Revealed: The major Ferrari change being trialled at private F1 test

Ferrari is present at the Mugello Circuit on Thursday as it carries out a filming day with the SF-25 - the second of two permitted during the season.

In use at the short outing is the modified rear suspension, with the team allowed to conduct 200km of running during the day.

Both Charles Leclerc and Lewis Hamilton are present at Mugello, marking their first experience with the crucial development at Ferrari.

The new suspension involves moving the front attachment point of the suspension's upper triangle down. 

The intention of this modification, which is not small or trivial, is due to the need to determine whether the carbon fibre structure covering the gearbox is capable of withstanding the loads generated at the new attachment point of the suspension.

It was important to evaluate the suspension's behaviour ahead of the Belgian Grand Prix in one week's time, where it is set to be rolled out across the weekend. 

The modification became necessary after the findings from the first races of an inability of the rear suspension in its original version to work with the front end, which is made by the pull-rod suspension. 

It is therefore correct to consider that the new version aims to extract maximum potential from the latest aerodynamic changes that preceded the new suspension. 

This includes the floor trialled in Austria that also had positive feedback last time out at Silverstone, although not to the extent of undoing all of the SF-25's problems.

It is worth reiterating that the engineers headed by Loic Serra are also currently engaged in the evaluation and implementation of modifications at the hydraulic level of the SF-25's power steering.

At Silverstone, both Leclerc and Hamilton complained about the precision of the steering and the confidence in the stability of the front end in fast corners. 

It is an element that mainly affects the ability to set ideal trajectories at top speeds, without fearing sudden deviations of the car's front end.

If the rear suspension were to give positive feedback, it would represent the solution to the SF-25's excessive sensitivity at the aerodynamic performance level to changes in ground clearance and finally be able to extract the performance locked within the car.

The significantly less awkward power steering modification, on the other hand, should be completed in time for Hungary before the summer break.

The tests at Mugello will see the adoption of a wide range of setups to evaluate the dynamic response of the car, including on the long main straight, where the load generated by the bottom according to the ride heights adopted varies significantly. 

The new version of the suspension represents a litmus test of the SF-25's competitiveness in the second half of the season. But, at least until Spa, judgment is can be reserved!