Technical F1 Unlocked
TECH TUESDAY: The main factors behind Red Bull’s Singapore slump and how they bounced back in style at Suzuka
Red Bull’s spectacular fall from domination in Singapore and its equally spectacular return to form in Suzuka has highlighted just how hyper-sensitive this generation of cars are to set-up – specifically regarding ride height.
The ground effect principle by which these cars generate a big proportion of their total downforce is dramatically more effective the closer the lowest point of the floor is to the ground, until it becomes so low that the airflow stalls.
The ride height of the car as it sits stationary in the garage is just the foundation for the actual ride heights the car will see when out on the track. Downforce generally squares with speed and as that speed and downforce increases, the car is forced lower on its suspension, rising again as the speed reduces.
There are also the effects on ride height of roll as the car corners, diving as it brakes and pitching as it accelerates, plus any bumps or kerbs which must be absorbed.
The team will set the static ride height as low as it can to maximise the downforce, but different tracks impose different practical limitations to how low that can be.
There is a further potential limitation – that of the regulation underfloor plank. This is there to prevent teams running their cars dangerously low and was introduced after the fatal accidents of Imola 1994. The plank runs up the middle of the centre of the floor and is 10mm deep. There must be at least 9mm of plank depth remaining at the end of the race.
For most teams the plank does not usually impose their minimum ride height because they run into aerodynamic problems of bouncing or porpoising before then.
The stall point of the venturi tunnels tends to be at a higher ride height than the minimum the plank would impose. But not always on the Red Bull. Part of the RB19’s aerodynamic superiority over the field is how its combination of tunnel and rear suspension design allows it to run a lower ride height at speed without inducing porpoising.
At Spa – where the combination of Eau Rouge’s speed and compression exerts huge force on the car – Red Bull had to instruct Max Verstappen and Sergio Perez to back off each lap at that critical point in order to not excessively ground the plank. That way, they could retain the low ride height which bought them so much performance in the rest of the lap.
Around both Baku and Monaco, street circuits where the bumps and cambers all around the length of the track impose a relatively big ride height, the Red Bull’s advantage was smaller than elsewhere.
Any track demanding a big ride height hurts the Red Bull disproportionately, as does any circuit with short corners – such as at most street tracks – as it punishes the Red Bull’s reluctance to quickly generate front tyre temperature. So, at Baku it lost out on pole to Ferrari while at Monaco Verstappen was only just able to edge out Fernando Alonso’s Aston Martin.
Singapore, another relatively bumpy street track, was expected to be similarly challenging. In anticipation of the bumps and the front tyre warm-up issue, Red Bull brought a softer suspension. There was also a new floor which was part of the ongoing car development and not Singapore-specific. The changes to the vortex generators on the floor edges were just the visible parts of the new floor which also included a reshaped diffuser wall.
Notably, this was the first race at which a tighter definition of Technical Directives 18 and 34 applied, the latter specifically addressing the underfloor and the mounting of the plank.
During Friday practice the softer suspension was found to be unsuitable when running with the chosen ride height. Bumps in part of the track had been smoothed out with a resurface but other parts remained bumpy and the Red Bull seemed to have problems accommodating the contrasting demands.
To take the complicating factor of the new floor out of understanding where the problems lay, they reverted to the old floor from Saturday onwards, with the intention to revisit that question in Suzuka. As well as the floor change, the suspension was stiffened for Saturday FP3 and, while this reduced the bottoming and brake locking, it reduced rear grip even further and made generating tyre temperature more difficult.
With the car in this form it was within 0.3s of the Ferrari. For qualifying the team made further changes, including lowering the ride height. It proved to be a disastrous move and neither driver was able to graduate from Q2.
In summary, the Red Bull appeared to lose a bigger proportion of its usual downforce than other cars when its ride height was raised to cope with the demands of the track. This was then compounded by the set-up choices made.
A few days later, around Suzuka, a conventional racetrack with a much flatter surface, that problem dissolved and the RB19 returned to its usual form.
For the first practice session Red Bull conducted a back-to-back test between its two floors, with Perez on the old one which had been raced on both cars in Singapore and Verstappen on the new one which had been discarded in Singapore after Friday. This was just a precaution to confirm that the new floor did not have an undiagnosed problem and had not been part of the Singapore under-performance.
Verstappen dominated the first practice session in Suzuka and so the new floor was fitted also to Perez’s car for the rest of the weekend. Perez went significantly quicker with the new floor than he had with the old one, finally confirming that F1’s fastest car had been made even faster.