Can a major engineering upgrade of the MP4-28 rescue McLaren's season?

Jenson Button's entire 2013 season probably hinges on what happens at the McLaren Technology Centre in the three weeks between the Malaysian and Chinese Grands Prix.

Just as the McLaren's airflow can be made to behave normally above a certain ride height window, so it seems there is a ride height below which it will also work. But that ride height is too low to use in race conditions - and therefore cannot be used in qualifying either, because of the parc ferme regulations. It is believed the car was running with this super-low ride height when it set the fastest time of the first day at Jerez testing. At Malaysia the car was improved compared to Australia by the team running the car relatively high, above the ride height that triggers the most severe of the buffeting phenomenon. Although such a ride height sacrifices downforce to rivals that can run lower without problem, reducing the bouncing brought more gain than the loss from reducing peak downforce. "We were at least 1.5s off the pace in Australia," said Button in Malaysia, "but if qualifying had remained dry here I think we would be maybe 1s off, maybe even slightly less. It's helped by the fact that Sepang is a smoother track than Albert Park, but it's also from improvement in the car from the way we're running it." Obviously, the aim is to be able to ruin a conventionally low ride height but without triggering the airflow detachment. The team believes it learned a lot about why the detachment problem is arising from on-the-hoof modifications made in Sepang, including crudely 'cutting and shutting' the contours of the diffuser, in order to energise the flow better around the crucial areas where it is detaching. Whilst it's surprising that the powerful simulation tools of McLaren did not pick up on the aerodynamic problem before the car actually ran, the team is running absolutely flat-out in the break before China to have heavily upgraded cars in Shanghai for Button and Sergio Perez. Don't bet against a total transformation of form.