2007 Canadian GP Technical Review

It's hard to find two more different races adjacent on the calendar than the Monaco and Canadian Grands Prix. From Monaco's slow twisting streets to the fast open straights of Montreal, these two venues are as far removed from each other in their geographical location as they are in track layout and downforce and speed.

But for all their obvious differences, the two tracks do have some things in common. Both are semi permanent street courses, with a fresh un-rubbered track, and each place a demand on performance through slow corners.

This latter demand might seem irrelevant for Canada, but the cars only encounter long straights or tight corners in Montreal. The difference in Canada is that the cars aren't running the downforce to aid the grip through these corners.

In the tight fight for the championship between Ferrari and McLaren, this low speed grip demand has been the deciding factor in the rivals' relative performance. Back in Melbourne, Ferrari showed the upper hand in traction, while McLaren faltered. Since then, McLaren's new Mercedes engine specification and increased knowledge of the Bridgestone tyres has reversed this situation.

Lap times further suggest Ferrari are struggling for traction in slow corners on the softer tyres. Indeed, the supersoft tyres that were raced for the first time at the last two races have proven too soft for good race performance. After their initial boost in grip over the opening laps, they degrade rapidly. Therefore, most teams tried to minimise their effect by saving them for the last stint in the race when the surface is most rubbered.

Rear wing test

Following the on-board camera footage from Barcelona, where the rear wing of the Red Bull RB3 was seen to unduly flex at high speed, the FIA has further revised the rear wing deflection tests. Last year we saw a run of alterations to the tests to prevent teams flexing the flap and main plane for drag reduction on the straights.

In the case seen in Barcelona, though, the rear wing endplates appeared to fold and the whole upper wing pivot around the supporting struts. This would have reduced the angle of attack of the wing when loaded at high speed, reducing drag and improving straight-line speed, while in corners the lower load on the wing kept the wing upright. This produced the downforce needed for cornering.

But how did the wing meet the existing tests and still deform at high speed? The previous test pulled the wing directly backwards. This replicated the rearwards force created by the wing's drag, but in reality a wing sees both vertical (from downforce) and longitudinal (from drag) loads. It could be possible to design the wing's endplates and support struts to be strong enough for the old test and still deflect under the vertical load from downforce. Thus, the new test circumvents this by applying a downward load on the wing.

Kubica's Crash

Having to run wide around the left hand kink in the straight leading up to the hairpin to avoid Jarno Trulli, Robert Kubica ran over the kerb and was launched airborne.

When the BMW Sauber hit the wall, it was at a 30 degree angle and the FIA safety data logger recorded an impact of 28G. This impact compressed the nose cone and damaged the forward part of the tub, which mounted the steering rack, brake reservoirs and front wishbone mounts.

The impact would have made the slightly built Polish driver weigh over two tons. The load from his body would have stretched the seatbelts and Kubica's head, carrying a 1kg helmet (nominally 28kg at the peak of deceleration), would have extended forward - only being restrained by the HANS device.

As the impact was angled, the car's rear came around and the right hand sidepod impacted with the barrier. The block forming concrete wall was pushed back by this impact.

At this point the car was without any more significant protection to the front and the right hand side.

the car ricocheted off the wall, twisting in the process, the nose then digging into the grass, which set off the spinning motion across the track.

During this roll, Kubica's right rear wheel detached and the ancillaries to the right of the car flew off. The car rolled on to its roll hoops just before leaving the grass and jumped tail first across the track, landing on the floor and sliding around to hit the left hand barrier pretty much side on.

It was clear this lateral impact shook Kubica's head aggressively side to side, and his feet - now visible through the ruptured monocoque - were also shaken side to side.

Only the left rear wheel remained on the car when it came to rest. The side impact spars did their job but were now smashed; and the wings, sidepods and suspension were now scattered across the track.

Both the nature of the three impacts (hitting the smaller wall, the main wall and the left hand barrier) and the work the FIA has done with the teams to improve safety worked at all stages of this impact.

In the main impact, the long nose cone and the strength of the monocoque saved Kubica's feet by absorbing the energy and slowing the deceleration. While some criticism might be levelled at the monocoque failing around the front bulkhead, the shear enormity of the impact and the angled nose down attitude the car had when it hit the wall, are far beyond what the FIA tests the chassis for.

As the driver's feet are now well behind the front axle line, there is some 30cm of space between the driver and the front bulkhead, taken up only by the pedals and the front dampers. As a result, Kubica's feet were undamaged by the crumpling of the nose.

The other key effect of the main impact would be the extension to Kubica's body under the forward load. Quite literally, his body would have stretched from being subject to 28 times its own weight. This would affect his muscles and joints, but most critically his head and neck would have rolled forwards.

This movement was restrained by his HANS device, which couples his helmet via straps to the seat belts. This stops his neck extending too far and slows the deceleration of the head. Even without breaking a bone, this head and neck extension could have killed a driver in such an impact.

The secondary impact with the left hand barrier was thankfully to the side of the car, as the ferocity of the main impact had used up most of the impact resistance of the safety structures to the front and right hand side of the car.

This lateral impact could equally have damaged the driver's head and neck, as well as his feet and legs. The FIA foam inserts around the cockpit and inside the footwell saved his head and feet from impacting the chassis.

