I have a S5 na rx7 and were looking for rotars. Will the rx8 rotars fit and work in a S5 na motor with S5 turbo housings? Would there be any preformance added to the motor Or do I need to stick with the S5 rotars.

 

It's spelled 'rotor'. The compression ratio is probably different, and if so then you can't just swap them in without making fuel adjustments and probably timing adjustments, too.

 

Plus the RX-8 apex seal grooves would need to be machined deeper to accept 2nd gen apex seals.

 

s5 rotors are 9.7: 1 compression ratio and the rx-8 rotors are 10:1 comp ratio, you could machine them to fill depth 2mm so you can use the earlyer seals or you could just use the stock rx-8 seals which actually seal really well. the side seals on the rx-8 rotors are also different they are a little fater and tapered, so if yo are going to use the RX-8 rotors you might as well just use the stock apex seals and side seals