Ferrari's excellent SF70H car remains at the forefront of the F1 2017 pecking order - but has the team felt the effect from losing some of its more innovative solutions?
Ferrari's resurgence this season has been nothing short of miraculous, the team maximising its resources to produce a stunning machine, one that could deliver the Scuderia its first championship in a decade.
The SF70H features numerous innovative solutions, including but not limited to: a novel sidepod and side impact spar arrangement, a return to the longer, more intricate ‘S’ duct - similar to a design last used by the team in 2008 - and a floor solution which grabbed several teams' attention at the beginning of the season.
This is a welcomed change in ethos from Ferrari, as many considered the team to be far too cautious in the last few years. The designers were seen as seemingly locked into a rigid mindset, unable to find and operate in the grey areas that their rivals have exploited.
Pushing those boundaries has inevitably led to the SF70H being put under the microscope and the Scuderia has been pegged back, some of its more fanciful toys quietly taken away.
This, along with a development push by Mercedes, has allowed the Silver Arrows to re-enter the fray, setting up a fascinating technical battle when the teams return after the summer break.
Ferrari has been utilising a blown axle since 2015 (above), as it can, in combination with the front wing, assist in smoothing and controlling the movement of airflow around the front wheel.
Air taken in by the brake scoop inlet travels through the hollow axle and is pushed out the end, with a static carbon nozzle used to influence its direction and shape.
From a historical perspective the wheel rim covers that proliferated the cars in the late noughties offered a similar effect, displacing the turbulent wake generated around the wheel rim in order to improve the performance of the floor downstream.
The banning of these covers from 2010 saw several different connotations of the core concept, with Red Bull pushing development in the area.
The RB8 featured one such clever interpretation, as holes placed in the axle allowed air collected by the brake inlet to escape through another set of holes housed in the wheel.
Both were designed in such a way that the rotation of the air released by these holes assisted in controlling the turbulent wake generated by the tyre, improving the performance of the floor and diffuser downstream.
The car ran in this configuration at the first race in Australia all the way through until the seventh round in Canada, when a request for clarification from several other teams forced the FIA to intervene.
Once it had taken a detailed look at the axle's secondary aerodynamic function, the FIA deemed it a ‘moveable aerodynamic device’ and the team was forced to return to a standard axle for the remainder of the season.
Around the same time as Red Bull’s solution was in use, McLaren had been developing a system for the MP4-27 that allowed the team to adjust the rear brakes during a pit-stop, something that would still be considered legal today.
The crux of the system lay in the opening and closing of a window in the drum, as a mechanic adjusted a bolt on the engine cover. This allowed for more heat to be extracted from the brakes if that were needed during the next stint of the race.
Although this is clearly a very clever system, it was deemed to be overkill, as it also weighed significantly more than the standard system and was rarely used.
Even though Red Bull is recognised as the leader in this area of development, it was actually Williams that introduced the first version of what we now know as the blown axle, when in 2013 the FW35 was outfitted with a hollow axle that featured a stationary nozzle within.
Able to find the necessary performance advantage from it, numerous teams have utilized a blown axle in this configuration since 2013 - more so since the front wing's wingspan was reduced to 1650mm in 2014. A timeline of the concept's introduction is shown in the animation above.
It's well-documented that teams remove the blown axle at high-speed circuits such as Baku and Monza, either putting in a bung just as Haas did in 2016 (above) or returning to a standard stub axle.
This is because it’s detrimental to straightline speed, as while it helps to improve downforce when cornering, it can be particularly ‘draggy’ on the straights.
Having used a blown axle since 2015, Ferrari decided to push development into uncharted territories this year, as an attempt was made at being more aerodynamically efficient - shutting off the blowing effect when not needed.
The idea was to alter the car's aerodynamic behaviour while racing in order to have the best of both worlds at every circuit.
It’s understood that a fluidic switch, much like we saw deployed as part of the F-Duct system, was being used by Ferrari, as it looked to change whether the blown effect was on or off.
However, unlike the F-Duct that required the driver to block a hole in the cockpit, it’s understood it was as simple as whether the wheels were in a straight on or steered position, with some overlap for transition.
Since Baku, the team has continued to use the blown axle but the switching effect that had provided a performance boost has been nullified.
The FIA pressured the team into removing it, citing that, like Red Bull's 2012 version, it must be deemed by its very nature a moveable aerodynamic device.
The controversial floor
Up until the race in Baku, Ferrari had been utilising a large slot in the edge of the floor that resembled a scythe.
The slot had drawn attention from the other teams and the FIA, as it had been seen to flutter quite violently when loaded, bringing into question its aerodynamic credentials.
This type of movement is ordinarily detrimental to performance but there were suggestions that advancements in CFD and carbon production had made Ferrari question whether it could accurately model the deformation under certain conditions to capitalise on a multi-modal advantage - both downforce generation and drag reduction depending on the prevailing conditions.
The team had made numerous attempts to satisfy the FIA’s request to strengthen the floor and limit its ability to flutter, with a metal insert added at the slots opening (circled, inset).
This area of the car is not subject to any specific load tests but, as Ferrari failed to sufficiently pacify its rivals or the FIA and prove unequivocally that the floor wasn’t providing a performance advantage, it seems the catch-all article in the technical regulations (3.14) relating to moveable bodywork may have been called on.
As we can see in the main image, the team revised the design in Austria, closing the previously open-ended slot and adding a metal support to prohibit flexion.
The change may have been made in response to the loss of the switchable blown axle or as a consequence of further pressure from the FIA.
Either way, both items likely worked in unison to improve the performance of the floor and diffuser and wouldn't work as planned without the other.