Sauber C31 – diffuser launch spec details

 

    C31 diffuser may  lack any eye-catching innovations but is nevertheless full of interesting details . The roof tab is slotted to allow portions of air bleed through hence reducing drag, a trend carried over last season and pioneered by Toro Rosso STR6 . There are three vertical fences , two of the same height and an outer shorter , at both diffuser sides symmetrically placed to allow not any  interaction between the air flows travelling through the  channels formed by the fences . The centre part ( magnified ,in the inset above ) looks very interesting and totally different than that of C30 -2011 car . It clearly exploits aerodynamically  the motor access hole to gain extra downforce . The flow travelling around sidepods bottoms reaches the slim rear end and penetrates through the starter hole to rich the diffuser zone to increase diffuser ability to pull air from under the floor. The contribution is enhanced by the warm air escaping from holes in the area of the gearbox and aided by a little flap . That flap apart from its aerodynamic role reduces the overall size of the engine starter entrance to comply with the  article 3.12.7  of the FIA technical regulations . Not far in the past that hole raised significant protests against Mc Laren which forced FIA to further clarifications about the size of the hole .