McLaren and Honda’s power unit struggles continued in Malaysia, but the team haven’t stopped bringing aerodynamic upgrades in an effort to move forward.
In Malaysia, the Woking outfit introduced an ‘S-duct’ similar to that originally developed by Sauber and then copied by Red Bull and Force India.
The only difference with McLaren’s, is that it uses two outlets either side of the pitot tube housing (see below) built within the vanity panel (white), whilst their rivals use just the one.
The aim of the ‘S-duct’ is to feed air from underneath the nose [1], by adding a duct under the nose, which is then fed through a channel [2] where it then exits over the chassis [3].
The main purpose is to reduce the boundary layer, which is a build-up of airflow under the nose ahead of the splitter, as this slows down the airflow around it, therefore making it less effective when it finally reaches the diffuser.
The slot allows this “stuck” airflow an escape route. A secondary benefit of having it exit over the top of the chassis is flow attachment. Normally airflow running over the nose detaches and causes lift. The high-speed air exiting the ‘S-duct’ draws this detached air back to the surface, increasing performance.
