McLaren MP4-24 - cut-out rear floor 23 March 2009
McLaren have introduced something completely new for 2009 - a floor with a cut-out section in front of the rear tyres. Its aim appears to be to increase the effectiveness of the rear diffuser by effectively turning the whole rear bodywork area into one large diffuser, with the 'throat' of the venturi starting just ahead of the back wheels. The delta-shaped leading edge of the cut-out creates low pressure, encouraging the diffuser to pull in more air at a faster rate. This solution is possible because with no more flick-ups (banned for 2009) on the upper bodywork, it's no longer essential to retain the uniformity of the lower floor area. It remains to be seen whether this is a pro-active measure from McLaren, or a reaction to a general lack of downforce.