Rarely are two races so different as Valencia and Spa, both in how the teams fared and how the tracks are laid out.
The back-to back-races started with Valencia, the slow, twisty circuit demanding high downforce and a soft grippy set-up, while Spa, with fast turns, demands little downforce and a stiff but progressive set-up to keep the aerodynamics stable.
As well as the different circuit arrangements, the weather saw a return to high temperatures in Valencia, and then the cooler temperatures in Belgium were offset by the load the track puts into the tyres maintaining their heat. Regardless, both races were as much a matter of getting the best out of the tyres, as it was finding a general set-up for the track. Broadly speaking, overloading of the tyres in Valencia lead to rear tyre graining, while maintaining front tyre temperature was the opposite problem in Spa.
Valencia's race followed a four-week break after Hungary, with the teams forced to close their doors for two weeks. Notwithstanding the enforced shut-down and ongoing testing ban, most teams developed major new parts to debut in Spain.
Such was the pressure to get the new parts that most teams didn't have enough spares or even enough parts for two cars. Then more parts along with further developments arrived for Spa. So we continue to see the team's fortunes vary with weather, track layout and where they sit on their development path.
A classic example of this is Force India, who found all three factors played into their hands to nearly leapfrog the entire field in Belgium. No fluke, merely the grid is so close on performance that a car with its latest raft of developments on a well suited track was able to work its tyres perfectly and outpace the opposition.
Equally Spa was the first race where the cars have run significantly less than maximum downforce, its higher speed turns allowing smaller wings to create the downforce needs. Teams that have perhaps struggled to create enough downforce or have purposely opted for a more efficient but lower downforce set-up excelled on this track.
No other track has this set-up requirements, not even the upcoming Monza circuit, which also demands low downforce but lacks any demanding turns, meaning that the status quo in Belgium is unlikely to continue.
From its lacklustre beginnings, McLaren's development pace has been astounding this year. Valencia saw a major upgrade to the car, both on its aerodynamics but more crucially on its layout, with a wheelbase reduction. This was not to make the car suit the twisty demands of the Valencia street circuit, but to alter the weight distribution. The front wheels were brought back some 7.5cm towards the rear.
Lewis Hamilton at the European GP © LAT
This effectively placed weight over the front wheels, in order to make best use of the Bridgestone tyres. After the last major upgrade in Germany, the car ran a 48% forwards weight distribution. All else remaining the same, the short wheelbase would move weight 1% further forwards, placing another 6kg over the front tyres.
It continues to be the case that the relatively wide Bridgestone front tyres are able to accept huge loads in comparison to conventional race car practice, where 46% front-54% rear is considered excessive. McLaren's latest 49% forwards bias is extreme, but potentially typical for a 2009 F1 car.
A corresponding change with this weight shift is more front end downforce to balance the car. McLaren tried several front wing iterations over the two weekends, including a complex endplate arrangement in practice for Valencia. The Brawn-like set-up removes the upper endplate and replaces it with a vane placed further outboard. This vane acts as a mini bargeboard, but is largely there only to meet the regulations for minimum surface area. Thus the vane is only half height compared to the Brawn solution. This endplate was not raced and the more conservative vented endplate was retained.
On the front wing itself, McLaren tried several variations, one set-up placed the camera pods low and forwards on the nose cone, while a Spa variation saw the main plane notched out to ease the pressure difference between the neutral centre section and the wing itself.
Toyota joined several other teams when they tried an extended front wheel fairing. It was a simpler version than that of the McLaren or Ferrari solutions.
Kimi Raikkonen at Spa © LAT
Compared to the opposition. the F60's developments were more muted. The car sported a revised diffuser and the rear brake ducts were more intricate and wing-like than the previous versions. While the exhaust outlets were closed up to a simple circular exit in Spa, possibly a test for the Monza low drag set-up.
While the rear wing was all new for the low drag demands of Spa, its upturned central profile reduced drag and reduces load on the narrow rear flap.
The flap itself is even narrower at its tips in order to reduce the vortices created at the wing tip. This wing will probably be used for Monza with a slightly different angle of attack to meet the even low drag demands of the track.
