When Mercedes revealed its DAS system during pre-season testing, many expected its closest rivals to instantly go marching to the FIA to demand the system be banned. But whereas Red Bull has made clear it intends to protest Mercedes when racing action resumes, Ferrari has been far more sanguine about the affair – and indeed the team suggested it had looked at and rejected the DAS idea in the past.
Some questioned whether Ferrari was simply covering its back by those comments, but investigative work has now uncovered why the Italian outfit has not been so alarmed: because it has been running a system that mimics much of the benefits of DAS since the middle of last year.
In fact, as Motorsport.com can reveal, the concept – codenamed PAS (Power Assisted Steering) by insiders – has been so solid that it has been taken by Haas for its 2020 VF-20 car. While PAS is not as advanced as DAS, it was this type of system that Mercedes first began running from the start of 2019 and became the precursor to what it has developed for this year.
The W10’s power steering arrangement was equipped with a double rack and pinion setu-p, creating a variable Ackermann system that made it possible to make one wheel steer independently of the other, depending on the given steering input. In hindsight, the W10 seemed particularly agile and reactive in slow corners when compared with its predecessors, which was clearly a response to its new steering system.
This not only improved agility but also helped to keep the tyres in their optimum working range, lessening wear and improving performance.
Ferrari, having understood Mercedes concept relatively early on, decided to develop its own system, adopting PAS from the French GP onwards.
As it meant a larger, heavier and more complicated steering unit, there must have been more than one benefit to cancel out any drawbacks.
Having the ability to vary the Ackermann angle depending on the corner’s profile can have some interesting aerodynamic implications.
Given that the shape of the wake turbulence created by each wheel and tyre will also be altered according to path they draw, this could perhaps result in a similar wake profile across the board, allowing the overall aerodynamic map of the car to be tuned to increase downforce.
The timeline of the arrival of these variable Ackermann solutions shows how the introduction of DAS is an expansion of the original concept, allowing the driver to realign the steered wheels for the straights and eliminating any tyre scrub and/or drag that may occur when running even more aggressive Ackermann angles.
That Ferrari has made PAS available to Haas, proves that there must be good competitive benefits from it, and that the Italian outfit is fully comfortable with what it has produced.
DAS however, will have a limited shelf life, as Mercedes has agreed to uphold its ban in 2021 even though it’s likely that the chassis will have to be carried over from 2020.
This will come as a relief to many in the paddock who fear an escalation in costs will be detrimental to the sport in the wake of the impact caused by the coronavirus.
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