IIRC the mk1 was the same with and without the box. The current one is slightly better with the draft box and little bit more than that for the fin. Not earth shattering reductions in drag but worth it if the rules you ride under allow it.
As above, hunt out the white paper for the details.
Developing aero, fit and other fun stuff at Red is Faster
As above, hunt out the white paper for the details.
Developing aero, fit and other fun stuff at Red is Faster