newbie trying to choose a 13B

[Raksj04]

I was told you can make good power with the N/A rotors in a 4 port engine with a turbo. I think the s4 NA rotors are 9.4 and the S5 is 9.7. and the S4 turbo is 8.7:1 and the S5 is 9.0:1. those where off the top of my head. The RX8 rotors are 10.0:1 but they need to be machined to work in a older engine. I know the apex seals are different and I believe the corner seals will cause you issues. It is just easier to run the 9.7:1 S5 N/A rotors.

here is the ratios and weights, I was off a bit.

Rotors: The S5 rotors have a higher compression ratio and lower weight than the s4 rotors.

S4 13b 6PI: 9.4:1 compression ratio ~10lbs
S5 13b 6PI: 9.7:1 compression ratio ~9.5lbs

S4 13b Turbo: 8.5:1 compression ratio ~10lbs
S5 13b Turbo: 9.0:1 compression ratio ~9.5lbs