I have a extra rx8 front stationary gear and FD rear stationary gear laying around. Want to use them in my 4port 13b made from 12a side irons. I know it's a over kill with 3window bearings and hardened gears for a NA build. Already cut down the 13b gear to 12a height. I'm trying to avoid having my whole s5 NA rotating assembly rebalanced. Everything I've read from racing beat says you have to use the rx8 front counter weight with rx8 thrust spacer and thrust bearings. To use the rx8/FD front stationary gear. I don't see why I couldn't use the earlier thrust bearings and thrust spacer. Anyone have any experience with the FD or rx8 front stationary gears with the earlier smaller front thrust assembly?

 

I may be wrong, but I was under the impression the 3rd gen and Rx-8 front stationary gears were interchangeable. If so, you could use a 3rd gen front counterweight as IIRC S5 and 3rd gen rotors weigh the same. Maybe someone else knows for sure or a call to Mazdatrix or RB could clear ir up.

 

I think u maybe right. S5 and s6 share the same rear counter weight. I was always under the impression that the front counter weight was balanced with each set of rotors. On RB web site it says u need to have everything balance if u replace the front counter weight. Something I'm trying to avoid.