Hey, just looking for some knowledge on how they work. Front and back.
Thanks.

A 'sway bar' is more correctly called an 'anti-sway' bar, and also goes by some other names.
They provide no additional load carrying capacity, but reduce lean in corners. However in doing so it also puts more load on the outside tire, and on rough pavement may reduce traction by lifting the lower wheel.

Generally add or increase the front bar first, and or increas a rear bar second.
It is generally safer to have a front tire exceed its traction than a rear tire. Because..
When front tires exceed traction the car keeps going forward,
When rear tires exceed traction the rear of the car goes forward faster than the front (fishtail and spin)

Off roaders (four wheeling) usually disconnect them if the vehicles have them. Street use, and most dirt and paved racing use them to some extent to reduce roll which helps many things.

For the How and Why, go grab one of those books recommended in the post "Where to start, A reading list"

Ideally, sway bars will be used as a tuning device once you have the proper spring rates. Throwing a big sway bar at a car that is too softly sprung will generally lead to and amplify the issues mentioned above (overloading outside tire and often lifting the inside).

Not sure how your car is set up, but if you have a stockish E body, a mild sway bar increase can help, but don't just stick a huge bar on it and expect the handling to get better.

The proper use of anti-roll bars can help handling quite a bit. Keep in mind that the stiffest end of the car tends to loose traction first. This is why Chrysler often used front bars, but seldom rear ones. When the front breaks loose first we get understeer which is generally felt to be safer, more predictable and easier to deal with than oversteer which is what happens when the rear breaks loose first. I would agree with this so long as the understeer is moderate and builds up gradually. When you really overcook a corner and the understeer comes on abruptly all bets are off.Just as a side note one of the classic definitions of the difference between understeer and oversteer among racers is that understeer scares the crap out of the driver and oversteer scares the crap out of the passenger. One of the advantages of anti-roll bars relative to simply using stiffer springs is that you can increase the roll rate considerably without loosing compliance or adversely affecting ride quality. True one wheel bumps are a bit harsher with a stiff bar, but still not bad compared to what you would experience with stiffer springs. When using stock springs on an "E" body I tend to use a stiff front bar and leave the rear bar off on 'Cudas. I would be more inclined to try a rear bar on a Challenger since they have a 2 in. longer wheelbase and bit more rear end weight. Ideally I would prefer softer rear springs and a light and adjustable rear bar so I could trim out the car's balance. Normally as stated earlier the stiffest end of the car washes out first. This would seem to contra-indicate a stiff front bar, but experience often proves otherwise. The reason is that while the stiff front bar does increase the front roll rate it also limits body roll which in turn reduces an undesirable camber [ positive ] change. This often times outweighs the effects of the increased roll rate. A rear bar can make it more difficult to put the power down early on corner exit since a bar always tends to lift the inside wheel. When it's all said and done NO ONE has all the answers, I know I certainly don't. In the end you do what works. Driving style definitely enters into this. Some people prefer a bit of understeer, others want the car to be neutral or don't mind a bit of oversteer. Personally I REALLY want the car to turn in and if there's a trace of oversteer, I'll deal with it. Of course I am not driving an Indy car going 175mph thru the "kink" at Road America either. Good luck with your project.

That 75 mph kink might not have been so bad if the bump hadn't been there to unload the suspension. I'll bet it got your attention though. I tried running a rear bar in the 'Cuda, but it was just too "busy". I can see where with your level of experience using a light rear bar on a tight circuit could be beneficial in getting some rotation. As for going flat through the "kink" at Road America, I think those guys must have to get size xxx large when shopping for athletic supporters. Not sure what the gals wear.

You can see it differently but the physics doesn't change
edit When taken too far the inside wheel will lift off the ground. This is the big bar, soft spring as described by 5spdcuda. It's not just theory, this actually happens in some instances during competition. For street most people just notice the flatter more predictable driving.

In all seriousness, at your level of interest Frankenduster, you would really enjoy any of those books on the reading list.

I'm going to add a magazine article to the reading list which involves adding a sway bar to a circle track car. It doesn't do the physics, but describes what is happening based on the data (photos, tire temps and lap times).

Yes the right rear tire is off the ground, about 1/2". I have a 22" x 32" picture of it that the photog gave me for helping him - safety car spotting during the event so he didn't get run over in case of a spinout - ..

New but stock spring rate for a Go Pack car, rear leafs. 300# per " coils up front. .750" dia rear bar and 1.130" dia front bar. 3,100 car weight, 97" wheel base. Bars made by the guru of AMC and designed for the AMX. Called Gymkana Bars.

I've got to go with Mattax on this. Weight transfer causes body roll, but body roll dosen't cause weight transfer. The main factors influencing lateral weight transfer are center of gravity height and track [ how far apart the wheels are from left to right ]. A lower the center of gravity and a wider track will reduce weight transfer. Since body roll dosen't affect weight transfer, why do we care about it? The reason is as I mentioned earlier, to prevent an undesirable camber change which reduces traction. Speed also affects weight transfer. Going slower will reduce it, but that's sort of self-defeating. Amxautox has given an excellent demonstration of both good grip, driving skill and how a rear bar on a rear drive car can make putting the power down early difficult. It's actually pretty common to see front drivers lift the inside rear in hard cornering.

The wheel lifts I was thinking of were RWD cars lifting inside front. Mostly in autocross with 'prepared' class cars that are nationally competitive. If I come across a picture I'll post it - most were in print magazines like North American Pylon and Sports Car.

Quote:

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Speed also affects weight transfer. Going slower will reduce it, but that's sort of self-defeating.

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Key words here are 'sort-of'. You touch on one of the great secrets of serious driving. Most beginers and many experienced drivers have a tough time sorting out the trade off of forward speed for cornering bite. That said, slowing down is not design goal, which of course is 5speedcuda's point. I only add this point because too too often our friends hit the track or autocross and waste time and tires ploughing on corner entry 'cause they didn't slow down enough.

I know what you're saying about lifting an inside front wheel with a rear drive car, but it takes a lot of grip to do it along with good speed. A good deal more of each in fact than what the OP is ever likely to achieve given a basically stock car. You're absolutely right about the speed part. Most racers are familiar with the truism that slow in, fast out beats fast in, slow out every time. Knowing it dosen't make easy. I know that when I need a few extra tenths I am still tempted to brake even later and harder and then I wind up coming in too hot and plowing down a few cones. Oh what the h$%^, if it was easy it wouldn't be nearly as much fun.

.Targa Challenger.

Dropping the road out from under the car is cheating.

You weren't supposed to notice that.

I think I'll put it another way for the OP. Gravity is pulling the car DOWN, cornering forces are pulling (or is that push?) the car to the outside of the turn. The forces that pull the car to the outside transfer weight pushing the car down on the suspension on the outside of the turn. The sway bar tends to lift the inside suspension toward the body. If this lift of the inside suspension is NOT enough to overcome the gravity on that side of the car you have flatter cornering. If the lift is enough to overcome gravity you have the situation where the inside tire is LIFTED off the pavement.

My understanding in the simplest terms is the following:
In a right turn, weight transfer results in the left side of the cars suspension to dive and the right side to rise. The sway bar works to equalize the reaction from one side to the other. If one side moves up or down, the other side follows. This is why, in most cases, a sway bar usually doesn't make a cars ride degrade in the way that larger torsion bars can.