C16 lays more in the RPM range of the Stage6 racing. The sport performs verry wel with exhausts like Yasuni R, Polini 4race, Gianelli Shot and so on.
Metrakit SP exhaust will do quite well too, for sure.
edit: I've seen dyno prints of an Aerox with Stage6 Sport + 19mm carb + yasuni R It scored a bit more than 10HP