The eighth round of the World Championship takes place on the Ile Notre Dame, an island in the St. Lawrence Seaway, a short subway ride from the city of Montreal. The location was used for the Expo 67 world fair and the paddock backs onto a rowing basin built for the 1976 Olympic Games.
Hemmed in on all sides by water the facilities and the circuit itself are rather cramped, with the barriers very near the side of the track, which follows the perimeter of the island. This means it has some very high speed sections, linked by tight ninety degree corners and a couple of hairpins.
The Montreal circuit is known for being hard on engines and that will be particularly applicable this year as Scuderia Ferrari Marlboro and the majority of other teams will be tackling the Canadian event with the same engines that have already gone through a weekend's use at the Nurburgring. Montreal is not particularly demanding on the engine in terms of the percentage of the lap spent at full throttle, while the longest time spent at full throttle is pretty much the same as the season average. The stress comes from the fact that the circuit not only has some of the quickest sections of the year, it also has some of the slowest, so the perfect Montreal engine has to be very flexible at all speeds, while providing plenty of torque to power out of the tight slow corners.
Those corners lead to another key element at the 'Gilles Villeneuve' circuit – the brakes. "The fast nature of the circuit means we run in low aerodynamic downforce configuration, the lowest of the season apart from Monza," explains Luca Baldisserri, Scuderia Ferrari Marlboro's Head of Race Engineers. "Because of this we have to brake from very high speeds of around 340 km/h down to around 60 km/h, so the speed differential is huge. This is why it is very hard work for the brakes."
Unlike road cars that usually use steel brake discs and an organic pad material, F1 cars use carbon discs and carbon pads. The advantages of carbon are that the components are about half the weight of those made from conventional materials and it also offers a much higher coefficient of friction and therefore greater braking force.
The disadvantages are that the carbon set up requires very high (over 650 celsius) temperatures to operate properly and that the discs and pads wear out much more quickly than those made of conventional materials. This is because wear is caused not simply by the normal mechanism experienced by frictional material, but through a process of oxidisation where the carbon actually burns away. "In Canada, we try different materials, because we need a lot of bite from the brakes to stop the car in as short a time as possible," says Baldisserri. "The standard brakes we normally use at other tracks are less efficient and different materials can improve that characteristic. One must not forget the life of the components, as brake wear is an important factor for this race. We need to find a good material that gives a lot of bite but that will still work effectively throughout the whole race distance"
Canada is also known for being heavy on fuel consumption and obviously, carrying more fuel adds to the stresses already placed on the brakes, as a heavier car is harder to stop. Changes to the qualifying format introduced at the European GP might have an effect on this, as Baldisserri explains. "The rule requiring a driver to complete the race distance on one set of tyres definitely reduced the number of race pit-stops in the first part of the season, but, at the Nurburgring, with just the one qualifying session which cars contested using the fuel for the first stint of the race, we saw that some people were going back towards a more aggressive race strategy and stopping earlier as was the case last year. In Canada some teams might go in that direction, so as to run a lighter car. Depending on tyre performance, you can decide to be conservative or aggressive. Last year in Montreal for example, at Ferrari we had tyres that were not the fastest in terms of performance so we decided to go for a two stop race. Qualifying was not great but it was a successful race for us, with a one-two finish."
The whole braking process is complicated further by the laws of aerodynamics. When the driver first applies the brakes at very high speeds, the downforce generated by the car prevents the wheels from locking up, by pressing the wheels down onto the track. As the speed decreases so too does the downforce and therefore the amount of grip from the tyres. But this lack of grip coincides with the point at which the brakes are fully up to temperature and are working most effectively. This means that, when the brakes are at their best, the car is least able to transmit the braking forces to the road thus leading to locking wheels and the chance of skidding off the road.
In order to prevent this phenomenon, the cars can harness the braking characteristics of the engine. All 4-stroke engines produce engine braking when a driver lifts off the throttle, but F1 engineers can harness this ability to meet the specific needs of any braking situation. "We can modify engine braking, the amount of braking forces generated by the engine, during the braking phase," says Baldisserri. "This allows us to modulate the rear wheels locking. A lot of engine braking tends to lock the rear more and we can reduce that by opening the throttle without the driver having to do anything, as allowed by the rules. So depending if the front or the rear is locking up, we can either reduce or increase the engine braking. If the car is locking the fronts, we need more engine braking to reduce the amount of normal braking at the front. This is something the driver can adjust from the cockpit, in the same way as traction control, to suit individual corners on the track."
Although F1 brakes operate at high temperatures, heat is what causes the brakes to wear out and fail. The brakes are cooled by forcing air inside and around the discs through ducts at the front of the car. However, regulations restrict the size of these ducts and in any case, large ducts affect the car's performance in other ways. "You have to find a balance between cooling the brakes and the car's overall efficiency," maintains Baldisserri. "The brake cooling ducts have an effect on the aerodynamic efficiency of the car. In simple terms, the bigger the brake ducts, the worse the efficiency of the car, so we have to find the right compromise."
The conclusion is that, while Formula 1 is perceived as being all about speed and power, in Canada, being able to stop the car efficiently is the real secret to a quick lap.
