Does cranking up front torsion bars stiffen ride?

[mikesbaron]

I have a 1.5" rear shackle lift I want to install, and then crank up the front torsion bars to match. Will doing this stiffen the ride even more than it already is?

 

[TheFauxFox]

Edited for corrective action.

 

[robcarync]

No...you are not pre loading the springs. See my how to - reindex torsion bars ---> link in signature for a full explanation.

The only way to STIFFEN the torsion bar spring is to have a stronger material or a larger diameter bar.


Excerpt from my how to:

Now, a torsion bar is a spring. Most people think of a spring as a standard coil spring…you push down on it, it pushes straight back at you. A standard coil spring has a direct relationship with how far it is compressed. For instance, if you push down 1 inch, the spring pushes back with 5 pounds force. A torsion bar uses the inherent stiffness of the material to resist motion. Instead of a linear distance, a torsion bar has an angular displacement and a resulting torque. The same direct relationship applies for a torsion bar. For instance, if you twist the bar by 1 degree, the bar twists back with 5 foot pounds of torque. (Force displacement numbers are made up)


What is the point of this? When you adjust your torsion bars, you are NOT TIGHTENING the bar. The bar will have the same angular displacement because it is holding up the same amount of weight! You may crank the adjuster bolt upwards into the cross member, but the result is the lower control arm mount is pointed down, which lowers the tire and raises your ride height. This results in the same internal force in the bar, and the same angular displacement or twist in the bar. Adjusting your torsion bars will not stiffen the front suspension. The ride quality will not be changed, except for needing an alignment and the possibility of hitting the bump stops on the upper control arms (UCA).

 

[TheFauxFox]

Hmm. My mistake.
Carry on.

 

[robcarync]

No worries....just wanted to clarify to avoid confusion. I was in a hurry responding earlier...don't want to come across as short or rude.

 

[Trexterra]

On top of that I never noticed a butt difference in ride quality after cranking T bars. Upgrading to SAW T bars however...

 

[Intender]

it does not stiffen the ride, but cranking them will limit the travel. If you hit a big hole or speed bump you may notice it is harsher because it can only travel as far as your new bump stop gap.

 

[robcarync]

Further down in my how-to for re-indexing torsion bars:

Now, let’s take a look at the bump stops in the front. The UCA will hit this black rubber dome bump stop when the tire droops too low (or the frame bounces too high). Whenever you are adjusting ride height, you need to ensure that you have at least 0.5 inch gap. It is important to note that the physical gap is not what is important. The bump stop is just the easiest place to measure. The issue is with aligning the front tires. If the control arms are too low, or ride height too high, the tires can’t be properly aligned. This means that low profile bump stops can help improve tire droop, but raising the suspension further will compromise your alignment and tire wear.

Secondly, if the bump stop gap is too small, or nonexistent, the ride quality will be quite harsh. Now wait a minute you may say…The UCA contacts the bump stop when the tire droops down...doesn’t that mean the car would be off the ground for it to hit the bump stop? Not necessarily. It all goes back to the concept of a spring. When you push a spring down and let it go, it does not simply go back to the original free position. It snaps back and forth until a damping force will resist this motion. That is where your shock comes in, but no vehicle vibration will be perfectly damped; there will always be a little bit of back and forth motion. So if you hit a bump in the road, and your tire snaps upwards, the torsion bar snaps it back down. Depending on how good your shocks are, the UCA will travel below the original ride height or static position and can hit this bump stop. It may not lift the car off the ground, but it is something you can feel. I feel it on a daily basis.

Switching to Sway-Away Torsion Bars will stiffen the ride, as it either uses a stiffer material or a larger diameter bar (don't remember exactly which one).

 

[Prime]

Further down in my how-to for re-indexing torsion bars:



Switching to Sway-Away Torsion Bars will stiffen the ride, as it either uses a stiffer material or a larger diameter bar (don't remember exactly which one).

It's a stiffer material which results in a higher spring rate. So it firms up the front end.

Also, when installing the sway away bars, you want to start your indexers at 20° instead of the 40° that the OE bars call for.

 

[Joey]

I just did the 1.5" PM lift, the pic is of the X right after I finished. The ride was the same other that my drivers side seemed to react slower over bumps at highway speeds. So I cranked on it a little more to "even it out" and its good. you'll be glad you did the 1.5" PM!