2006 Canadian GP Technical Review

Canada serves the Formula One calendar as the first track where top speed is of overriding importance. Some of the other high-speed tracks have been modified (Hockenheim, for example) or now require higher amounts of downforce to cope with newly installed chicanes. This leaves only Montreal and Monza matching in their exceptionally high demand on the F1 cars.

The circuit Gilles Villeneuve is a semi-permanent facility and is formed largely of straights interconnected with chicanes and hairpins. There are no major corners to be taken at speed, and as a result the track doesn't require large amounts of downforce and rewards top speed.

For this race, teams aim to run the minimum downforce in order to maintain fast speeds on the two straights, leaving only downforce to cope with the heavy braking and to maintain some balance in the car's handling. To achieve this, teams used to develop a major upgrade for these low downforce races, but nowadays they are happier to revise the rear wing elements and front wing flap, both of which are flattened out to produce a lot less downforce.

Other aerodynamic devices on the cars are often removed, such as extra flip-ups and fins mounted around the car. This reduces the unwanted drag these items create. Furthermore, the weather can get very hot, which complicates the aero set-up, and for this race a lot of the teams have also added cooling vents in the top of the chassis to introduce a bit of cooling for the driver, who is sat amongst the power steering rack and electronic boxes.

Due to the straights, the track has a large percentage of "open throttle" running around the lap, and this makes the track demanding on the engines. Unsurprisingly, some 14 cars started this weekend with an unused engine.

With the high top speeds and low speed corners, it is the brakes that perhaps are meted with the most abuse this weekend. Several stops from high speed - and in particular the braking zone into the hairpin from around 200mph - see brake wear at its highest all year.

With the softer tyres and improved aerodynamics on the V8-engined cars, the brakes were under extra pressure this year, complicated by the new qualifying format, meaning top ten qualifiers need to run as much as 12 laps more than in previous years.

Being located in a windy river way, the track often collects a lot of debris mainly in the form of litter to clog the cars' sidepod inlets. But this year the softer tyres and unusually hot weather saw unusually high amount of marbles being accumulated around the track.

Marbles are the small balls of rubber kicked off by the tyres when the car is working hard through a corner. Hence, they tend to be shed when the car is either braking heavily or being pushed through a fast corner. As Montreal does not have any fast corners, the marbles were collected in the braking zones around the hairpin and chicanes.

In the latter stages of the race, the track surface was black with marbles to the detriment of the cars' grip, should they go off line. In the race, this situation affected every runner and ended the races of unfortunate few.

There is no cure for marbles under the current rules, as the grooved tyres and soft compounds conspire to make the tyres prone to shedding some rubber under load. Only the introduction of a single tyre supplier and a return to harder compounds will see this issue resolved.

Rear wing element support

After the scandal surrounding Ferrari's supposed flexible wings earlier this season, the FIA chose Canada to be the race where supports to maintain a slot gap were to become mandatory. Most felt the introduction of a device to span the two elements of the rear wing would bring an end to the dubious practice of having wings flex at speed to reduce drag in order to increase top speed.

However, as with most FIA proposals rushed in to prevent a practice that some teams would be loathed to give up, the initial ruling as to what the support should consist of was insufficient. Hence, the teams' design interpretations of their supports were wide-ranging.

Most teams opted for a small bracket spanning the main element and the flap - the support was sighted close to the slot gap and would appear to be a clear way of keeping the slot gap consistent. Some teams' interpretation were a little more liberal but no less effective.

Two teams sported much larger supports. By making their new wing support very big, it doesn't attach until half along the front of the wing, which misses a large part of the rear wing that can still be allowed to flex (opening the slot gap).

The opening of the slot gap at speed is a good way of cutting downforce and hence drag. The larger slot bleeds air from above the wing, which reduces the load on the flap. This in itself cuts both downforce and the vortices produced behind the wing.

Opening of the slot gaps has been used in recent years at the time when the forward element of the rear wing was not subject to any specific deflection test, and by drooping this element, the slot gap could open. The FIA stepped in and introduced the pull-down test under the rear wing's main element.

