Sway bars ???

[razzor]

Anyone try out different sway bar setups ???
please post feedback and comments here.

How important a setup change is the sway bars ???

[KiwiBird]

They cant use swaybars overthere Shiraz!!!:D

[lowlife88]

What Does It Do?
The purpose of a sway bar is to tie the left- and right-side wheels, either front or rear, together to help control body roll. For example, as an RC car rolls through a left-hand turn, inertia forces the car to roll over on it right side. If there is no sway bar, the right side suspension compresses and the left side goes into droop, or extends. With an on-road or touring car, this overloads the right-side wheel and underutilizes the left, lowering the car's overall ability to maintain traction.
Now let's add a sway bar to the scenario. As the car rolls through the turn, the right side of the suspension compresses as before, but now instead of the left side of the suspension going into droop, the sway bar pulls the left wheel up. This limits body roll and actually causes the car to settle down through a turn. The end result is actually to lower the car's center of gravity, making it more stable.

Tuning
There are two major types of sway bars used in RC cars today: the formed-wire style and flat "blades." The wire style is more common and traditional. It's the only kind you will find on off-road cars and is also common on touring cars. It works by twisting and providing a spring action as it untwists. The blade style sway bar will usually only be found on touring cars where keeping the center of gravity as absolutely low as possible is a priority. It works by flexing, or bending the blade in a U-shape. Whichever one you use, going with a thicker bar will increase the effect of the sway bar while going with a thinner bar will reduce its effect.
Also, the type of car you drive will determine sway bar size. A lightweight car with small, light wheels can get the same effect from a small, seemingly flimsy sway bar as a much larger bar on a heavier car. Because of its relatively heavy tires and wheels, a monster truck requires a substantial sway bar to overcome the inertia in the weight of the wheels.
Depending on your setup, you may not always want to run the same size sway bar on the front and the rear. Heck, there may be times when you want to run a bar on the front and not on the rear at all. There are no hard-and-fast rules in this game, just methods for finding the setup that works best for the conditions and your driving style.

Bars and Springs
The sway bar itself does not work independently; it actually has an effect on the springs you should use. Because it ties the right and left sides of the suspension together. As one side of the suspension compresses it actually must overcome that spring and a portion of the weight of the spring on the other side as well. Exactly how much of the spring on the opposite side of the suspension is brought into play depends on the thickness, or strength, of the sway bar. If the sway bar is thin and flexible it will allow a lot of movement on one side of the suspension with very little effect on the other. If the bar is too thick or strong, it will effectively tie the two sides of the suspension together so stiffly that it essentially becomes a straight-axle suspension. The key is finding the right spot in between these two extremes.
So finding the right sway bar size is critical, but it also involves adjusting your springs to account for the bar. When adding a sway bar to a suspension system, you generally will need to soften your springs because now when one side of the suspension moves, the sway bar activates both springs.

On The Dirt
When and how you run sway bars will have a lot to do with what type of car you are driving and on what surface. In off-road racing a sway bar is more critical on monster trucks than it is on buggies or stadium trucks. This is because of the extremely high center of gravity on a monster truck. A sway bar is used to control body roll which can sometimes severely limit a truck's cornering speed. Install a sway bar large enough so that when the truck begins to roll over on one side in a turn, the bar pulls the other side of the suspension up so that the truck both squats down and levels out. The center of gravity is dramatically lowered and the ability to take a corner at speed increases.
Without a sway bar the only way to keep a truck from rolling over in the corners is to use extremely heavy springs. But doing this can cause the truck to be difficult to drive in the rough stuff and even bounce instead of absorbing impacts on landings. The beauty of a sway bar is that it has no effect on the suspension on level landings. Run the springs you need to land the jumps properly and depend on the sway bar to help you get through the turns.
One trick with dirt-track racing to remember is that a certain amount of body roll is necessary to maximize traction. Unlike on-road racing where you want to get the most traction out of all four wheels, on dirt you can take advantage of a controlled amount of body roll to really plant the outside tires in a turn. Dirt drivers also are often faster by "throttle steering," or using the throttle to kick the rear end around in the turns. Because of this you don't always want to try to achieve a totally flat ride through the turns like you would on a touring car.