Although seen running very different bodywork parts in a straight-line testing before Valencia, the test was in preparation for Monza, with brake ducts, low drag wings, blocked off diffuser and revised vanes under the nose of the car.
Only the new inner brake ducts were ran at races. Much like Brawn and McLaren's extended versions, the duct reaches forwards to the front perimeter of the tyre, unlike the outer wheel fairing, and it has more space to extend to the side of the tyre, without forcing a narrower front track.
Possibly related to the change was a large fence added to the existing front wing support. The fence primarily acts to keep the wing elements connected to each other, but the new taller fence is an aerodynamic aid to prevent airflow passing from the high pressure region to the low pressure region above the neutral middle wing section.
Pressing ahead with development, BMW arrived as announced with updates to the car, before the major upgrade in Singapore. The Valencia upgrade was a second step in the KERS-less sidepods introduced in Spain. Now the sidepods are even more undercut, making use of the space the lack of KERS hardware creates.
Along with this, the pod wing was revised and now runs the full height from floor to sidepod top. Matching the undercut is the coke bottle shape which is also much more undercut. Finally the shark fin was returned the spine of the air box cover.
Red Bull's most obvious development for Spa was the new front wing cascade. The previous curved two-element flap over the main wing has been broken into two discrete sections. Firstly the outer span is a deep box-like winglet, while the inner section retains the slender two element shape of the previous cascade.
Much like Honda's 2008 low drag rear wing, in Spa Williams tried a low rear wing the flap not reaching the maximum permitted height, while the main plane had its edges turned down at tips to reduce drag.
Brawn has struggled with tyre temperatures, but the heat in Valencia, and then the more abrasive surface and highly loaded corners in Spa aided the team. Button, however, struggled to get heat into his front tyres, as his driving style does not put load into the front tyres as much as other drivers.
Jenson Button, Brawn, Belgian GP © LAT
Development appeared limited for Spain, with just the new pod wings making an appearance. Then in practice in Belgium new front wing endplates, rear wing and engine cover made an appearance, the latter not being retained for the race.
Bearing in mind the Honda team's history of oversized pod wings, their absence on the Brawn has been surprising. Their function of controlling the impact of the front tyres' wake on downstream bodywork seems a universal requirement for modern F1 cars; finally Brawn added these devices for Valencia. A simple full height vane was added to the shoulder of the sidepods, trimmed around the broadest part of the sidepod and twisted to align with the undercut below this.
At the front, the new endplate followed the squarer profiled set-up first introduced at Silverstone, but with the addition of an extra vane on the footplate. The plough-like shape of this vane appears to send airflow under the footplate and around the outside of the front wheel. Probably in conjunction with the pod wings to control airflow further along the car, while at the back their new low drag rear wing utilizes a large flap and shorter main plane is mated to sculpted endplates.
These endplates appear to provide a huge range of adjustment to the angle attack of the wing. Presumably, so that the wing can be used in a shallower set up for Monza or lowered as with Williams' low drag wing. Aiding drag reduction is a set of louvers lower down the endplate to relieve pressure build up where the beam wing meets the endplate. Lastly, and possibly appearing at Monza, was a new top body, with a shark fin tail and revised exhaust and cooling outlets.
Giancarlo Fisichella, Belgium © LAT
Still one of the lesser funded teams, but with a clear development plan, Force India introduced its second major upgrade to follow the Silverstone package that made its debut five races ago. Formed largely of a revised front wing and all new sidepods, the upgrades' benefit was not that noticeable in Valencia, but made a far bigger impact in Spa. The front wing apes Brawn's cascade winglet, while the foot plate mounted vane gained two elements linking it to the cascade element.
Yet it's the sidepods that were the biggest change: with no plans to run the McLaren Mercedes KERS system, the space recovered for the PCU and battery could be recovered, the sidepods slimmed considerably. This is seen in the new inlet (taller and narrower) and bigger undercut.
The humpbacked and bulged shape of the previous coke bottle shape was streamlined and the cooling bulge raised to free more airflow over the top of the diffuser. Also aiding this downstream flow was the loss of the moulded-in pod wing and its replacement with a simpler pod wing and bargeboard arrangement. These changes were quoted as being worth 0.7s which clearly showed in Belgium.