rear sway bar ??

[69chargerR/T]

I have a stock front sway bar on my 69 charger. I want to put a rear sway bar on it, does it matter what size rear bar I put on it. There are lots of rear sway bars out there and everyone seems to have different size rear bars, 7/8,3/4,and 1". I was looking at the summit rear sway bar but its 1", is this bar to big to use with the stock front sway bar ??

[69chargerR/T]

This is the sway bar I was looking to get. Anyone use one of these.
http://www.summitracing.com/parts/SUM-720231/

[HPP]

Yes, the size of the rear bar does matter because you want to create a balanced feel when compared to the front.
In general, I've tended to use larger than stock front bars to complement a rear bar as a result of this balance, but the combination of t-bars and leafs can impact this as well.

The mounting method of the bar will impact the applied rate as well. In my analysis I've found that a .75 diameter frame hung, stock style bar like that offered by Firm Feel will produce around 95# of force at the wheels. By comparison, a 1.0" bar like you've pictured mounts significantly differently yet despite it significant increase in size, only produces 130# of force at the wheels because of the mounting methods.

I have used bars like the one you have pictured. They do work, but I have also heard of some people having problems with the mounting points tearing at the frame rails. Since I tend to reinforce any mounts I add, I've never had this problem. I would recommend maybe shopping around a few websites before taking the plunge as I have seen these used for $100 and less.

You might also consider the Hotchkis rear bar set up.  While more expensive, they also offer several adjustable end link points. Each point changes the applied force of the bar which can help you in achieving a more balanced feel with the stock front bar.

[NorwayCharger]

http://www.hotchkis.net/search.html?Make=13&Model=1251&SubmitForm=Search

[69chargerR/T]

http://www.hotchkis.net/search.html?Make=13&Model=1251&SubmitForm=Search

The hotchis bars are nice but a lot of $$$ My car is just a cruiser that I drive on weekends, I live in the country that does have alot of curves. I just want the car to handle a little better than it does now. The summit bar looks like its adjustable,with dog bone type links. It looks just like the hellwig rear bar. The hellwig rear bar is one I'm all so looking at, its 7/8" and adjustable and the price is more in my range I have been looking around at sway bars there is not a lot of choice's for chargers

[Just 6T9 CHGR]

I am running an Addco rear sway bar.  got it a few years ago on clearance from Summit for like $65 bux.   Definitely a budget bar but I do feel a difference.     Got the black powdercoated one & painted everything black for a "stealth" look

[Mike DC]

  
It's easy to mistakenly give these cars too much rear swaybar action because of the regular springs' placements.  



Notice that the front torsion bars (not the front swaybar) are acting on the chassis way inwards from the wheels themselves.  Whereas the rear leaf springs are set opposite, with the spring eyes & shackles mounted way out at the sides of the chassis just inside of the wheels.  This setup creates a built-in native bias in the chassis just from the 4 wheel springs alone.  

So theoretically, even if the front & rear wheel springs had identical rates, and if there were no swaybars mounted on either end, the car would still have some amount of stiffer rear swaybar feel to it.    
     

[HPP]

True, but even with that, the t-bar is exactly at the pivot point for the front control arm so its spring rate to motion ratio is 1:1. That means if you have a 100# t-bar, it applies exactly 100# of force at the wheel. By comparison, the rear suspension, even with the springs far outboard, still has a motion ratio that softens the spring rate when applied to the wheel. I forget the exact ratio, I think it is around 1.75:1, so that 160# spring is only applying 100# of force at the wheel. Yes, I suppose youcould set it all up with identical wheel rates, but that would lead to a trunk load of other issues aside form have a tail happy car.

Sway bars have similar types of motion ratios with their attachement as well.  Front bars tend to mount further outboard and apply more rate, rear bars tend to mount further inboard and apply less rate.

[lisiecki1]

Great information in this thread  keep it coming!

[Blakcharger440]

I think Firmfeel offers the rear sway bar that mounts above the rear axle like the factory offered,has beefier frame mounts and is priced less than the Hotchkiss one?

[NorwayCharger]

I think Firmfeel offers the rear sway bar that mounts above the rear axle like the factory offered,has beefier frame mounts and is priced less than the Hotchkiss one?

http://www.firmfeel.com/swaybars_a.htm

[mjolson]

True, but even with that, the t-bar is exactly at the pivot point for the front control arm so its spring rate to motion ratio is 1:1. That means if you have a 100# t-bar, it applies exactly 100# of force at the wheel. 

Thinking this through...  The lower control arm acts as a lever (althought with the fulcrum at the end of the lever) on the torsion bar.  So using the anology of a long breaker bar, wouldn't the length of the control arm impact the effective spring rate?  Said another way, if the control arm length were doubled wouldn't you expect the spring rate to drop?

[HPP]

Yes. The 1:1 rating on mopar torsion bars is assuming using the OEM spec lower control arm. So if you bolt A body lower arms (which are like 5/8" longer than B body arms) in to you B body, your 250# t-bar is now something slightly less.

Following that line of thought, if you use a wheel with substantial positive offset, you will also reduce the applied wheel rate compared to using a zero offset wheel.

[Mike DC]

 
Yeah, the LCA affects the rate of the spring at the wheel with its length. 


The bottom line is that the rate of deflection at the wheel is always the number that really matters.  Whether it's for leaves, torsion bars, coils, swaybars, shocks, suspension bushings, chassis flex, or anything else.