I've been searching the forums and haven't had much luck on finding anyone that has upgraded their stock sway bushings to polyurethane bushings that would fit the Mazdaspeed front and rear sways.

Any recommendations? I like the greasable sway bar bushings that Energy Suspension has but they don't have one specifically for the RX-8.

I saw the DPE posts about the bushings they offer, but it seems that they are out of business!

 

Energy Suspension should have one to fit your needs, just need to do a little measuring. http://www.energysuspension.com/pages/swaybbct.html

 

I know the diameter for the Mazdaspeed sways (27.2mm front and 17.3 mm rear). It seems that I should get a 27mm bushing for the front and 16 mm bushing for the rear, but what about the front bracket (they have two sizes)? 17.5 bushing for the rear doesn't make sense because it would be too big right?

 

The brackets for the rear are too big to fit at all. On a stock setup, the fronts will overlap the ABS line bracket, so the ABS bracket will have to be mounted over the sway bracket. The first type is the closest match, but still makes the bar sit slightly higher than stock. The second type would be higher yet.