Technical analysis – Austria

F1i technical expert Nicolas Carpentiers provides you with images and explanations of the technical concepts and novelties spotted at last weekend’s Austrian Grand Prix. 



McLaren unleashed a new spec of rear wing on its MP4-31 at the Austrian Grand Prix, which featured unique eye-catching endplates.

Rear wing endplates are usually fairly similar from one Formula One car to another and comprise the following series of aero elements. The strakes guide the airflow upwards; otherwise the air tends to dip (see 1 above). The lower endplates are usually serrated, with the curved winglets pushing the air to the outside, which in turn contributes towards expanding the airflow out of the diffuser (see 2). The horizontal louvres in the upper areas aim at reducing drag by diminishing the pressure differential on both sides of the endplates (see 3). Finally, the vertical slits located at the edge of the endplate and near the rear wheels are here to curb the impact of the turbulent tyre wake (see 4).

The revised McLaren endplates seen in Spielberg certainly gave food for thought. While the louvres are still there, the strakes are no longer curved upwards; they have a flatter outline, are made out of metal, and seem to serve a more functional role, i.e. to increase rigidity, instead of being aero elements (see yellow arrows). The vertical slits were kept but these start from higher up (see red arrows), and it would appear the vanes were simply lengthened.

More intriguing is the fact that these elongated curved winglets now guide the airflow inwards (instead of outwards). One possible explanation would be that the vanes channel high-pressure air on the inside of the endplate, namely the lower-pressure area under the rear wing’s main plane. While this would decrease downforce it would also, most importantly, reduce drag by weakening the vortex generated at the joint area of the endplate and wing tip. This solution is quite popular with teams like McLaren that lack straightline speed. The curvature of the winglets could help level the pressure, which would in turn minimise the loss of downforce while still reducing drag.

These are naturally just hypothesises at the moment and only McLaren chief engineer Peter Prodromou and his team know exactly the rationale behind the MP4-31’s new rear wing. Given how radical the element appears to, one can surmise its function is rather complex. It won’t come as a surprise then to see the Woking-based outfit carry out further tests of the upgrade before racing it.