2007 Japanese & Chinese Tech Review

This year's season ends with a final trio of flyaway races. The first two of these were back-to-back races in Japan and China. These pair of Asian races had striking similarities in terms of design, layout and weather.

Fuji in Japan hosted to round 15 of the championship. Visited for the time since the 1970s, Fuji has been heavily revised by Herman Tilke.

As the track was unknown to the teams, the circuit layout had to be simulated to assess the ideal set-up before arriving at the track. The rain that blighted the weekend made it hard to ascertain who made the better job of prejudging the circuit.

China, meanwhile, has has been on the calendar for four years, however this totally modern track was also designed by Tilke.

As the races are the same region it was not surprising that their weather was similar. In Japan we saw the first race of the year start in the wet and then never really dried, while in China light rain begin just after the start then dried from the middle of the race.

With all official F1 testing now complete for the year, no testing was possible between the races, although a major test in Jerez preceded Japan.

As the last races are all largely tracks with medium demands on brake, drag and downforce, many teams opted not to run major new developments, because either their packages are already well-suited to these tracks, or the team have already redirected development towards 2008 (BMW, Renault).

While major technical developments were thin on the ground, most teams were still able to put some small final developments onto their cars.

Typically, the Japanese teams make an effort for the home race, as the engine freeze meant that one-off engines cannot be developed, and therefore the chassis has come in for extra attention.

In Toyota's case this was a special project, while Honda's efforts are aimed at a new bargeboard philosophy that was solely used in testing.

Fuji layout

A summary of the track provides an equal mix of three requirements. First is the unusually long start/finish straight (1.5Km) which ends with a tight pair of corners.

Then, the track opens up to a sequence of fast turns through Coca Cola and 100R. A short back straight leads to the last sector, which moves into a continuous run of seven tight turns.

In the end the teams ran a fair amount of downforce, not just for the wet sessions but as part of their baseline set-up.

The long straight demands low drag to gain maximum speed, but the downforce required for the fast pair of turns and the slow last sector offset the straight by more than one would expect.

The circuit's kerbs were not too aggressive, being quite flat to the track surface but with the serration inset into the kerb rather than rising above it. This made riding the kerbs a little easier.

The brakes are used heavily into turn one, but thereafter the track opens up, giving them time to recover before sector three.

Lastly, as the track is some height above sea level, the engines struggle to produce the same power as at lower altitudes, but as the effect is the same for all teams no-one is disadvantaged.

China layout

As another of the new Tilke tracks, Shanghai reflects his other designs whereby a long straight is flanked by slow complexes with a few faster corners in the middle sector.

Following Fuji and with a similar layout, China's track has a lower grip surface, and the wet weather made the circuit extremely slippery.

Fortunately the rain was lighter and less prolonged, so the track dried to allow teams to run the harder tyre.

In the dry, the track's long corners degrade the tyres and the front left tyre suffers most, although as we saw, the rear tyres suffer from the low grip surface.

With such a mixed layout of fast turns, slow complexes in sectors one and two and the long straight, the track demands medium downforce and is quite easy on brakes and cooling.

Most teams engines are carried over from Fuji, where the cancelled sessions and wet race made their duty cycle lighter than usual.

Teams with engines on their second race in China will be able to fit an engine that only has to complete a single race for Brazil. Thus, the engines could be built to higher state of tune or allowed to run more revs, as they only have half their usual mileage to complete.

Wet set-up

The wet weather through Saturday and Sunday in Japan was the first real test of the current tyre rules. while the damp first stints in China further tested Bridgestone's wet tyre selection.

Bridgestone provided the two usual types of tyres; the lightly treaded intermediate now termed a 'wet' tyre and the deeper treaded tyre now known as an 'extreme wet'.

In Japan, the drying qualifying sessions showed the intermediate tyre to be ideal, although the tyre was at its best only for two timed laps.

After that the tread blocks would wear, and many teams switched to fresher (although scrubbed) intermediates for the timed laps after the fuel burn period.

In the race, we saw the unusual situation of the rain being at least constant and the track never really dried. Thus, the wet tyres were actually wearing, leading to teams having to change them at the pit stops.

