Last weekend’s Malaysian Grand Prix gave McLaren a glimmer of hope that they are at least beginning to understand the issues with their new car.
But what’s gone wrong? And is there a quick fix?
McLaren made a risky move by making radical changes to their car for this season, introducing pullrod front suspension, a higher front chassis and more aggressive rear-end bodywork.
At the launch, team boss Martin Whitmarsh said: "In changing things you inevitably step back, but this car is already quicker than the car we finished last year with...”
Sure enough, the new MP4-28 hit the ground running in pre-season testing when it set a time more than a second faster than its rivals - but it has since been revealed that the impressive performance was due to a suspension part being fitted incorrectly.
The part in question caused the car to have a significantly lower front ride height and a greater rake (the angle of the car from front to back) than normal for that extra-special lap, and the car would have been illegal in official running.
Since discovering that early test mistake, it has been clear to McLaren that they have actually taken a significant step back.
The core problem appears to be aerodynamic sensitivity.
The front end seems to be their biggest problem because they put a major focus on that area with their flow visualisation techniques during practice in Malaysia.
There are many different devices at work there – the front wing, front wing end fences, under nose splitter, upper chassis, side turning vanes and brake ducts – and the interaction between all these works up to a very complicated airflow regime.
If one thing is not working, it can have significant knock-on effects on the rest.
That is the problem that McLaren is facing – they know they have an issue, they know it’s mainly at the front end, but it seems that as yet they don’t know what part of the front end it is.
It also appears that it is not a simple set-up issue – because with all the testing on track and back in the factory they would have worked that out by now. It is the dynamic behaviour of the car out on track that is causing the confusion.
Teams can vary static set-up ride height but as the car travels around the circuit, the bumps and the dynamic loading compress the suspension causing much more significant changes in ride height.
The lower the car runs to the ground, the more it benefits from ground effect that enables the lowest aerodynamic surfaces and devices to create more downforce with relatively little increase in drag.
However, if worked too hard the airflow can separate from the surfaces and lose downforce, or vortices can develop that create turbulent airflow and affect the performance of other parts.
That’s all very confusing if you don’t know where or why this is all happening.
McLaren’s initial solution has been to simplify the aerodynamics at the front end and to run the car with stiff suspension to reduce dynamic ride height travel – but that reduces front-end mechanical grip, particularly on bumpy or slippery circuits, because it reduces the amount the tyre contact patch is in contact with the ground.
However, either the track in Malaysia suited them much better or something they did there seemed to work.
In Australia, the fastest time of the weekend was a one minute 25.908 seconds from Sebastian Vettel, set in second practice. McLaren’s fastest, also in that session, was a 1:28.294 from Button – a deficit of 2.386 seconds, or 2.7 percent. That’s a massive margin for a team like McLaren.
In Malaysia, Mercedes’ Nico Rosberg set the fastest time of the weekend in Q2 with a 1:36.190. McLaren’s best in that session was a 1:37.117 from Button – just 0.927 or 0.96 percent off the pace – and their best lap of the weekend, in P3, was 1:36.822 – just 0.632 or 0.66 percent off the overall best time of the weekend.
Then, in the race, Sergio Perez actually set the fastest lap with a time of 1:39.199 on lap 56 – although many of the lead contenders had slowed down by then to conserve tyres towards the end of the race, when cars are lower on fuel and therefore can run faster.
McLaren’s lack of understanding from pre-season testing meant some of the development parts planned for Australia didn’t go onto the car – putting them another step behind their rivals before the season had even begun.
But despite the promising signs in Malaysia, there are still concerns.
Sporting director Sam Michael admitted the team is trying to fix “two or three different areas” on the car so although McLaren’s quick fix may appear to have got them back into the mix, it seems the long-term solution could actually still be some way away.
That said, if they can limit damage now and eventually fix the problems then by the end of the season, their gamble on revolutionary rather than evolutionary development for 2013 could still pay off...