Sway bars

[Removed]

I didn't know much about these, so searching on the US sites, I found this interesting bit of info:

 

"Sway bars connect from wheel-to-wheel, underneath the car. They act as a means for the car to transfer weight (via laws of physics) from one wheel, to the other.

 

Consider the 4 wheels on a RX-8 (50/50 distribution), and at resting state, lets say hypothetically there is 1000 lbs on each wheel. (Keep in mind this doesn't mean the car weighs 4000 lbs, it just means the effective weight on each wheel is 1000 lbs.)

 

When you turn, accelerate, brake, and so forth, that weight "rolls" from one part of the car, to the other. When the weight being applied to each wheel changes, the amount of available traction also changes... less weight means less tractions, more weight means more traction.

 

So, lets say our RX-8 is at the apex of a turn (not accelerating, not braking) such that there are 1500 lbs on each inside wheel (front & rear) and 500 lbs on each outside wheel (front & rear). This means that there is a good deal of body roll going on; 500 lbs transferred from the outside of the car, to the inside. The loss of weight on the outside can cause those wheels to lose traction, which can result in undesireable effects, such as oversteer or understeer.

 

If the RX-8 is equipped with (better, stiffer) sway bars, the weight transfer will be lessened. On the turn we described above, the effective weight on the inside wheels may be 1100, and the outside wheels may be 700.

 

You may be wondering "wtf happened to the other 200 lbs?" The sway bars actually "absorb" some of the weight through physics equations I don't understand. Effectively, while they are equalizing the weight distribution, some weight is "lost" or "absorbed."

 

This is why when you put a very stiff sway bar on the rear, you tend to INCREASE oversteer. When you put a very stuff sway bar on the front, you INCREASE understeer. The wheels are more likely to lose traction because there is less effective weight on them, because the bar is very stiff.

 

Conversely, having NO sway bars will result in alot of lateral body roll, which can cause loss of traction on both ends, and a less controllable car.

 

The key is finding a happy balance. As you know, you can counter understeer with oversteer, and vice versa. But reducing your front traction (with a front sway bar) doesn't increase your rear traction, it just makes the handling of the car more stable, more predictable, and more BALANCED.

 

The fundamental point is to have an even balance that suits your driving style. If you like breaking the back end loose, bolt on the biggest rear sway bar you can find, and take off the front.

 

Like any mod, its good to "tune" it... get an adjustable sway bar set and try it out on various setting and see what you like. On the Z, which is pretty balanced as it is, I'd recommend either a front bar only, or an adjustable set where you can set them both the same, or set the front tighter. Again, it comes down to your driving style and what you like."