so i just ordered an evader and pretty much have heard that the stock dtx engine is really hard to tune
so i decided to get one of these...
1 OS 18 CV-RX or
2 OS 15 CV-X
please suggest what you use and how it performs and suggestions on other engines

also if i get one of those what pipe do in need to get
i really dont understand what they mean by side exhaust etc etc

these are going into a nitro evader st
please suggest

THANKS!