It looks like you run RB's... well IMHO you don't need to modify, port, or polish these engines... they have an engine for every possible power band you want... if you want all out power get the C6BB that will be more than you can probably control in any buggy. Personally in my buggy I prefer the power of the S5 because I am able to control the power much easier and actually run better lap times with it than I do with my WS7II or C5BB