Quote Originally Posted by Bridged
And fact is you don't want to go over 15.0 comp on a rotary that's N/A to turbo. So S4 is the only way to go for N/A and turbocharge it. S5 comp plus the ratio of the turbo would end the motor into the 17's on 9PSI. So on an S5 you can only run around 5PSI, which isn't worth the money.
I agree with all of the other options except for the boost level here. 5 psi on higher compression motor can put out the same horsepower as 8psi on lower compression. The difference is that with higher compression you can come off the line easier, and it's a more linear power. That is more manageable on the road course. Of course, the downside is it's more important to have a good tune. Less room for error.