sway bar tech?

[Stuart]

Can somebothy explain me the working of a sway bar? What is the best bar thickness for a super convertible? How does it affect over/understeer? Maybe a article on the web? Every help/reply welcome.

[Rob]

Oversimplification:

Bigger bar in the rear: induce oversteer (back comes around)

Bigger bar in the front: induce understeer (car plows straight)

When you take a left corner, weight is transferred to the right of the car. The suspension on the right side compresses, and the suspension on the left side 'raises'. An anti sway bar basically works against this by tieing (sp?) those 2 points together..
When the suspension 'travels' the contact patch of the tire changes. In an extreme situation you will lift your left rear tire.
Although this looks cool, it means you now only have traction on 3 wheels in stead of 2. Sway bars try to work against this by reducing bodyroll..


Well, at least that's how I understand it....haven't finished my book yet ;-)

Rob.

[pure55vw]

The sway (anti-roll) bar is simply a convenient way to adjust the weight transfer front-to-rear. On some cars, of course, (including SB's), it also serves as a suspension locating link. The stiffer bar generally improves handling at the expense of ride quality (due to the increase in single wheel bump rate). The "best" bar to use is a matter of personal taste and desires in ride/handling within the limitations of the type of car it's on. That is, you don't want "too much bar" on the rear of a rear-engine car, for example.

[Supa Ninja]

I put a 3/4 " bar on the rear with stock 3/4" on my Super ( was waiting for a order from Topline). I incredible amount of oversteer was the result. Then the following weekend I installed the 7/8" front swaybar and that balanced everything out. I hardly got any oversteer, even on slippery surfaces I can barely induce a lil oversteer. Also the body roll is greatly reduced. I don't think a sway bar has anything to do with weight transfer from Front to rear, that is controlled by the spring rate of the rear torsion bars.

Nick

[Aurumen]

Sway bars do control the weight transfer front to rear...or at least in effect, they do. What they really do is adjust which part of the car gets more traction. With too big a bar in the front than in the rear, more weight and more traction goes over the rear wheels allowing the rear tires to bite more than the front, giving understeer. With too big a bar in the rear, the front tires bite more giving the "loose" or oversteer condition where the rear end tries to pass up the front end. From the factory, most non-racing inspired cars are built with some understeer, because it gives you a nice front end squeel when you go around a corner too fast telling you to slow down.

Nick

[pure55vw]

The right idea, Aurumen, but it's actually the opposite. A bigger bar on the front makes the front transfer more weight, which can "overload" the front tires (especially the outside corner), causing them to "slip" more, in turn making the car "plow" or "push" (understeer). The same thing can happen on the rear with a bigger bar there, made worse by the extra load of the rear-engine bias. A possibly dangerous situation which supa ninja discovered when the 3/4 rear bar was installed with a stock front bar ("..incredible amount of oversteer.."). Installing the 7/8 bar re-shifted some weight transfer to the front, with a (probable) decrease in overall roll angle of the car. The OEM's believe that the "average" driver can control a heavy understeer condition much better than a heavy oversteer, so, like you say, most cars are built that way from the factory.

[Aurumen]

I actually wrote my reply with the opposite on there...then switched it cuz it didn't make sense at the time. I stand corrected

Nick