Another Sway Bar Question

[The WidowMaker]

you can skip the intro.. question in third paragraph.....

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

[David Pozzi]

I'm sorry I don't have time to type out a complete answer for you, but in general you want enough spring to keep the car from bottoming out on bumps and dips, also excessive front or rear dive on acceleration or braking. Once that is solved, you add-anti roll bar rate front and rear to prevent excessive roll and shift cornering load front or rear to balance out the understeer/oversteer. Shock rates have a lot to do with how much roll you will really get, just calculating it from bar rates won't allow for you throwing it into a turn, the shocks spread this force out over time.

The car's horsepower, tire size and "stick" matter as well as center of gravity height, front to rear weight balance, and suspension geometry, particularly roll center height, and anti-squat/anti-dive.

Wheel rates for springs and bars should be compared in lbs/inch at the wheel. A low rate for a front bar on a front engined car would be 50% of the wheel rate.

Springs can be selected by spring frequency, the frequency will determine the amount of suspension travel used.

You cannot just use just the front to rear bar rates for comparison without knowing a lot more about the car. Software is available to do this, either the Mitchell or Performance trends software is a good place to start, but you need a lot of basic knowledge to use it. Without it you need to copy someone's existing setup or buy a kit.

David

[The WidowMaker]

thanks for the reply...

i guess what im looking for is what determines if you have too much bar. to much proportionally on one end will make that end lose traction first, but what about to much equally on both ends? will you get less overall traction because youre lifting the inside tires?

Thanks, Tim