The trip to North America consists of two races just seven days apart in Montreal and Indianapolis and while, on the surface, there would appear to be little in common between the quirky Canadian Circuit Gilles Villeneuve, set on an island in the St. Lawrence Seaway and the famous Indianapolis Motor Speedway, where the Formula 1 cars race on part of the legendary oval track, from a car engineering viewpoint they share several similarities. Paolo Martinelli and John Iley, respectively head of Engines and Aerodynamics for Scuderia Ferrari Marlboro discuss the specific requirements of these two demanding circuits.

PAOLO MARTINELLI

Both drivers will be starting Canada with new engines and so they will have to deal with the demands of both North American weekends. "In Canada you need a combination of good aero efficiency, strong brakes and also a strong engine for good acceleration," begins Martinelli, outlining the prime requirements for the first of these two back-to-back weekends. "In terms of severity on the engine it is quite tough because there are frequent accelerations and a significantly long straight. And with Indy following it, it means we have two severe races one after the other - in this third of the season probably the most severe pair in terms of demands placed on the engine. We have put a great deal of effort into preparation for these two grands prix, with simulation on the dyno and track testing last week at Le Castellet, with a major test involving the race and test drivers and two cars. We did a long run to simulate as closely as possible the behaviour of the engine in the Canada and Indy races."

It will be the first time in many years that V8 engines will be raced at these tracks. "But we have specific software with which we can simulate complete car behaviour and so we can predict the revs, gear ratios and car settings before we get there," says Martinelli. "In addition, for the engine, we can also simulate quite accurately the race to come on the dyno. Specifically, comparing the V8 to the V10 from last year, the period of wide open throttle will be between 10 and 20% higher and even the medium revs will be up by 6 to 800 rpm which adds significantly more stress to moving parts in the engine such as pistons, valves and other components."

With two tough races to deal with, Martinelli is naturally cautious when pushed on the question of reliability. "At the start of the season, we encountered an unexpected technical problem with the new V8 engine which we had not predicted from the results of winter testing," he admitted. "We confronted this problem in the piston area, identified it and fixed this issue. Apart from that, we have had no significant problem in terms of reliability. Of course we are trying to improve continuously in terms of performance, even though the next two races are very severe. It is impossible to say we are one hundred percent safe in terms of reliability, because in Formula 1 the safety margin is really tiny, a 2 to 3% margin only in order to maintain the necessary level of engine performance. So our performance in North America will also depend on the conditions we encounter. There are several parameters. You can have a hot race where you want to run at the front so that no other cars impede the flow of air through your radiators. If the competition is very strong then you have to push hard for the entire duration of the event, from the first to the last lap which produces additional stress for the engine. We have to be prepared always for the worst case scenario. We have a mileage target of around 600 kilometres per event, made up of a 300 km race, plus qualifying and free practice, which is then multiplied by two to complete both races."

However, there is little one can do to "preserve" engine life over these two weekends. "Normally we can try and protect the engines in terms of revs and temperature during free practice on Friday and Saturday morning," says Martinelli. "While working on car set up, the last two to three hundred rpm are not vital. But in qualifying and the race you cannot protect the engine unless you are in the lead with a good margin, something we have not seen anyone enjoy this season! Canada and Indy are both tough but it is the combination of the two together that is the really tough aspect. Both circuits are demanding. The peculiarities of Canada, as I've said before are good efficiency and acceleration and hard braking.
 

"Indy however, combines the aspect of the very long straight with a banked corner so you keep the throttle wide open for over 20 seconds, maybe we can expect 22 seconds of full throttle, the longest of the championship. Then there is the infield, where in engine terms, you can relax a bit. Specific components, mainly the pistons, suffer from the continuous long straight and that is the critical area. We have prepared some new developments for these events which we have tested in Ricard and from what we have seen there we will introduce them as of the next race."

JOHN ILEY

Both Montreal and Indianapolis are circuits that require what can be called a medium drag package, when it comes to aerodynamics. "This involves a brand new rear wing assembly, some extensive modifications to our existing front wing assembly, refinements to the brake ducts, especially for Canada, where the circuit places the highest demands of the season on the brakes, so we have to be mindful of this," explains John Iley. With two less cylinders and a capacity drop, one would expect the current crop of engines to produce less power and therefore put less strain on brakes and their aerodynamic requirements, but apparently this is not the case. "With the V8 what is interesting is that because of the tyre development so far this year, the grip level has also increased quite a lot. Therefore, while we expected that lower power would mean lower top speeds which would affect the braking in a helpful way as we are braking from a lower top speed, this has not happened. In fact, the lower Cd level we can run is not helping in terms braking from an aerodynamic point of view and then, if you add the increased tyre grip, I think the braking distances and work for the brake system are even tougher now than last year."

The most radical changes are to the bodywork and wings as the aerodynamic package is generally optimised to suit the majority of the tracks on the calendar. "Therefore, for Canada and Indy you refine a lot of the areas so we have a whole new bodywork package as well. This was planned from before the start of the season, because I would estimate that 90% of this new package is circuit specific, with only the remaining 10% coming from our ongoing development and what we have learnt so far this season. We are really refining the car package for the two North American races. The biggest difference between these two tracks is the braking. The reason we can run lower drag is that at both circuits there is an absence of true high speed corners. Canada has a lot of chicanes, which put more of a premium on braking, stopping and change of direction. Indianapolis has one very high speed corner that is not demanding in terms of aerodynamics and is quite easy to drive flat out. It then has quite an arduous infield section which does not put much of a premium on the aero side. In this case, we are looking at reducing the drag, helping stability of the car under braking and having a good braking system."

The theoretical advantages of the car's aero package have to work in the real world on the track and at the races, it is up to the race engineers to use it as best they see fit. "We provide the aero range which the team can operate in during the weekend and then, in Indy for example, it's up to them to decide if they want to be lighter on downforce to be faster on the high speed section and compromise the infield or if they prefer to be the other way round. There are some areas where we can refine the behaviour of the package in terms of being good for both parts of the track, but that is just in small detail. This year we have had a big push on the overall efficiency of the car and I am happy to say that is reflected in the speed trap figures over the year so far and reflects on a very good job the department has done. That helps, as it means the compromise can be minimised as you can run high downforce for the infield section and still have very good straightline speed."