At the Turkish Grand prix two weeks ago Ferrari had more than a comfortable advantage over their rivals. The scarlet cars were ultimately seven tenths of a second per lap quicker than the McLarens. However, at yesterday’s Italian Grand Prix McLaren had not only clawed back the deficit but had a car that was half a second quicker. This massive gain in performance after only two weeks is astonishing. The pendulum has been swinging between Ferrari and McLaren throughout the season but this is the single biggest turnaround in pace we have seen all year.
So how did McLaren do it?
The answer is quite simple. All of the teams raced with brand new aerodynamics at the Italian Grand Prix and McLaren package was better than Ferrari’s.
Now that Hockenheim has been shortened by Herman Tilke, Monza is the only superfast circuit remaining in Formula One. Drivers regularly exceed speeds of over 340kph and the track holds the record for the fastest race of all time. Due to the high speed nature of the Italian Grand Prix teams are forced to construct special one-off aerodynamic packages that only appear at Monza. It gives struggling teams a chance to make up some ground on the front-runners.
The technical challenge of developing a car for Monza centres on the amount of drag it creates. Whenever a car produces the aerodynamic downforce that provides grip around corners, it also creates drag that slows it in a straight line. At every Grand Prix the engineers have to set up the car to ensure the balance between downforce and drag is just right. At most circuits the team that can generate the most downforce with the least amount of drag will have the competitive edge.
The scenario at Monza is entirely different. Everyone configures their cars to run with almost zero downforce so the field is levelled out a little. The two factors that most impact performance are drag and engine power.
In 2007 all of the engines are homologated and limited to 19000rpm, so the difference between top speeds has been reduced. This means the reason that McLaren were able to get the jump on Ferrari is down to the efficiency of their aerodynamic package in the low-drag configuration.
McLarens dominance was no surprise given the amount of effort they put into maximising their performance. The British team changed almost every part of their car’s bodywork and although it may have been frustrating that all that effort was being focussed on only one race, it was worth it. McLaren’s outright speed was a direct result of the effort put in by their aerodynamicists.
It is very interesting to see what McLaren did and how their approach differed to that of Ferrari.
Firstly, McLaren removed the upper element of their front wing. From the Spanish Grand Prix onwards McLaren have had part of their front wing run over the top of the nosecone rather than below it. This component of the wing is not intended to generate downforce but is instead designed to sculpt the airflow around the nose of the car. Other winglets behind the front wing will then push the sculpted air into the radiators to maximise cooling.
Red Bull used this ‘overlapping’ front wing for the first time at Turkey but also removed it for the Italian Grand Prix. The reason that both McLaren and Red Bull ditched this element from their wings is because both teams were simplifying the movement of air around the car as much as possible. Everything that could potentially add drag for little gain was taken away.
To compensate for this change, McLaren slightly altered the way their front wing was attached to the nosecone so the mountings would provide more of a guiding effect on the airflow.
With that in mind it is rather interesting that Red Bull’s sister outfit, Scuderia Toro Rosso, used the ‘overlapping’ front wing for the first time at Monza. They calculated the cooling benefit of the air pushed towards the radiators outweighed the drag produced by the upper element. This would indicate the Ferrari engine used by Toro Rosso suffers more cooling issues than its rivals.
Not surprisingly this is evident on the Ferrari also. You may notice that the red cars have large slots cut into the top of their bodywork to release as much of the hot air away from the radiators as possible. McLaren have no such need for these cooling measures and could therefore use a low-drag front wing that did not force air into the sidepods.
Ferrari’s approach to front wing development was far different. They did not drastically alter the profile of their wing but instead raised the middle of it away from the ground. The rules state the front wing must be 150mm above the track surface but the centre of it can be a little bit lower. The teams therefore run the middle of the front wing as low as possible because it generates more downforce the closer it is to the ground. Since downforce is not an issue at Monza many of the teams raise the middle of their front wings to clean up the airflow around the wheels, and that is exactly what Ferrari did.
Changing the aerodynamics at the front of the car has a logical effect on everything else.
McLaren made significant changes to the winglets that appear on the side of the cockpit. Just like the upper profile of the front wing, they are not used to generate downforce but are instead designed to guide air into the radiators. At Monza these were mounted lower and closer to the sidepods to account for the new front wing. The shape of these winglets was also different and they more closely matched those used by Ferrari.
McLaren also removed some of the winglets usually found on top of their sidepods. The purpose of these is to direct air towards the rear wing which is responsible for about a third of the car’s downforce. Without the need for the rear wing to generate this downforce, the air flowing over it was no longer crucial and the sidepod winglets could be discarded.
The rear of the car was also radically different for McLaren at Monza. For the second year in a row the team decided to run a single element rear wing.
Throughout the season teams will have two elements in their rear wings (as allowed by the rules). Both of these are used to increase downforce but this means they also increase drag. Most of the teams will change the shape of their two elements at Monza, but McLaren ended up removing one of them altogether.
Ferrari did not.
Rather interestingly, Red Bull introduced an anti-drag measure in Hungary that did not appear on their cars this weekend. The middle of the rear wing is the least efficient part because the air running over it has been disturbed by the airbox in front. Since the ratio of drag to downforce on that section of the wing is most unfavourable Red Bull cut a piece of it out. They figured it wasn’t generating that much downforce so they may as well get rid of it and save on drag. This was a very simple and clever idea from Adrian Newey but they did not use it at Monza because the rear wing wasn’t generating much downforce anyway.
The changes that McLaren made served them very well and they went on to dominate the entire weekend. It was just reward for the many hours of hard work back at the factory.
The most testing Grand Prix for the aerodynamic boffins is now out of the way, but the biggest challenge for the engine men will come in only six days. At the Belgian Grand Prix both McLarens will be using the same powerplants they used in Italy. Monza and Spa Francorchamps are the two hardest circuits on engines so the Mercedes componentry will be under enormous strain during the next race.
The McLaren aerodynamicists proved their worth at Monza and delivered the team a healthy advantage. This coming weekend we will find out if the engine men at Mercedes have done the same.