In China we had a damp start to the race, and the slippery tarmac ensured that intermediates were the ideal tyre to start on.

As the rain came and went, the track never developed a fully dry line until mid-way through the race, so most teams opted to remain on the well-worn intermediates.

It's a strange conundrum that as the track dries, the worn intermediates work so well. It seems their compound is so much softer than the dry tyres that the tyre still grips in the wet, while the worn tread blocks do not generate too much heat.

Switching to fresh intermediates would soon cause the tyre to overheat from the internal movement generated in the taller tread blocks, while switching to slicks wouldn't allow enough heat to be generated to keep the tyre within its operating range.

So effective were the inters in China that some teams were able to go from them straight on to the harder compound slick tyre.

Bridgestone tend to prefer their wet tyres to be closely matched their dry tyres. Thus, their wet tyres are not as good in very wet conditions, but the gap between intermediate and slick tyres is closer.

Bridgestone feel that in very wet weather the cars will be behind a safety car and hence won't be racing at full speed. Last year this was evidenced by the Michelin superiority in wetter conditions, only for the situation to be reversed as the track dried, when Bridgestone's intermediates brought the lap times down to a pace where slicks could be fitted.

Some teams opted to alter their set-up for qualifying in Japan to suit the wet conditions. As so many parameters can be altered electronically, this largely involved softer springs and roll bars or more downforce.

Higher ride height used to be a wet set-up requirement, but the two wet tyres are now over a larger diameter, which saves the teams from raising the car.

This leaves items such as the severity of the throttle, gearshifts, engine overrun and differential locking to be adjusted from the steering wheel.

In China, the expectation was for only a small amount of rain and the teams did not favour the wet set-up as much as in Japan.

Team by team

Ferrari

Ferrari finally raced their new slotted pod wings in Japan. There have been two versions of the pod wing tested, one smaller version similar to the previous wing and a longer pod wing which was the version raced at Fuji.

As yet the team have not married the slotted pod wing to the slotted T-wing. The slot in the pod wing lets air from inside the plate to pass to the outside; the high-pressure current produced probably sweeps around the chimney to increase the efficient of the T-wing.

China also marked the debut of Ferrari's pit light system, which has been seen in testing and practice for several months.

The system takes the control of the car exiting the pit from the lollipop man and gives it to the staff on the pit wall. Lights on the overhead gantry signal to the driver that is safe to leave the pit.

This seems at first excessively complicated, but there might be some valid benefits from the set-up.

Firstly, the lollipop man has to observe the tyre changers, jack men and refueler completing their work, as well as keep an eye on the pit lane for oncoming cars.

By giving the control to the pit wall the team has a better view of the pit lane, but this is offset by a more restricted view of the pit crew at work.

Sensors noticed on the jacks suggests the car is rigged with sensors to detect the position of the jacks, and potentially the fuel nozzle and wheel nuts.

If the pit crew can get clear confirmation these tasks are complete, then the car could be released fractionally quicker and without fear of the wheels or fuelling not being completed.

The unit hangs from the same rail that provides the airline to the front-left wheel gun, although the unit appears quite low - the car's highest point is the camera pod, and this is barely more than a metre above the ground.

Inside the unit, there are a series of three traffic lights to dispatch the driver once stopped. Each light is made up from three individual LED bulbs to ensure they are visible even in bright sunlight.

There is a smaller series of lights on the reverse of the unit to warn the front jack man and other pit crew that the car about to leave the pit.

The car arrives in the pit with the light on red, then as the car needs to prepare to leave an amber light appears, then the green light gives the signal to go.

In the race in China, we saw Raikkonen leave the pit as the rig was still being lifted clear of the nozzle - such co-ordination would be unlikely with a manual system.

McLaren

McLaren continue to develop the car in their usual almost imperceptible way. For Japan, a revised front wing was used. This wing matches the profile of the existing wing, only the span is wider. This necessitated the endplates to be revised, with a narrower foot plate.

Another well-hidden change for Japan was a new fin on the front brake ducts. Since the FIA opened the brake duct area to allow non-cooling designs, many teams have fitted extra fins and vanes to the ducts.

McLaren's new version places an upwardly angled fin behind the inlet scoop. Its shape and position suggests that it is trying to send air into the low-pressure region behind the front wheel to reduce drag.

