Monza is super fast, basically consisting of a series of long straights separated by tight chicanes and one or two fast corners – including the famous 180-degree Parabolica. Last weekend, speeds topped 340km/h, with Sauber driver Esteban Gutierrez fastest on Sunday at 341.1km/h.
Most teams aim to reduce downforce as much as possible (some have even run without a rear wing in the past) and it all starts with the rear wing design.
To understand why they do what they do, you need to go back to basics.
A wing develops downforce by having differently curved upper and lower surfaces, and by the angle at which it sits in the airflow. The laws of aerodynamics state that the air particles separated at the wing’s leading edge must re-join at the trailing edge and with different distances to travel over the top and bottom surfaces those particles must travel at different speeds.
As speed is inversely related to pressure the molecules going the long way under the wing travel faster and have a lower pressure than the ones going over the top - and that results in a net downforce.
This comes at the cost of drag that slows the car down – with the frontal obstruction of the wing causing some amount of drag and a portion of the downforce adding to that because not all of the downforce acts directly downwards.
So in Monza, the teams try to run slimline, flat rear wings to reduce downforce.
This year, they considered two rear wing options – a full-cord (the front to back measurement) with a thinner profile running flatter than normal or a half-cord main plane run at a very shallow angle and a rear flap of similar size run at a steeper angle.
The former created a basic low downforce set-up while the latter gave more downforce but could drop the drag to a lot less when DRS was in use on the straight (although this only works following another car).
Some teams also ran simplified, shallower, beam wings – the lower wing at the rear – and also removed any winglets from that region.
From there it’s all about balancing the rest of the aerodynamic package – mainly the front wing - to suit the downforce levels and optimising braking stability, which is crucial given the massive decelerations required for each of the chicanes.
The intricacies of modern F1 front wings allowed teams a number of different options here.
Most are now made up of a number of small flaps – up to seven in some cases – to deliver downforce and also have a series of upper cascade elements connected to the end-place which add downforce but also crucially control the trailing air to steer it round the front wheels.
To reduce downforce at the front, the teams can either reduce the number of flaps or make them flatter, or they can shorten the width of the cascade elements or remove them altogether. Some also add vertical strakes to create vortices that help with wake management.
Red Bull have such an efficient baseline downforce that they were able to drop all the less efficient add-on parts they use at other races and end up with a highly efficient standard low-drag set-up which still delivered a decent level of downforce without too much added drag.
That saw them use a shallower full plane at the rear and drop an upper flap at the front. Added to a longer seventh gear, it made them faster than normal on the straight but still gave them enough downforce to be strong in the faster corners.
This was of particular advantage in the Parabolica, as being fast there they had a fast exit speed and could carry that all the way down the straight.
Ferrari tried a drafting technique in qualifying – with one car driving ahead of the other to give them an advantage – but that failed when Felipe Massa was not able to give Fernando Alonso the tow he needed.
So Vettel took pole easily – a crucial factor to make the higher downforce package work - and after that, apart from slight gearbox worries, the rest was easy...