With illustrations by Giorgio Piola, Mark Hughes explains why the challenges of the Baku street circuit will put the spotlight on the so-called ‘flexi wings’ debate this weekend at the Azerbaijan Grand Prix.
Azerbaijan’s circuit in Baku features the most contrasting layout of the seasonal calendar. In terms of car demands, it’s an extreme compromise between the Monaco-esque mid-sector, which is all about slow cornering performance – braking, rotation, traction, drivability – and the massive 1.4-mile flat-out stretch along the kinks’ straight” which ends the lap and also occupies part of the first sector.
It’s a track that demands both Monaco and Monza wings, the two extremes of the season.
For this reason, the controversy surrounding the so-called “flexi-wings” could be played out at its fiercest this weekend. Because this race is not only the last before the new FIA measurement protocol came into force in France, but also the route on which the greatest use could be made of such a wing.
READ MORE: Flexi-Wings – What Are They And Why Is Everyone Talking About Them?
In Barcelona we saw Red Bull deploying their high downforce wing (bottom image below) throughout Friday practice. It was the wing that best protected the vulnerable rear tires by minimizing slide, which in turn better controlled their temperatures, which are always the defining issue at this track.
Picture above: The “spoon” wing | Picture below: The wing with high downforce
But after looking at the numbers, Red Bull decided that the high downforce wing made them too vulnerable at the end of the straight for the faster Mercedes, which is generally a lower drag car anyway.
So, starting Saturday, Red Bull reluctantly switched to its ‘spoon’ wing (top image above), which has had the outer sections of the underside cut away (circled in red above).
READ MORE: Verstappen predicts Mercedes will ‘come back strong’ in Azerbaijan as he targets maiden podium in Baku
The outer ends of the wing are the most drag-inducing part, so trimming them away is the most aero-efficient way to reduce a wing’s drag with the lowest cost to downforce.
But rearward-facing onboard cameras seemed to show that this particular wing had another drag-reducing benefit — moving down and back above a certain speed threshold when the aerodynamic forces acting on it became high enough to reveal that characteristic.
The middle sector of Baku is said to be “Monaco-like”.
The Red Bull wing has passed all FIA static load test requirements, but Mercedes boss Toto Wolff has indicated there could be protests if Red Bull – or any other team – decide to field such a wing in Baku.
The reduction in lap time that bending could bring at a conventional track would be small, but in Baku with that long straight – the longest flat-out stretch cars see all year round – it could be worth a more significant chunk.
Especially since the flex’s drag-dumping effect could allow you to run a higher wing angle, which pays dividends in the Monaco-like mid sector (which accounts for over 40% of the lap).
READ MORE: Why Red Bull’s pace in 2021 is more than the regulation changes
Thanks to Baku’s long straights, wing settings could make a big difference this weekend
The Red Bull’s high-rake concept is inherently more sluggish than the Mercedes’ low-rake, and typically the Mercedes has been quicker through the speed traps this season.
READ MORE: Have the 2021 rule changes shifted the advantage from Mercedes to Red Bull?
The motivation for Red Bull to attack this weakness of their car is very apparent as such a wing would likely give the Red Bull more lap time gain than a Mercedes due to more drag to be vented.
Historically, Red Bull has favored a low-drag approach at Baku. But in general, a high-downforce wing that prioritizes slow cornering performance can work here as well, with a very similar lap time delivered in a different way.
So it could be that Red Bull prefers their high-downforce wing anyway, especially when it offers significantly better tire performance. But interest in their choice will certainly be great.
