Roller cam and turbo charging

224 sounds like a pretty decent cam. What a lot of folks don't understand is that high duration numbers with a turbo is sometimes the opposite of what you want. You don't want to hold both valves open nearly as much as a NA motor. You don't really need to use the scavenging effect of the exhaust to help draw in the mix from the intake (like the basic principle of a 2 stroke) The turbo does all the work and forces the mixture into the chamber.