im my brief attempt to understand sway bars better, ive come to understand that their is a relationship btwn the bars and the springs selected coupled with numerous other parameters. while they can only be used as tuning aids, the general consensus is that they are an important part of an overall package.

with that said, my research has lead me to believe that their is a PERFECT coupling of bars for every given suspension as long as that suspension is not adjusted once the bars are installed. with our front heavy cars, this perfect coupling usually requires a higher rate in the front, and a lower rate in the rear.

now for the question.... say you have a suspension that requires an "x" rate in the front and a ".75x" in the rear. how do you solve for "x". if you keep the percentage constant with rate changes, therefore keeping a perfect neutral balanced car, what are the disadvantages to running high rates vs low rates? i would assume that too low and it will negate the bars, but what about too high?


thanks, Tim

There's really no "easy" answer. It is a tuning tool, but it's also a major part of the overall package, and getting it wrong can have a pretty big effect on the car's handling characteristics.

It's not so much the "front heavy" aspect that requires a bigger bar up front, but is more about the roll-axis. The lower your Roll-center, the stiffer the bar you'll need. On these cars stock, the FRCH is below ground, and the RRCH is something like 16-18" above ground. When you correct the camber curve, you also move the FRCH up a few inches above ground, which means you need less roll-stiffness in front, and can get by with a smaller bar, or softer springs. You also need to look at motion-ratios and mechanical advantage... the stock type rear bar on these cars works through a 22" long lever-arm, while the front is more like 12", so with the same diameter bar on each end, the front would be more effective.

thanks for the reply....

my FRCH is still at the ground (spc uppers, ats spindles, and spc or speedtech lowers) and im running a watts with a parallel 4 link on the rear. RRCH is going to be about 14 (at least to start). i do have a brief understanding of how the bars work in coorelation, but im not sure how to calculate the necessary rates. i am working on that in a few other posts and im thinking about 500 front and 300 rear splined bars. id rather run more bar and less spring for my roll stability in order to provide a little more comfort (550 front coils and 150 rear coilovers).

but for this post, i guess what im looking for is this; once you get the best bars for each end, what keeps you from increasing them or decreasing them by a proportional amount? decrease them by a proportional amount too far to the soft side and you wont have enough spring to control your roll, but you still should have a neutral handling car (maybe???). but increase them too far and what happens? as long as it was neutral what would be the harm?

thanks, Tim

Too big, and you could just as well run a solid front axle... ;)

Too much sway bar stops the wheels from moving independently over rough surfaces.

i figured that was the downside. what you said plus youll start lifting the inner tire off the ground even more.

i guess ill shoot for a rate a little higher than my 1.25" bar and run something much bigger than stock in the rear. those 150 springs wont do much of anything with a really low RRCH.

thanks, Tim