When this loophole was closed, teams moved towards the less efficient method of closing the slot gap. To do this, the teams flexed the forward edge of the rear flap to close the gap. Again, the FIA have stepped in, and the enforcement of a slot gap with a support has been introduced.

This support (light grey) must keep the rear flap in a fixed relationship to the main element of the rear wing. Some teams have made this support join the main element quite far forward. It could be possible to flex the remaining rear part of the main element (yellow); this could open the slot gap at speed (red lines), while meeting the FIA pull-down test.

Protests were nearly lodged against the BMW Sauber wing in Montreal, and photographs were circulated around the paddock suggesting their wing was flexing in just such a manner.

As the wing passed the only tests the FIA has available at the moment, the governing body had to accept the wings as being legal. However, a clarification could be expected soon as to what these supports should be like and how they must be seen to work.

Renault

Numerous changes on the Renault include shoulder fins (blue) and larger nose wings (yellow) © Scarborough (Click image to enlarge)

Renault appeared in Canada with updates for this specific race, and with some general updates that will be used beyond the American races. Most visible were the revised fins over the front suspension and the shoulder wings.

The nose fins are enlarged versions of these seen all year, but these are split into two. It appears the split is both to create a slot gap in the more aggressive profile, but also to accommodate the removal of the nose cone, as the fin spans both the monocoque and removable nose.

The shoulder fins are similar to the earlier Honda designs, and as such they are more an endplate than a wing. This is the first application of these devices on a car with extremely shaped sidepods.

In some respects, these developments seem counter-productive for Canada, as they are aimed at collecting up the flow upset by the front wing and guiding it downwards and around the sidepods. But as the low drag front wing has a smaller influence than is usual, these devices may have unnecessarily complicated the car's aero.

This is especially notable when we consider the changes made to reduce drag on the Montreal circuit. Renault changed the front wing flap and deleted the cascade wings on the endplates; on the sidepods, the winglets lost their slot gap, and the rear wing used both flat endplates and flaps.

Williams

The simpler flip up set up (yellow) on the Williams shows the broad gearbox fairing © Scarborough (Click image to enlarge)

Williams also arrived with a major update to their car. The team have been struggling aerodynamically all season, and although they have the downforce to match the other teams, this is not with the same level of efficiency, and hence the car creates more drag.

This is how the team were able to perform well at the mechanically-biased Monaco race and fall from competitiveness at Silverstone, a much more aerodynamically focused circuit.

However, Williams's second wind tunnel now appears to be reaping results, and the team had changes to the wings, floors and sidepods in Montreal.

Even though the wing profiles were specific to Canada and the other forthcoming low drag races, it's clear the front wing is similar to those used before with a simple curved two element profile. Above the front wing and attached to the nose cone, Williams adopted a pair of fins to control the flow over the wing.

On the rear wing endplate, a horizontal strake (yellow) has been added towards the trailing edge, while the sidepods lost their usual set-up flip-ups between the chimney/winglet and main flip-up.

With these devices deleted, probably to reduce drag, we can get a clearer view of the shaping introduced earlier this season to the gearbox and rear suspension cover. This is now unusually wide and forms a wing profile (yellow) around the area where the pushrod meets the gearbox.

Honda

Renault influence is seen on both the rear wing and sidepod winglets © Scarborough (Click image to enlarge)

Honda's main development was their interpretation of the Renault format rear wing endplate. As with Renault, Honda have integrated the flap (yellow) and end plate in a manner that reduced drag created by vortices at the wing tips.

By bleeding some higher pressure air coming off the wing through the gap created by the curved flap, the pressure differential is lower, and a weaker vortex is created.

Honda have supplemented the merge flap/endplate with two slots in the endplate, serving similar drag-reducing roles.

For the Canadian race, the wing sported a dramatic stepped profile with the middle section being much flatter, leaving the steeper outer sections to create the most downforce.

A smaller change was to the small winglets mounted to the sidepods (yellow). These no longer sported endplates on their inner faces, instead the flap was folded down slightly; again, this would have cleaned up the flow to the rear wing and reduced drag.