible, as you mention, you can get the left and right side balanced better.

Jeff

[David Love AI27]

I have not really played with running endlinks loose in road racing except in the heavy rain and when I have too much time on my hands... Used to play with the links alot in autocross. Running extra slack in them would in effect help soften the car, at least on initial turn in. I would think once the car rolled and put load into both links, the roll rate is basically the same. I mainly remember using end link free play as a way to tune in for slaloms.

I would not think a few millimeters difference between sides is to be unexpected. Set your shim stacks for the endlinks with the car on the ground if possible, as you mention, you can get the left and right side balanced better.

Jeff

What did he say???? loose links??... shimmin stacks???

[jeffburch]

...

[jeremiahkellam]

Thanks Jeff (W)

One more question - is the torsion rate of sway bars linear or progressive??

[Rsmith350]

Thanks Jeff (W)

One more question - is the torsion rate of sway bars linear or progressive??

I would think it would be linear, wouldn't the bar have to be varying diameters and and thickness across the bar to be progressive?

[jeremiahkellam]

I would think it would be progressive, but only fractionally. Think about anything you twist will eventually become harder to twist...

Ayway, I found this equation for sway bar torsional strength, first one to give correct answer gets a $1000

R = 5e6 x D^4 / (0.4244 x A^2 x L + 0.2264 B^3)

R = Torsion rate of bar
D = Bar diameter
A = Effective length of lever arm
L = Length of bar
B = Length of lever arm

note: I don't have any way of confirming answer, so you're screwed...

[edrock96GT]

I would agree on it being progressive. You could twist it a couple inches or so by hand but it would take more force to twist it much more.

Also, I don't think the 3 degrees of offset will be noticable as long as you don't preload the endlinks.

[GlennCMC70]

I would agree on it being progressive. You could twist it a couple inches or so by hand but it would take more force to twist it much more.

Also, I don't think the 3 degrees of offset will be noticable as long as you don't preload the endlinks.

your reasoning for it being progresive is not sound.
a 700lb linear spring will require 700lbs to compress 1", and 1400lbs to compress 2". its still a linear spring even though it requires more force to for each inch you compress it.
i agree the swaybar is likely progressive but not much. its likely due to the angle of the lever changing as the force is applied, but the direction of the force doesnt. thus as the angle of the lever changes the distance gets shorter between the point of force to point of rotation. a shorter lever requires more force for the same given deflection.

i'm sure RP will chime in and point out my/our errors.

[David Love AI27]

I would think it would be progressive, but only fractionally. Think about anything you twist will eventually become harder to twist...

Ayway, I found this equation for sway bar torsional strength, first one to give correct answer gets a $1000

R = 5e6 x D^4 / (0.4244 x A^2 x L + 0.2264 B^3)

R = Torsion rate of bar
D = Bar diameter
A = Effective length of lever arm
L = Length of bar
B = Length of lever arm

note: I don't have any way of confirming answer, so you're screwed...

I think you made that shit up.... RICHARD?!?!?!?