HTH - hope this helps.
First off...are you asking about a rear sway bar(waste...read below) or a strut bar (stops the car from flexing).
if you're talking about the sway bar...don't waste your money. To me it's just another bolt on part where the driver experience is not increased proportionally to the value spent.
It's just another bolt on everyone thinks they "have to have." Have you pushed your car to it's handling limits? Do you know when it will begin to oversteer? Do you want to change when it over/understeers? That's when an RSB comes into play.
Otherwise...spend your money that will give you more smile factor.
your big bro.
edit...I see you already have one. To really answer your question...I'll quote the intranetz...
All of this trickery applies to a FWD car too, and since the front tires share all of the
motive AND most of lateral traction (because most of the weight is in front), all the things
that happen with big bars at either end are even more extreme. A big front bar stabilizes the body
lean more but also creates a lot more understeer, and may make the inside front tire spin madly under
power in a corner. A big rear bar can't give you back much lateral grip up front, but it can
give you back some motive traction. Basically lettting you
accelerate out of the turn, even when the front end is sliding pretty badly.
Here's a big rear bar in action on a FWD car.
Modified by vdubspeed at 9:46 PM 9-8-2009