The Drawbacks
The strength of a sway bar -- that it ties both side of the suspension together in varying rates--can also be its biggest weakness on rough tracks. On a smooth racing surface, the sway bar will affect a car's suspension only when you want it to--in the turns. But on a rough surface it can potentially cause more harm than good. That's because if you hit a bump or rut with one wheel, a strong sway bar can also upset the wheel on the other side of the suspension. This can cause smaller bumps that are not a problem with a plush suspension to feel much larger than they actually are if you are running a big bar. So on rough tracks, try to stick with the smaller sway bar options.

CONCLUSION
Just like your temp gauge and screwdriver set, sway bars are a tool to help you have more success with your racing. No one setting will work in every situation, and what works for one driver's style won't necessarily work for you. But now that you understand how sway bars effect your car's suspension, you should be able to use them effectively.

[manynitros]

I know razzor always advises to make or get a copy of the XRAY Set-Up Guide. I highly recommend it---it is the most thorough Set-Up Guide out there!!! If you want you can also purchase an old XB8 Instruction Manual off theBay for pretty cheap, the Set-Up Guide is in the back. This is an invaluable tool for any R/C Enthusiast. Think of it as your R/C Bible!!! Remember to make your adjustments one at a time so you can tell what is working. Good Luck...

[razzor]

Ive got the Xray manual :)
Just want to see if you guys stateside use it and what priority it has.

I am also trying to put together a offroad quick reference guide like the ones from Serpent for there onroad cars which would apply to all onroad cars.
http://i6.photobucket.com/albums/y236/razzor13bt/setupguide.jpg

My understanding at teh moment is that its more suited to faster, smoother, flowing tracks that are not rutty or have large amount of jumps etc but i may be wrong.
I have read this article http://www.rc411.com/pages/howto.php?howto=22&page=4 a few times and it sounds familiar ;)
But like anything we need to try and try and try again to understand put it into practice.

Unfortunately i havent been lucky to have as much track time as id like and with thetracl almost finish that is about to change :)

[bc24fl]

Very well said lowlife. My K8T only has a rear sway bar but I have a mugen one to put in the front. I'll put it in there when I take apart the front and rear diffs to put oil in them.

As far as the diffs, I'll try running 2,5,5 (rear, center, front respectively) and see how that goes.

[3pointX]

I just wanted to add some info about swaybars that I learned from SCCA racing. Aside from the effect they have on bodyroll and center of gravity, they also greatly affect the actual steering characteristics. Typically, bigger swaybars in the rear will induce oversteer, while smaller rear swaybars will induce understeer. For the front it's usually the opposite. Smaller swaybars will tend to increase steering, larger swaybars will typically induce push. For the most part, the same applies to RC. Since I'm getting myself ready to start racing, I've spent a ton of time learning what does what to my suspension and how everything affects how my buggy handles, and how to make the buggy match my driving style. And personally, I prefer swaybar tuning over diff tuning to get the steering characteristics I want, as changing a swaybar is WAY easier than changing diff fluids. So for me, once I find the combination of diff fluids that I like, I stick with it and tune the swaybars. I actually find that for a 4wd platform such as our buggies and truggies, a larger rear swaybar (or even a stock rear and no front), will provide overall better steering characteristics given the typical track layouts we usually see. I, like many others, like to steer with the throttle, and big front swaybars inhibit my ability to do that. However on fast, wide-open courses where you're pushing the buggy's limits, running the same size bar front and rear seems to provide a good balance. For tight technical courses with lots of switchbacks and hard corners however, I like running no front swaybar or at least having a larger rear, which makes controlled snap-oversteering much easier. I also have found that For a RWD RC platform, for those of us who have one, having a larger swaybar up front than in the rear (or having a small front with no rear) will help control throttle-oversteer, which can be a huge problem if you're putting a lot of power to the ground.