The start of the European season in Spain marked the ramping up of Formula 1's development race that will now be a feature of the remainder of the campaign.
For some teams, the updates that were brought on to their cars were a means to close the gap on the faster opposition, while for others it was to dial out problems that were discovered in the opening flyaways or simply refinind areas to make them even better.
Red Bull's Brakes
One of the main talking points at both the Spanish and Monaco Grands Prix was Red Bull Racing's brake system especially after the problems the team faced in this area.
Sebastian Vettel suffered a freak disc failure at Barcelona, which led to him running off the track at one point in the closing stages and limp home a fortunate third place with no left-front brakes at all.
That fault was caused by the disc splitting in half radially - something the team had never experienced before and something it worked hard on to make sure would not happen again.
Looking at the photographs of the brake system and how it evolved and developed from the Spanish Grand Prix and throughout the Monaco weekend shows how critical this area of design can be.
What happens on an F1 car is the brake disc is mounted on bobbins to a metallic disc bell.
These bobbins semi-float on the disc bell to allow the disc to run true, and also have a bit of space to allow for the difference in material expansion caused with the temperature fluctuation which ranges from 300C up to 800C during a race.
The disc bell is titanium and is the first thing you can see on the left hand side of the disc. It takes the braking torque through from the disc to the wheel drive pegs, and ultimately into the wheel and tyre. The torque is not equally fed into the disc bell as the bobbins try to twist, which means the disc structure from side to side is very important. This area also has to withstand the compression force when the driver stamps on the brakes.
The discs themselves feature radial cooling holes, and getting the balance right between the right size cooling holes and the right amount of material mass to accept the massive heat input during braking is a tough balancing act. If the disc is not stable enough then it will fail and fall over in this area which is probably what happened to Vettel in Spain.
That is why you can see such a change between the disc design Red Bull Racing had in Spain, what is ran on the Thursday in Monaco and what it ran from Saturday. There is obviously a move to running a stiffer assembly for Monaco, which is better able to cope with the forces, but then further tweaks were made over the weekend.
Red Bull's exhausts
There are still a lot of people in a lot of teams scratching their heads trying to understand exactly what they can do to close down the performance advantage that Red Bull Racing enjoys.
One area that is getting an increasing amount of attention is the exhaust layout of the RB6. Although it is not the magic bullet in terms of providing the whole answer as to Red Bull's pace, it is certainly one of the main elements that is working well in its package.
The rear of the RB6 is unique with the use of pull-rod suspension, the size and angle of the gearbox and the low-mounted exhausts which all contribute to a tightly-packaged rear-end. But this isn't only the area that stands out - it is the attention to detail that really gives the team an advantage, plus the fact it has pushed very hard to reduce the losses.
Cars create downforce from making components work harder, but you will always pay a price as far as drag is concerned. For any racing car, a component will produce a certain amount of downforce and a certain amount of drag. It roughly works out that for every 100 kilogrammes of downforce you get for your car, you will create somewhere around28 kilogrammes of drag so roughly an L/D ratio of 3.5.
Some of the body surfaces over the top of the car also create lift (in other words actually try to lift the car up) which is really something that is not good for any racing car. Any lift these surfaces create also generates drag at more or less the same L/D ratio so it is important that you can get rid of anything in this area that creates lift.
Red Bull have done that a whole lot better than the other teams. Also, by putting the exhaust pipes down low, plus the pull rod suspension the team has not only reduced the blockage to the rear wing, but it has also helped produce more airflow through that area which in turn helps the diffuser function much better.
But there are other benefits too. A lot of teams try to utilise the exhaust gases for improved performances throughout a corner. A driver will be off-throttle under braking, part throttle through the middle of the corner, and full throttle on corner exit. With all this change of mass air flow to downforce-producing-devices there will be a characteristic change in the handling and balance of the car. The question is, does it make the car better or worse, or is it just that bit more confusing?
Managing that change of mass airflow over rear wings can be quite difficult, because the hot turbulent air is hard to control. What Red Bull Racing appears to have done is move to an area where there is a minimum characteristic change. Just like the way the rear of the car is structured, it's all about minimising the negatives.
The fact that the car is so well developed may well explain some of the reasons as to why it is so good on Saturdays, while on race days its advantage is not so obvious. It looks like aerodynamically, either through the underfloor or ride-height demands, that it doesn't actually have a critical area.
The car can run a bit lower or a bit higher and it still produces good downforce whereas for some cars just 0.5 millimetres of ride height and the extra downforce it produces can mean everything.
All of that comes through good airflow and aero management plus its suspension. This all boils down to the strong concept that Red Bull Racing has and the fact that it totally believes in it.
On the pull-rod issue, a lot of other teams would have looked at it over the winter and not have bothered with it, whereas Red Bull Racing believed in it, developed it, re-developed and then re-re-developed it. A good car gives the driver the confidence to do amazing things and we have seen that from both Mark Webber and Sebastian Vettel this year.
Ferrari's F-Duct driver control mechanism © LAT
One of the areas that several teams have spent a lot of time working on this year has been F-ducts as they try to seek out some of the advantages that McLaren's system has brought this year.
