The Scuderia have focused heavily on suspension geometry, internal aerodynamics and cooling over the past few races ahead of 2018, but a significant aero update was also prepared ahead of US/Mexico back-to-back weekend.
A new diffuser is at the centre of the update, which follows a similar design to that seen during the post-Hungary test back in August but not raced since. Whereas before there was a stepped central section, the revised area merges with the upper wall and is almost completely flush with it (yellow arrow).
This allows airflow to rise from beneath the car at a much greater angle, increasing expansion and inducing more upwash at the rear of the car. Additional ALM-made metal fins were also installed to the rear crash structure above to add to this effect (red arrows).
A more ramped central section requires more control over the air that is passing through it, so other areas have been adjusted to make this work properly. Turbulence ejected from the rear tyre into the diffuser’s side is managed by a series of scalloped slots along the SF70H’s floor, which in this latest update have been reduced from five to four and bunched closer together.
The front-wing was also given some attention: a tiny out-turned fin, joined to the back of the endplate by a slender strut, further pushes the air around the front tyre, drawing its wake away from the sidepods and bargeboards.