I have had a lot of customers purchase Mazda RX8 front brakes but they do not know if they have sport or non sport suspension. Here are ways to tell if you have sport or non sport suspension brakes. This is only for the 04-08 Rx 8 or the first body style.
The difference between the sport and non sport brakes is that the front rotors are a different size. One sure way to determine which rotor you need is to simply measure it. Sport should be about 12.72 inches and the non sport would be 11.93 inches. The next and probably easiest way is if you have manual 6 speed transmission, then you would have the sport suspension. Automatic transmission users will probably have to check if their sway bar has a yellow or red mark. You can check for the mark on the sway bar which is just behind the passenger side tire, you can see it by turning the wheel all the way to the right. If it is yellow then it is a sport.