How Red Bull have found their wings again in 2015
Sky F1's Mark Hughes reveals how Red Bull have returned to competitiveness after a series of subtle changes to their 2015 car...
Last Updated: 30/07/15 8:06am
Red Bull enjoyed by far its strongest performance of the 2015 season at the Hungaroring, securing the lower two podium slots in a race in which Daniel Ricciardo was the fastest man on track after the Safety Car and very much in contention for victory.
Although there were extenuating circumstances – compromised races for both Mercedes, a track configuration that doesn’t punish Red Bull’s power shortfall and a tyre strategy that saw the Red Bulls on the faster tyre on low fuel when most of those around them were on the harder prime tyre – there was still reason for optimism.
Since its Silverstone upgrade, the car has been on a positive upswing in performance, its aerodynamics working much more effectively. The RB11 is finally now somewhere near the competitive level of last year’s car – i.e. not a Mercedes-beater on merit, but in the hunt as the best of the rest and ready to pick up the pieces should Mercedes falter.
In Hungary it was Ferrari which picked up those pieces, but it could just as easily have been Red Bull. So what has changed?
"The aero boys have made some improvements to the front of the car," says Christian Horner. "The regulation change over the winter actually hurt us at the front end of the car and it’s taken us this long to recover."
Two small, apparently innocuous, regulation changes into 2015 had a profound effect on Red Bull’s aerodynamic philosophy.
The first of these was the switch to titanium in the skid blocks from the previous much harder, denser metal. The titanium used around the measuring holes in the planks (the plank determines the car’s regulation minimum clearance from the ground) is around 2.5 times softer than the previous metals and consequently wears out faster.
If the plank is worn – unprotected by the skid blocks – the car becomes illegal. The change of metal meant that Red Bull could no longer run the front of its car quite so close to the ground. For years other teams had been perplexed how Red Bull could run the front of its floor so low that it could be heard from in-car scraping along the road.
The inference was that the gains found in under-body downforce were more than the losses from the frictional resistance this would cause. The way Red Bull had got its underfloor aerodynamics to work made spectacular use of the more pronounced venturi shape of the underbody created by running the front low and the rear high.
For 2015 it was no longer possible to run the front so low, thereby bringing Red Bull back to the levels of the others. It still runs more rake than any other car but the front can no longer scrape along the ground.
Secondly, the regulations concerning the nose shape – to avoid the ugly solutions seen in 2014 – changed the airflow in a way that was particularly disadvantageous to Red Bull’s front wing design, less so to that of Mercedes.
Adrian Newey felt that ever since the 2014 narrower-span front wings were introduced, Red Bull had not done as good a job as Mercedes in getting the airflow linked up between front wing, around the wheels and ahead of the sidepod. Into 2015, the difference was even greater because of the nose change.
Red Bull’s new wing, introduced at Silverstone, was much more Mercedes-like in its contours and both drivers reported a significant improvement in high-speed downforce. For Hungary another feature new to the car – a blown front axle – was introduced. Having the air going through the brake cooling ducts exit through the centre of the wheel is another feature that can be used to better link up the airflow from the front wing to the area ahead of the sidepods.
This part of any current F1 car is super-sensitive to flow – a small change in airflow pattern here can impact dramatically on the car’s total downforce. In Hungary it was found that the blown axle actually worked the flow in such a way that the old wing was more effective than the new – and from P2 onwards they ran the combination of old wing/new axle.
Essentially, the regulation changes took away some of Red Bull’s under-body advantage and it has taken this long to recover by compensating improvements in the over-body airflow. In this way, it has moved towards a more Mercedes-like aerodynamic philosophy.
Ricciardo explained how it changed the car. "It’s the first time in a long while where we haven’t really touched the balance throughout the weekend. The car has more feeling now. I felt like I could dictate the balance a bit more and position the car more where I wanted to. It was behaving well over the bumps – even compared to last year’s car. Everything we’ve brought over the last two races, we’ve made work."
The power demands of Spa and Monza mean that Singapore could be the team’s next opportunity to shine – though as Horner points out: "Well, it could be wet in Spa.2