TECH TUESDAY: How AlphaTauri’s upgrade gives them a much-needed performance boost
AlphaTauri may be languishing at the bottom of the constructors championship but since the substantial upgrade of its AT04 car in Singapore two races ago, it is now performing at a higher level than the teams immediately above it in the points table. With six races left, the race is on to catch and overhaul the Alfa Romeo and Haas teams.
At both Singapore and Suzuka – two contrasting tracks – the AlphaTauri has made it into Q3, having done so in only two of the previous 14 races. Its average deficit to the front before the Singapore upgrade was 1.6s compared to 1.1s in the combined Singapore and Japan events.
IT’S RACE WEEK: 5 storylines we’re excited about ahead of the 2023 Qatar Grand Prix
The key to the powerful upgrade responsible for that performance boost – one of the most impressive from any team this season – was a completely redesigned floor. The floor is the absolute key to performance in the post-‘21 generation of car and teams are constantly seeking to find the ultimate geometry for the ground effect tunnels within them.
McLaren demonstrated earlier in the season with its transformative Austria upgrade that there are massive gains to be made there. This is the AlphaTauri equivalent.
Without detailed ‘before and after’ images of the underfloor, the changes in floor geometry can only be implied from those to the sidepods. The changes seen there are purely to facilitate the improvement in floor performance.
There are three key changes to the sidepod shape which suggest the floor changes.
The Sidepod Profile
The most visually obvious change is the new ‘hump’ on the sidepod’s top surface towards the front, just behind the radiator inlet. This replaces the previous smooth downwards contour and in creating more of a channel, prevents air from spilling over the side of the bodywork and interfering with the crucial airflow along the edges of the floor just above the ground.
Keeping these two flows separate plays an important part in the underfloor’s performance because the vortices created by the various cut-outs and the winglet there serve two vital functions: they help accelerate the air inside the tunnels and form a seal preventing the airflow going through the tunnels from simply leaking out the sides.
POINTS PERMUTATIONS: How Verstappen can become the 2023 F1 world champion in Qatar
Several other cars have a defined ‘water slide’ depression in that top surface to fulfil this function. The hump has been AlphaTauri’s solution to achieve the same without having to relocate much of the cooling system within.
There is a more subtle change in the upper body profile further back. It’s no longer a single smooth line, but swoops down then rises up at the back to accentuate the channel before then cutting off abruptly.
This will manipulate the air pressure in that region differently, probably with the aim of accelerating the airflow along the sides of the floor into the gap between the rear wheels and diffuser walls. The diffuser profile has also been changed.
.png.transform/9col-retina/image.png)
There is a more subtle change in the upper body profile further back. It’s no longer a single smooth line, but swoops down then rises up at the back to accentuate the channel before then cutting off abruptly.
This will manipulate the air pressure in that region differently, probably with the aim of accelerating the airflow along the sides of the floor into the gap between the rear wheels and diffuser walls. The diffuser profile has also been changed.
BARRETTO: What next for Liam Lawson after missing out on AlphaTauri seat for 2024?
The combination of a more powerful vortex generation along the floor edges with the more abruptly shaped sidepod tail should have helped with the lack of rear grip into slow corners the drivers have complained of through the season. Keeping this airflow energised as the car’s speed drops off, not having the flow simply break down, is crucial in generating low-speed corner performance.
Or, as AlphaTauri itself phrased it in the car update document of Singapore: “The forward floor edge changes lower the static pressure local to the floor edge and helps draw increased mass flow under the forward floor between the fences… the diffuser modifications enhance the strength of the rear floor edge vorticity, giving a local load gain within the diffuser.”
AlphaTauri’s car, pictured here in Japan, compared with the pre-Singapore car in picture two
Floor edge changes
The visible edges of the new floor are also substantially different. They surrender some of the permitted floor area at the front, but the losses from that will be more than gained by how the bigger cut-out should give a more powerful boost to the vortices created as the air tumbles down the undercut section of sidepod just above and begins spinning.
These vortices travel along the length of the floor edges, accelerating the adjacent airflow passing through the tunnels.
DRIVING STYLE: Yuki Tsunoda reveals his favourite brands, clothing essentials – and his must-have accessories
Forward tunnel profile
Complementing the new floor edge is a change in the lower edge of the front of the sidepod. The whole front has been lifted to give a more extreme downward slope of the tunnel.
At the front, that lip outlining the profile of the tunnel has been squeezed up closer to the ‘cannon’ section of bodywork above. Not only has this created a steeper initial downward slope for the tunnel but has given a bigger area around the external floor edges to help with propagating a more powerful vortex.
It’s still relatively early days, and the race day performance in both Singapore and Japan was compromised by strategic choices which didn’t work out. But the underlying performance boost of this upgrade suggests that AlphaTauri has more than a fighting chance of climbing from the bottom of the table.
