Vincy,
The preload on the sway bars (as I understand it) is used to help offset the "crown" on most of the roads that we normally drive on the street, i.e. crowned roads for water drainage. Race tracks don't normally have a "crown" to them, so you don't need this preload on the track.
If you remove the preload with adjustable sway bar end links, you can make the car more neutral, i.e. so that it will turn in well and feel about the same in both directions. It will not weaken sway resistance, it will, all else being the same, help equalize it.
Hey Dan,
The asymmetry you speak of from the factor is done via a left to right imbalance in the front suspension's caster settings - usually a little more positive caster in the right side.
Swaybar preload is something to be completely avoided in anything but (maybe) a circle track car. It leads to an asymmetry in handling balance (understeer/oversteer) when turning left vs. right. One would hope that the car would have no/minimal swaybar preload when stock, but the only way to be sure would be to get adjustable endlinks and set it to zero, optimally with the car in the condition (fuel and passenger load) it'll be in when you care about it (aka race trim, if you race).
I don't know how much larger I'd go with the front bar on a stock car, especially if you're sticking with the stock tire sizes and compound. They push pretty bad stock, even with a good alignment. In general, stiffening the front sway bar will tend to make a car understeer more, so you would at least want to go with a matched front/rear pair. Also in general, I wouldn't recommned someone perform any handling-altering modifications to their car (with the exception of an alignment, which will extend tire life) until they have enough experience under their belt to have a sense for what they'd like to change about the way their car handles. The Viper, even the regular one, is already much closer to a full-on racecar than most cars will ever be even in a highly modified state.
I think a lot of the Vette guys look to swaybars because of how much of a (relative) pain it is to change spring rates on the Vette because of the transverse leaf springs. The Viper uses conventional coilovers at all 4 corners, making spring rate changes easy, and swaybar changes less often used for tuning.
I hand-built a custom front swaybar for my car for not too much $ using components sourced mostly from Speedway Engineering. I run Hoosier A6 tires 315 or 335-18 up front, and 345-19 rear though; the large addition of front grip is offset by the stiffer front bar, which, simply put "takes some of it away".
