The D1SC provides 200 more cfm (1400) than the P1SC and the boost curve is more aggressive due to its impeller design. If you have some modifications or are planning some such as heads/cam and a good exhaust the D1SC kit with the twin intercoolers would be a good system that can grow with you.

If you plan on leaving the engine stock or nearly so then the P1SC is a great all around unit and the boost comes on more linear. The head units are also upgradable at a future date if your plans change down the road.

Both headunits are available in a kit with the twin intercoolers and a less expensive kit is available with a single 2 core intercooler (8psi) and the P600B or P1SC to get you into supercharging quickly.