Toyota

Despite being so late in the season and with a large gap in the championships to their nearest rivals, Toyota produced a major update to the car for Fuji.

This update was commissioned as a special project for the Fuji race. The so-called 'Project Fuji' was aimed at producing a big step in the pace of the TF107 with the development of a new floor and wings.

Some of these updates have, in fact, been rolled out already as updates in recent races. The final developments released for Japan included the much-tested static front wheel fairings and diffuser, as well as revised turning vanes and rear wing.

The front wheel fairings follow Ferrari's pattern, with the fairing being attached by a bearing to the wheel nut. The inside of the fairing features an array of fences to guide the air out of the wheel.

The opening created at the rear of the fairing is a similar size to Ferrari's, but rotated backwards by about 30-degrees. These fairings reduce drag not only by streamlining the wheel, but by reducing the airflow thrown out sideways from the wheel and brakes.

This flow, which is normally seen as the black dust cloud thrown out under braking, is instead routed into the low-pressure region behind the front wheel.

As well as the wheel fairings the diffuser was new, with the central tunnel walls being revised to create a much more curled footplate. The change makes the footplate almost in line with the step along the bottom of the floor and help to seal the low pressure created by the central diffuser tunnel.

BMW Sauber

Several detail changes were made to the BMW Sauber over the two race weekends. In Japan, there were new Viking wings, with a revised shape where the fin bends and then new gurneys on the diffuser.

For China the team sported Ferrari-like flicks mounted under the main sidepod flip-ups. These changes were relatively easily bolted on to larger existing parts, enabling BMW to improve the car's performance without having to ship large body panels to the fly-away races ...

Honda

Having spent the season working on understanding their aerodynamic problems, ranging from the wind tunnel calibration to the actual design of the car's wings and surfaces, Honda appeared in the Jerez test with an interim test car.

Since Geoff Willis's first design input into the BAR team, as it was then, the team have run only small forward turning vanes, preferring not to run the larger rear pair of bargeboards.

Several other F1 technical directors point to the larger rear bargeboard as a key component in a top F1 car, even more important than the keel layout, as the bargeboard contribute so much to the flow under car to the diffuser.

Honda's new aero team, lead by Loic Bigois, trialled a revised RA107 without the pod wings and other add-ons, choosing just to run a simple large rear bargeboard.

This wasn't a serious attempt to produce a big leap in performance to be ready for Japan, but rather the first steps in assessing how the car responds to the different bargeboard layout.

Thus, the design was not optimised to the stage most other teams are with their boards, with the addition of axe heads, flip-ups and secondary forward vanes.

Not surprisingly, the drivers comments did not suggest the parts were an improvement, but the exercise was to gather data towards optimising the design for 2008.

Also during this test and also in Friday practice in Japan, Honda ran their bridge wing, similar in execution to the Williams Monza wing.

Again, the Honda nose is not as low as McLaren's, and the bridged section curves up much higher to step over the nose cone. It will be interesting to see whether teams have lower noses planned for next year's car to better exploit this bridged section.

Williams

As with Toyota, Williams have been testing static front wheel fairings, but are yet to race them. For Japan, the team produced a wider mid-wing fitted to the roll hoop.

Red Bull Technologies

For China, Both Red Bull racing and Torro Rosso sported a new fin on the rear impact structure. Unlike the pyramid-like shapes used on other cars, Red Bull's solution is a vertical fin simply blended into the rectangular impact structure.

Spyker

As part of the development of the B-spec car, the team had revised front and rear wings.

The new rear wing uses a twisted profile with a steep centre section, and end plates featuring four slots moulded near the beam wing mounting.

This feature is also sported by Ferrari, Renault and Red Bull. The slots reduce pressure at the tip of the beam wing by sending it through the slots to outside the endplate. At the front, the wing had a new deeper flap.

Elsewhere on the car, the pod wings made a return for China, having been deleted from the B-spec car at first. On the front suspension, the fairing around the front of the upper wishbone was been extended to sweep back almost to the rear leg of the wishbone.

Super Aguri

A tiny change adopted for both races was the addition of a small ramp-like extension above the rear light.

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