I have a new rzr4 and I have to say that I am very impressed, except for the power. I have had everything from dirt bikes to twin turbo sand cars. For the most part I don't go to the dunes anymore so I don't need anything crazy. I would love some dependable power without a bunch of head aches and a bunch of noise. I would like to keep the sound stock if possible. I have been trying to choose between a low boost turbo, a supercharger or a big bore kit. The three I have been leaning towards is the arrow charger, mpi super charger and Holz stage 3. I am not a fan of turbo lag and I spend the majority of my time on mountain trails and the desert.