Do I add the front sway bar at the same time I'm changing to R-compound tires or do I first learn the new characteristics of the car w/out the bar. All this year I've been running on the stock 050's at auto-x's and HPDE'S. I'm a veteran racer but new to the S2000. I've read that with the larger front tire (225 fr/255 r) and running race tires the S2k "likes" to have a stiffer front bar. So this leads me to believe I should do these upgrades at the same time.

Also, for my knowledge why does the S2k need the stiffer front bar as this only adds understeer. Is this to reduce the oversteer the car will experience with R tires?

 

http://forums.s2ki.com/forums/index.php?showtopic=172595

 

In addition to the autocross FAQ above.

I've done 2 years of autocross, the first year stock, 2nd year with RA1's with stock tire stagger (205/245 on a pre '04 car). With street tires, you don't really require any changes (Unless you are on a really grippy surface). With "non-sticky" R's, you can lift the inside rear wheel on hard braking and turning. The stiffer front bar is to prevent the rear wheel lift, but you balance the increased understeer with a 225 front. I'm going with the autocross "formula" for season 3. If you don't care about being BStock or ASstock now you don't have to go that route.

From a roadcourse perspective 205/245 (or 215/245? for you) is a very good balanced setup on street tires or R's with the stock suspension. The R's extra grip does give you more roll in the corners, but its not too excessive. I'd just give it a try with the stock setup, and since you're more experienced, you can judge for yourself what tire/suspension tweaks a good. There is a lot of track dogs old threads to get the more extreme setups.