There are two ways of getting an F-duct to work: either by creating airflow to stall the rear wing and make it faster in a straight-line, or by creating a wing concept that you can introduce flow to so that you reduce its performance, and thereby reduce drag. In both cases you have to lose downforce to lose that drag.
If I was creating an F-duct, I would be looking at reducing the performance of the rear wing, because then, for the driver, he would have a tool that was able to change the characteristics of the car. This is especially useful for McLaren, whose drivers use their knee. It means they can use it not only on the straights. If say, in a medium/fast corner they had some understeer and wanted to make the rear wing work a bit less, they could just close off the duct with their knee - which would alter the level of downforce produced by the rear wing and, hey presto, a better balanced car.
Other teams that are playing catch up have not had the luxury of being able to introduce their systems exactly how they may have wanted because of the chassis homologation rules introduced this year.
Ferrari, for example, have had to locate their slot opening quite high in the cockpit so the driver has to close it off with his hands. That is not ideal if you are using it as a corner balance tool, because you really want your driver to have his hands on the steering wheel at all times.
And because drivers Fernando Alonso and Felipe Massa use different types of steering wheel, where the slot was in relation to their hands on the wheel was also different - with Massa having to move much more.
Ferrari also found that by stalling the rear wing, it becomes quite unstable and more importantly is inconsistent when trying to get the air to reattach itself at the end of a straight just before braking. That could be why the team said after Spain that there was a downforce compromise from using the F-duct system.
It seems teams have put a lot of work into the F-ducts with a very small return in lap time. And while there might be a decent return in terms of straight-line speed, that is probably only useful enough for defending someone, not enough to be able to pass them.
Mercedes updates aplenty
Although a lot of teams introduced their latest development packages at the Spanish Grand Prix, one of the biggest overhauls was undertaken by Mercedes GP.
The team had come into the year admitting it had made a mistake with its weight distribution, and the updates to the W01 were primarily motivated by trying to improve in this area.
This year the front tyre is narrower which means it can take less load. This means there is a limit as to how much use you can make of moving the weight distribution forward because above a certain level the tyres will simply not produce any more grip.
Over the last few years the ideal is to have a front wing assembly where you can increase the downforce without hurting the airflow to the rear of the car. The more front wing you have with no loss of rear downforce, the more the centre of pressure moves forward and the more total downforce you have. But to cope with that, you have to move the weight distribution forward.
If, however, you have a front wing that with more angle starts hurting the rear downforce of the car, then if you can't put the weight forward you get no gain from it. The Mercedes GP front wing could be like that - not helping the rest of the car when it should actually be increasing performance.
In a bid to overcome this problem, Mercedes GP has moved the weight around the best way it can which was by moving the front wheels forward by 5cm.
This has helped the team with getting more use out of downforce at the front of the car, but also by lengthening the wheelbase it has also made the car less nervous. Plus, with the driver being a bit further away from the front wheels, he will be able to feel what the car is doing better and be more precise with it.
Although there are negatives from increasing the wheelbase, which can include making the car feel more lazy, making the driver feel happier is important as well. Although for a team, when you change things you do it for engineering reasons and not necessarily for making drivers happy.
I did the same in the past at Jordan, when I moved the front wheels forward 50mm and it suited Damon Hill but didn't suit Ralf Schumacher. Ralf was happy sitting and coping with a nervous car, while Damon wanted something a bit lazier. That is just the way it was.
Looking at how the Mercedes GP drivers coped with it, it is clear that Michael is very good at knowing what he wants from a car as far as engineering is concerned, and was probably the driving force in instigating these changes. Whereas Nico is a man who has a reputation for just picking up what he has got and getting on with it.
Mercedes unique airbox layout © LAT
The other area of interest on the W01 was the unique airbox that the team introduced at the Spanish Grand Prix.
To understand what the team has done, we have to consider that, with the ban on refuelling, fuel tanks are bigger in 2010 and that means the airbox intake has lengthened dramatically. The size of the airbox intake should in theory be based on the engine getting the maximum flow of air for when the driver is on full throttle.
Then you have to take into account what happens in the airbox which is effectively a big long bit of tube with a plenum area at the end of it over the trumpets. You need to get the air distribution over the trumpets of the engine to be uniform, but inside the airbox there is a lot of pulsing that goes on as each trumpets fires.
To make those pulses not have an affect on engine performance, the length and or volume of the airbox intake is important. With a long inlet tube those pulses and the harmonics within the airbox are restricted and cannot dissipate themselves to the atmosphere. By shortening the inlet, you open those pulses to the atmosphere earlier, so when one trumpet is firing it is not affecting the other trumpets.
Mercedes GP has tried to reduce the losses from within the airbox design. In the past I have seen in excess of 10hp simply by improving airbox flow, but with their shorter airbox intake Mercedes GP should get better torque characteristics at the lower end. I don't think there will be much of a power advantage as such, but definitely there will be a better torque curve.
In aero terms, the design doesn't make a big difference. The inlet is still there, dragging in the same airflow, and you still want the air spillage that happens at high speed to stay attached to the engine cover.