2006 Chinese GP Technical Review

Shanghai is one of the new Herman Tilke-designed circuits, and aside from the architectural expanse of the grandstands, the track itself is quite challenging for the cars.

The main challenge comes with Turn 1, where the cars brake and turn flat out for six seconds in an ever tightening corner. This places a huge load on the outer front tyre, and even the power steering gets worked the hardest of all year in this turn.

Further around the circuit, another punishing left hand turn deals out even more abuse to the front tyre. As the circuit has two long straights, downforce is a tricky balance, but as both straights have long turns preceding them, running more downforce will allow a greater speed on to the straight, which partly makes up for the lack of outright speed that is caused by the bigger wings.

This year, with the lower powered V8 engines, the teams needed to run less drag than last year, so they reintroduced all the aerodynamic add-ons that were lost for Monza to improve rear-end efficiency.

Qualifying was wet, and the teams had to gamble on their set-up to balance a good qualifying run against race performance, which was expected to start wet but rapidly dry.

Most teams added more downforce and ran a slightly softer mechanical set-up, but all largely preferred a slightly dry specification with a heavier fuel load for flexibility in pit strategy. The more fuel the car can carry in a wet race, the more chance the team have in pitting for fuel only when a change to dry tyres is possible, thus saving a pitstop.

The wet qualifying conditions suited the Michelin tyres, and even the usual Bridgestone first lap performance couldn't make up for the French tyre advantage. As the race started wet again, the Michelins had the advantage, but as the track dried and the Michelin tyres started to wear, the Bridgestone tyres gained pace.

The cross-over point between wet and dry tyres came near the pit window for one-stopping cars. However, certain areas of the track were still wet, especially in the first sector, and the first set of corners for any driver on dry tyres was perilous, especially for those who pitted early.

Many two-stopping drivers kept their worn intermediates on at the first stop. Renault's Fernando Alonso, however, chose to replace his front intermediates, which caused him problems while the deeper treaded front tyres - compared to the worn out rear tyres - over-heated on the drier track.

Renault did not reveal why Alonso's front tyres were so much more worn than teammate Giancarlo Fisichella's, but several Michelin-shod teams displayed considerable variances in wear between two identical cars.

Ferrari

Ferrari appeared with updated aerodynamics, the most obvious of which was the new shoulder wings. These are much smaller and discreet than those seen on the Italian rivals' cars.

The horizontal section that mounts the fin is similar in size and position to devices used on last year's car: this year, the small fin has a trailing edge that is shaped to match the curve of the sidepod.

These shoulder wings have two functions. Firstly, the horizontal element splits the flow ahead of the sidepods flip-up; and secondly, the fin collects the air passing higher up around the sidepod and speeds it up towards the rear wing. In Ferrari's case, the fin routes its flow around and under the chimney/winglet combination.

Toyota

Having tested the revised sidepods as featured in the Italian GP Technical Review, Toyota raced the new vertical fences in China. They have now been slightly revised to support the small winglet with a small stay on its outer edge.

Williams

For China, Williams had a new Renault-like bi-plane front wing and revised mid wings © Scarborough (Click image to enlarge)

Williams released a new front wing assembly and mid wing for the final three races.

The front wing sports a Renault-like curved bi-plane element. The new upper element is similar at its outer edge to the old cascades, but then the aerofoil sweeps up and then curves down to meet the nose-cone. There is a split near the nose-cone to allow for the wing's removal and a small amount of flexibility.

Williams have chased aerodynamic efficiency all year, and having been able to create enough downforce, they have found it came with too much drag. This extension to the cascades, run on the front wing from mid season, also aims to produce downforce without a drag penalty.

This moves the emphasis off extreme front wing angles to the upper element to create front end downforce. Meanwhile, the mid wing is also all-new, with simple straight winglets sprouting at an angle from the engine cover.

Honda

While the large part of the Honda aerodynamic set remained the same, their diffuser gained an even larger gurney flap.

As with most teams, Honda sported a gurney flap (yellow) on the diffuser, but theirs was even larger © Scarborough (Click to enlarge)

Since 2005, the rules have reduced the height of the outer channels, so the only way to improve the flow through the diffuser is to either ram more in, or find a method of pulling it out quicker.

Honda have found this aggressively large device works for them. They also use a pair of ramps in the middle of the diffuser, whereas most teams only use one.

The weekend started with the team having to work on Rubens Barrichello's engine from Monza. As the work was required on the scavenge oil pumps and not a major engine part, this is allowed under the two-race engine rule.

The scavenge oil pumps are not the main oil pressure pump, but devices used to draw oil from the bottom of the sump. Keeping the sump clear of oil improves power through decreased drag, and it also ensures the oil is cycled around the system efficiently, saving the weight of having to carry extra oil.

BMW's wheel © XPB/LAT (Click to enlarge)

BMW Sauber

BMW have been actively putting aerodynamic parts on their car, but China largely saw more familiar parts along with some minor new parts.

The team again ran the front wheel fairing seen in Monza. The simple extension to the rims are not structural and hence do not fall foul of the rules.

The aim of these devices is to improve brake cooling by pushing the hot air ejected from the front brakes into the airstream. Usually, the wheel is narrower than the bulbous tyre; this fairing pushed the edge of the rim in line with the tyre.

Toro Rosso

Toro Rosso's vertical slit © XPB/LAT (Click image to enlarge)

The team brought another minor aerodynamic update to China: there is now a vertical slit in the rear wing endplate.

This was never a feature of the Jaguar/Red Bull Racing cars, from which the Toro Rosso machine is derived. However, curiously it was often sported by Minardi - the previous incarnation of STR and where the majority of current the technical staff are from.

The slit is used to negate the effect of the larger rear wing endplates, which were introduced in 2004.