Rear Sway Bars

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wheelsport

wheelsport

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My '65 Barracuda didn't come from the factory with any sway bars and rolled quite a bit on turns, when I first bought it. I installed and AADCO 1.125" front sway bar, which helped a lot. The car still has more roll than I would like. I asked the local Barracuda guru about installing a rear sway bar. His suggestion was to leave it alone. I noticed 65 Cuda 340 that you have an AADCO sway bar on the rear of your car. Is there any input on the subject?
 
Larger torsion bars will also reduce the roll by increasing the overall stiffness of the front end.
A larger sway bar, or an 'adjustable' one set to the shortest or stiffest setting might also reduce your roll.
Increasing rear roll stiffness can help, but it will also increase the oversteer tendency of the car as well.

Front and rear should be balanced, just like with the brakes. The only way to know which is best is to test it.
There are many factors you'll need to consider including what you expect the car to be used for most frequently, even then you'll only get a good start. Testing different things will be required to find what suits you best.
 
And keep in mind that the anti-sway bar is just one piece of the suspension "system"- it will only go so far with, say, factory slant 6 torsion bars; and will not make up for any front end parts (bushings, etc.) that are in need of replacement.
 
I have one Barracuda with a front bar, and one with front & rear.

The slant six convertible has OEM soft springs and a Hellwig front sway bar. Yes, it does have some body roll, but it turns in sharply and points very predictably. I see no need for a rear bar considering its overall speed potential.

The Commando fastback has an Addco front bar with custom Heim joint end links (no bushings) and an Addco rear bar with poly bushings. It has OEM HD rear springs and big block torsion bars. Yes, it has much less body roll, but it also understeers if you can't get on the throttle (as is frequently the case on tight corners). It is however extremely stable at high speed. The tradeoff is it is much harsher on bad surfaces (the convertible is remarkably supple on the same).

You should probably consider how you are planning to drive, and what kind of roads you will encounter.
 
Since my name was mentioned, I'll respond, although I sure don't consider myself an expert. My suggestion is try the rear bar and see how you like it.

Too much rear roll stiffness can cause oversteer at the limit, but I doubt that the light Addco rear bar will be a problem, especially with your big bar up front.

People that really know what they are doing will play with springs front and rear (a torsion bar is a straight spring), not just sway bars. Then there's roll centers. bump steer and a bunch of other stuff that is all over my head. If you want to road race or autocross your car, I'm not the person to ask. I can only report that I like the way my Barracuda handles for the kind of street driving I do.
 
I have the 7/8 rear bar for mine but it's not installed yet. I put the 1 1/8 Addco bar on the front some time ago, with modified Energy suspension mounting hardware, as the Addco hardware SUCKS. It drives good, but I can tell it doesn't have a rear bar. Some say it may be too heavy a bar for the rear, but I'm gonna find out. I'll probably never push the car to its limit, so it won't matter.
 
My fastback has a 3/4" rear bar. I kind of think 7/8 would be too stiff, all other factors being equal, but diameter isn't the only criteria. The length of the arms is equally important — a thicker bar with longer arms because it mounts in a different location may have the same effective spring rate.
 
I put formula s t-bars on and a Addco front and rear sway bars along with flipping the forward leaf spring mounts . This lowered the rear about an inch . I also cranked down the t-bars down to get a 1/4” rake .
Unfortunately the Addco front sway bar connects to the strut rod and it works the bushings out in a few miles . This early design (1980’s) was a poor design , so off came the Addco front sway bar and I’ve been running like that ever since .
So flash forward to today and I’m in the process of installing a Helwig hollow front sway bar .

I have run Helwigs on my van since 74 and love them .
Over the years I’ve installed them on customers class C motorhomes and they make them handle like a car as opposed to a top heavy cabin cruiser .
 
Lots of good advice being given. Agree strongly that for top notch handling you should approach it as a system. The valiant patrol car in my avatar came with a factory rear sway bar and it oversteers (rear end loses grip and swings out trying to pass the front end, ala drifter style) nicely. I recently upgraded a '62 valiant driver with 6 leaf rear springs (4 leaf was standard) and it made such a significant difference that I'm not sure I'll add the rear bar anytime soon. Point is, as others suggested, more than one way to reduce body roll. You'll feel the difference with new rear springs or a sway bar regardless, and at lower speeds it really won't matter usually. As others have suggested it's near the adhesion limits that good or bad suspension balance becomes apparent.
 
I'm about to replace the original rear springs in my 63 Valiant convertible with six-leaf 340 springs that I've rebuilt (sandblasted the leaves, new zinc interliners, black plastic spacers and clamps, painted with black urethane). By about, I mean today, as soon as I get off my lazy rumpus. Right now it has no sway bars, but I have a factory Formula S front bar plus lower control arms with sway bar tabs that I plan to put in later. Doubt I'll run a rear sway bar on this car, but we'll see how she does and then decide.
 
wheelsport said:
My '65 Barracuda didn't come from the factory with any sway bars and rolled quite a bit on turns, when I first bought it. I installed and AADCO 1.125" front sway bar, which helped a lot. The car still has more roll than I would like. I asked the local Barracuda guru about installing a rear sway bar. His suggestion was to leave it alone. I noticed 65 Cuda 340 that you have an AADCO sway bar on the rear of your car. Is there any input on the subject?
Click to expand...
You have pictures of your anti sway bar setup? I could not get the one they sent me to fit in my 66.....to wide
 
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