What do strut bars and sway bars do?

 

Strut tower bars bind the tops of your front struts together, keeping them equidistant from each other. Because of the suspension system, this prevents them from leaning to one side or the other during hard cornering, which prevents weight transfer from the body from being converted to lateral acceleration (basically, makes it corner flatter.) Sway bars do the same thing essentially, but in the back.

 

Are they useful if my car is completely stock?

 

the sway bars are more of a stiffener for the springs, and the strut bars are braces for the chassis. but yeah, they do mostly the same thing. like kappa said, they stop the car from leaning as much in corners. think of the strut bars as the top to a cardboard box. if you have a five sided box, and a six sided box, which one is stiffer? the one with a top. and yeah, they are useful, but you'll notice A LOT more difference with a good set of sway bars than you will with all of the strut braces you can fit on a car.

 

Kappa22 is a genius and if I have a daughter, I want him as my son-in-law. I learn something new everyday from that guy.

 

Haha, I've never heard that word before, I guess I learned something new today also