Rx8 anti roll bars..

Paid £50 for a mint set off an imported RX8 locally :wink:

Yellow dot RX8 bars will give you an increase in roll stiffness which gives a better feel on turn in. It does this at the expense of grip for road use. If you have lowered springs and standard dampers and want to change the balance, drift washers on the rear to introduce the spring assister (bumpstop) earlier will reduce understeer in steady state cornering.
I have run with yellow dot f/r in gymkana and tested the washers in successive runs until I found a good balance.
Interestingly the MX5 Eibach / Mazda Speed (MS) bars

Diameter front bar – 26mm, wall 4mm - Ip=34,555

Front
arm adjustable at 172 or 192 mm on one side only (stnd ~182) effective Ip ~ 35,522, or 33,614

Diameter rear bar - 16mm, solid bar - Ip=6,430

Are close to an orange rear and yellow front bars. This moves the attitude towards oversteer.

I will be removing the yellow dots to go back to standard green dot front / blue rear when I change the springs and dampers to a new Bilstein spec.
If you are running aftermarket springs and dampers like Meister R and having too much roll better to discuss the spring rates and damping settings than whack on big bars for a road car.