This special foam must be fitted at a thickness of 100mm on either side of the cockpit as well as a thinner layer to the insides of the monocoque from the dash to the pedals.

Monaco in brief

This year's race in the principality followed an intensive test at Paul Ricard for most teams. The test used track layouts to match those at both Monaco and Canada. Despite the two very different tracks, surprisingly both require the same pair of compounds from Bridgestone. For both races the soft and for the first time the supersoft tyres were raced.

As Monaco consists of largely slow corners, its main demand is for downforce. However with the lower powered 2.4l engines, the longer runs over the start/finish straight and through the tunnel mean that top speed does now affect the lap time.

This was never an issue with the v10 engines, whose surfeit of power allowed the teams to run bigger wings. As a result, Monaco is not the all-downforce festival is used to be. In fact this year few teams added a major amount of extra bodywork to suit the track.

With their usual neat wing-free design, Williams added more extra elements than most teams. The main sidepod flip ups received an extra winglet, while the mid wing was doubled up, having added the first for Barcelona. Additionally, at the rear they ran a McLaren-style flap in between the rear wing supports.

Like Williams, Toyota ran an extra set of mid-wings for downforce, as well as an extra flap on the pod wings. And, likewise, Super Aguri added a small flap to the inside of the pod wing.

At the same time, Honda released their major update earlier than the planned Canadian debut.

The revisions were tested at Paul Ricard and consist of revised sidepods and wings. The most noticeable change is the new sidepod arrangement; this sees the pod wings integrated into the chimneys as with the McLaren, allied to bigger undercuts on the fronts of sidepods.

This simpler arrangement is at odds with the complex set-up the car launched with and would be useful for rear downforce.

Also changed were the unusual paddle-shaped fins either side of the cockpit. These were switched for McLaren-like winglets placed just in line with the dash bulkhead. The changes improved the car; both drivers stated that handling and balance under braking were much improved.

Canada team by team

McLaren

McLaren alterations for Canada started at the rear with a new rear wing mounted revised supports. The supports are mounted further forward on the gearbox and reach back to mount the wing. As the wing has a shorter chord, the mounts wrap around the leading edge of the wing.

For the bigger wings to be used at subsequent races, it will be interesting to see if McLaren angled the supports upwards to meet the leading edge, or mount the wing under its middle.

Meanwhile the pod wings at the front of the sidepods received a slot to release the pressure on the inside face and sent it out the outside of the wing/chimney. What effect this would have is unclear; it might be a measure to reduce drag for Canada, or a more permanent alteration to the unusual pod wing/chimney arrangement.

Lastly, the fins mounted ahead of the cockpit made a return after being deleted for Barcelona. The new fins are shorter and devoid of endplates

Renault

Renault raced with a flatter front wing and revised rear at Montreal in order to move the car's downforce distribution around.

The rear wing sported a flat endplate, unlike the curved version usually run. The shelf wing in front of the rear wing introduced two races ago was deleted to cut down drag. With the shelf wing removed, the small flap attached to the crash structure - which was not on the early season version of the car - became visible.

At the front of the car, the nose saw a return of the two small winglets raced throughout last year. These were still mated to the horn-shaped fins further back along the monocoque.

Ferrari

At Paul Ricard testing, Ferrari tried running carbon-fibre wheel fairings on the front as well as the rear wheels. Two versions were tried in the Ricard test - one narrow rim, which was raced in Canada, and one fuller cover. This fuller cover has proved contentious and may not be raced.

The flat cover encloses the opening of the front wheel, but this fairing is static in relation to the wheel, which means that as the wheel rotates, the fairing remains stationary.

The fairing is attached to a mounting passed inside the hollow of the hub axle, and the heated air from the brakes passes out through a cutout in the lower rear of the fairing.

This design improves drag as the wheel is so enclosed, but this will come at the cost of brake cooling. However, the way air that flows around a spinning wheel may make use of the string flow eminating from under the front edge of the tyre, which spirals around the rear and tucks in behind the trailing face of the tyre.

This strong flow could actually help pull air from the duct, thus improving its efficiency. Of course, Ferrari's aerodynamic 'brake ducts' have roused complaints form other teams, and this more extreme version could equally be the cause of a protest at some point in the future.

For Canada, the Italian team also raced revised front and rear wings. The front wing was a simpler version of the conventional wing, while the rear wing sported a double dip across its span. Either side of the dips have less angle of attack and hence create less drag.

Honda

As part of their Friday practice runs, Honda tried a Renault-like rear wing endplate also raced last year in Canada. The wing blends the flap with the endplate to reduce drag created at the wing tip. In the end, the wing was not raced and a flat endplate was used.

BMW Sauber

As with Ferrari, BMW produced a rear wing with a double dip across its span. This was matched to the older format front wing and not the new squarer format wing raced in Spain and Monaco.

Williams

Unlike other teams, Williams produced a more conventional low drag wing package, with a simple twist to the rear wing profile and slimmer flap on the front wing.

Red Bull

Despite Adrian Newey's influence on the team, their rear wing package harked back to designs raced back in the team's days as Jaguar. The rear wing is made up of three distinct sections, with an angular break separating the inner and outer spans.

Toro Rosso

For the first time this season, Toro Rosso appeared to be able to produce the Red Bull technology designed wings at the same time as Red Bull Racing. This they raced with the bi-plane front wing and the angular low drag rear wing.

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