Is it really worth getting anti sway bars? I have ground control coilovers and eibach kyb agx adjustible shocks/struts, toe steer eliminators, front strut tower brace. Would I notice any difference with anti sway bars? I was thinking about the racing beat ones.

 

I would, I did rather, every little thing helps to eliminate or minimize body roll.

 

Anti-Sway Bars: A Primer

How do sway bars work, and how can you use them to tune your car’s suspension? Most performance people know that stiffer rear sway bars reduce the understeering tendencies of a vehicle, but if you ask them exactly why this is they generally draw a blank. Usually they know the results, but not the reasons behind chassis tuning. This article is intended to answer those questions as well as give readers a better understanding of what goes on in your suspension when you take a corner. First, let's get an understanding of what lateral weight transfer is, because this will help you understand exactly how sway bars work to tune the balance of the chassis.



Lateral weight transfer is a function of three things:



-overall weight of car

-height of the Cg (center of gravity)

-track width (this is the distance between the vertical centerlines of each tire on an axle, and many times track width is different on each axle)



So the first thing to notice here is that spring rate IS NOT a primary determinate in how much weight is transferred laterally on a car for a given amount of steering input. This is something many people have a hard time swallowing, but nevertheless it is true. All the springs primarily do is determine how much the suspension will compress or expand due to this weight transfer.





BODY ROLL

One thing that's really important to understand is the difference between body roll and weight transfer. Although weight transfer is not a function of suspension setup, body roll very much is. Basically, how much the body rolls when going into a corner is originally a function of suspension design, and it only resisted through spring rates and anti-sway bars. This revolves around the concepts of suspension roll centers and the roll axis, which are beyond the scope of this article but important to just be basically aware of. So remember that body roll and weight transfer are not directly related, you can have weight transfer without body roll if things are set up just so.





So why is body roll bad? Two reasons:

#1- it screws up the camber angle of the tires to the road, plus throws off other suspension settings

#2- it unsettles the driver



Next, you need to know that the principle way you control body roll is through spring rates. And here's where we encounter the problem of not being able to change the static spring rates between cornering maneuvers and just going straight. To show a quick example of this:

- Say the amount of body roll during a corner is 10 degrees for a spring rate of 500 lbs. If you wanted to halve this amount of roll, you would need to roughly double the spring rate to accomplish it. Now we already know that limiting body roll can improve handling (depending on circumstances and suspension setup), but running a spring that stiff will cause the car to be so bouncy that the tire will rarely be in good contact with the ground, unless the road is perfectly smooth. So how can we selectively increase spring rates only under cornering so that our straight line stability & tire to road contact is not compromised by really stiff springs? The sway bar is the answer.



Now it should be stated here what sway bars essentially do, even though I know you may already know this. What a sway bar does is counteract the action of body roll during cornering by transferring spring rate from the inside wheel to the outside wheel in a corner. This means that you don't actually get any added spring rate; you just subtract it from one side and add it to the other. This has the ultimate effect of transferring load from the inside tire to the outside, which has the visual effect of compressing the suspension on the inside of the turn and expanding the suspension on the outside of the turn (thus limiting body roll). This is good mainly because it smoothes the speed of weight transfer during quick transitions and also limits the camber change experienced at the corners of the car through suspension travel. And of course, using this concept one can dial in the amount of total loading on the outside tire by varying the effectiveness of the sway bar (stiffer bars equal more transfer). And the beauty of all this is that it mostly only occurs during cornering, so our straight line spring rates are not affected. The other thing Ok, so hopefully now you all understand this concept. This is the most important part though, so if anything is still fuzzy read this again until you get it

 

that was the long answer.... the short answer is Yes... if you drive the car hard, you'll notice that you have stiffer bars.

 

[quote name='GreyGT-C' date='Apr 23 2005, 06:19 PM']Anti-Sway Bars: A Primer

How do sway bars work, and how can you use them to tune your car’s suspension? Most performance people know that stiffer rear sway bars reduce the understeering tendencies of a vehicle, but if you ask them exactly why this is they generally draw a blank. Usually they know the results, but not the reasons behind chassis tuning. This article is intended to answer those questions as well as give readers a better understanding of what goes on in your suspension when you take a corner. First, let's get an understanding of what lateral weight transfer is, because this will help you understand exactly how sway bars work to tune the balance of the chassis.



Lateral weight transfer is a function of three things:



-overall weight of car

-height of the Cg (center of gravity)

-track width (this is the distance between the vertical centerlines of each tire on an axle, and many times track width is different on each axle)



So the first thing to notice here is that spring rate IS NOT a primary determinate in how much weight is transferred laterally on a car for a given amount of steering input. This is something many people have a hard time swallowing, but nevertheless it is true. All the springs primarily do is determine how much the suspension will compress or expand due to this weight transfer.

BODY ROLL

One thing that's really important to understand is the difference between body roll and weight transfer. Although weight transfer is not a function of suspension setup, body roll very much is. Basically, how much the body rolls when going into a corner is originally a function of suspension design, and it only resisted through spring rates and anti-sway bars. This revolves around the concepts of suspension roll centers and the roll axis, which are beyond the scope of this article but important to just be basically aware of. So remember that body roll and weight transfer are not directly related, you can have weight transfer without body roll if things are set up just so.

So why is body roll bad? Two reasons:

#1- it screws up the camber angle of the tires to the road, plus throws off other suspension settings

#2- it unsettles the driver



Next, you need to know that the principle way you control body roll is through spring rates. And here's where we encounter the problem of not being able to change the static spring rates between cornering maneuvers and just going straight. To show a quick example of this:

- Say the amount of body roll during a corner is 10 degrees for a spring rate of 500 lbs. If you wanted to halve this amount of roll, you would need to roughly double the spring rate to accomplish it. Now we already know that limiting body roll can improve handling (depending on circumstances and suspension setup), but running a spring that stiff will cause the car to be so bouncy that the tire will rarely be in good contact with the ground, unless the road is perfectly smooth. So how can we selectively increase spring rates only under cornering so that our straight line stability & tire to road contact is not compromised by really stiff springs? The sway bar is the answer.



Now it should be stated here what sway bars essentially do, even though I know you may already know this. What a sway bar does is counteract the action of body roll during cornering by transferring spring rate from the inside wheel to the outside wheel in a corner. This means that you don't actually get any added spring rate; you just subtract it from one side and add it to the other. This has the ultimate effect of transferring load from the inside tire to the outside, which has the visual effect of compressing the suspension on the inside of the turn and expanding the suspension on the outside of the turn (thus limiting body roll). This is good mainly because it smoothes the speed of weight transfer during quick transitions and also limits the camber change experienced at the corners of the car through suspension travel. And of course, using this concept one can dial in the amount of total loading on the outside tire by varying the effectiveness of the sway bar (stiffer bars equal more transfer). And the beauty of all this is that it mostly only occurs during cornering, so our straight line spring rates are not affected. The other thing Ok, so hopefully now you all understand this concept. This is the most important part though, so if anything is still fuzzy read this again until you get it


[/quote]





yeah, thats what i said