I picked up the Cobb Tuning Sway bar kit (cheap) and I am thinking of installing them on my 05 STi.

I was told to do otherwise because of handling issues in rain, snow, clovers, etc.

I'm not a speed demon racer or rally guy so the car isn't used for those purposes. I'm just looking for input and personal experience about these sway bars and what can I expect during everyday normal driving conditions.

 

A rear sway bar will make your back end a little looser. Therefore, if you are unacustomed to the extra movement in back, driving in rain, snow, etc can be a little trickier. Basically, by upgrading the rear sway bar, you'll reduce some of the inherient understeer in the car. Under dangerous situtations, you may have a tendancy to spin out more. If you know how to control that, then its fine. If you don't, you can end up in a world of pain.

If the kit contains a front and rear bar, then the car will corner much flatter at high speeds, and you won't notice as much body roll. Again, the handling characteristics are different then stock, and can cause problems (though, the back end won't have as much of a tendancy to step out on you).

I personally don't think there is a need for upgraded sway bars, unless you are racing the car.

 

I put the perrin bars on my 04 sti, wanted cobb but settled for perrin, and have definately noticed a difference. I don't really race mine either but is fun to take corners faster than others on the road.

 

What is the diameter of the stock bars VS the Cobb? I see the cobb is 25mm and tubular not solid... Are the factory bars solid? Anyone have trouble with the bars binding on tight turns?

 

what if you upgraded the front and the rear

 

Stock sedan WRX rear anti-sway bar is 20mm. I think the WRX wagon is 19mm. The bars are solid, at least on the '02 model. No, I've never experienced 'binding' with the stock anti-sway bar and I'm not sure what you mean by that.

Both front and rear anti-sway bars can be upgraded. Most folks just get the rear bar but some people like to try to balance the front ends along with the adjustable rear. With a thicker front bar, which once again makes the front end want to 'push' or understeer, the rear bar can be set even more aggressively to the next adjustment hole. What this does (at least in theory) is to give a car the same overall feel at both ends when turning into corners.

Anti-sway bars work by resisting the independent action of the suspension. Put on a bar that is too thick for the intended usage and you may find that the rear suspension will actually lose grip on bumpier roads because the independent action of the left and right sides of the car are negated by the anti-sway bar. Something similar can happen with spring rates that are too stiff for given road - tire/wheel can bounce over bumps and lose contact momentarily with the ground.

Anti-sway bars are just one tool to achieving the right suspension for the type of driving you do (mountain roads, high performance track days on the road course, etc.). There are also spring rates to consider, as well as proper dampening of suspension movement with those different spring rates though the use of aftermarket struts.

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