The photo that offers clues about Mercedes’ F1 troubles

For however much its rivals believe the German car manufacturer is sandbagging, it was clear from observing the W13 on track that it is not in a happy place right now.

The excessive porpoising, lurid oversteer moments and struggles to find consistency through a corner have left it on the back foot.

But while there has been no detailed explanation yet about what its issues are, some late modifications to the car – including the drastic move of cutting away some of its floor structure – have offered us some clues about the team’s difficulties.

As our exclusive photograph (below) shows, late on Saturday Mercedes took the saw to the innermost underfloor strake, removing some of the lower edge, in an effort to change flow distribution out and across the forward section of the floor and into the underfloor and diffuser section.

Mercedes W13 detail

Photo by: Giorgio Piola

Their final few runs of the session were also completed with the W13’s underfloor having been doused with flo-viz, in order that it might get some visual confirmation of the competing flow structures and hope that it might provide some further feedback on the direction it might need to take to solve the ill effects that the phenomenon creates.

The move to cut the floor shows that Mercedes is trying to find a way to get rid of the porpoising problem without having to raise the ride height so much that it loses its peak downforce.

Trimming, refining and even adding details to certain areas of the floor appears to be the preferred way that Mercedes feels it can get its car in the right window.

Mercedes W13 floor comparison

Photo by: Giorgio Piola

The floor design, as a whole, is new and part of the package of parts introduced by the team at the beginning of the test alongside its radical sidepod concept.

And, where the team had previously had a more complex wave-like section on the front edge of the floor, it is now a little more simplified (red arrow).

What’s more, the design of the floor's edge could be considered simplistic when compared with some of its rivals, who might be using the geometry, allowable edge wing and some flexion to keep the floor's attitude more stable.

Meanwhile, Mercedes has been forced to add a metal stay, which prevents the entire floor edge from flexing too much (blue arrow), whereas on the Ferrari, below, this only really has authority over the section rear of the cutout and edge wing.

Ferrari F1-75 and McLaren MCL36 floor comparison

Photo by: Giorgio Piola

The last few runs also saw Mercedes run the car with more angle of attack applied on the front wing (you’ll note how steeply inclined the upper flap is relative to the adjustment points), in an effort to shift the car balance forward and put the car more on the nose.

This did seem to have the effect of making the car a little more pointier to help get rid of understeer and also raise the rear a little which could help with its bouncing issues.