The Hockenheimring provides a strong blend of long straights and slow/medium speed corners, so we often see different cars topping each of the sector times due to their unique performance characteristics. It is therefore important for the teams to consider reducing drag whilst maintaining high levels of downforce, which is by no means easy.
With FRIC gone for the weekend, a lot of setup work will have been done across the weekend and on the simulator at the factory in order to prepare for life without a more stable car for the drivers. In this tech piece we will not only explore the updates that the team have brought but also how the removal of FRIC has affected them.
Without doubt, McLaren arrived to Germany with one of the most interesting pieces of tech seen so far this year. It was originally intended to arrive for Hungary next week but, as we have seen a lot this year, teams have fast tracked updates forward a bit to prepare them for their intended race with the added benefit of potentially running the parts for the race they bring them to.
Let’s begin with the main change to the wing and that is seen on the trailing edge of the main plane and the leading edge of the upper flap, where we can see a sinuous pattern. These are known as tubercles and their primary function is to reduce drag.
Tubercles encourage airflow to pass into the troughs of the edges, funneling it through across the rest of the wing’s profile. If we consider the tubercles on the top flap, the oncoming airflow disperses from the large high pressure region created at the leading edge of a traditional wing to more dotted regions. This is because pressure is built up more on the peaks of the tubercles and not within the troughs.
The top flap is moveable under DRS conditions and this is where the tubercles work at their best. When DRS is open, the top flap is, say, 10 degrees to the horizontal. This is almost dead in line with the oncoming airflow. The tubercles will be working hard to disperse the high pressure region at the leading edge of the wing, reducing drag by as much as 10% according to some studies. This allows the team to run more rear downforce without the drag penalty.
The trailing edge tubercles remain a bit of a mystery as to how they work, but I’m sure I’ll find out something so keep an eye out on my Twitter page.
Onto the yellow highlighted area, indicating a small tweak to the rear wing endplate. Two sets of staggered fins have appeared, their arcs diverging from eachother. These fins contribute to enhancing airflow from two regions of the rear wing.
Already been seen on the Lotus rear wing, the lower set are all arranged around the lower slats, which divert air from inside of the endplate to the outside, forming the outwash effect at the rear of the car. The upper set are aligned in correspondence to the upwash of airflow on the inside of the endplate. Each fin induces its own small vortex and low pressure region behind to further encourage the aforementioned effects.
Finally, another element was added to the front wing with the outboard edges slightly re-profiled as a result. The now-6 element wing will induce more consistent downforce across a greater range of speeds.
The removal of FRIC has not affected McLaren too badly and this can be put down to the fact that their aero platform runs off a stiff setup. FRIC usually allowed teams to run a very soft setup which is compliant over kerbs and bumps as the system maintained a nice ride height. As McLaren did not do this, the FRIC-less MP4-29 is probably only a tiny bit slower than previously.
Red Bull, Renault and Total
Whilst Red Bull had some changes of their own for this weekend, Renault and Total brought a larger performance chunk to the German GP. Renault’s software updates – which are aimed at extracting more power from the ICE – were worth, according to Remi Taffin, “tenths” of a second in laptime. Total’s new fuel was allegedly worth as much as 12bhp according to some reports, although most of the Renault-powered teams were generally unimpressed by both the fuel and software changes.
Red Bull tested two versions of rear wing (one more orientated around decreasing drag) and also fitted a slightly modified cascade winglet. The inner winglet’s previous miniature endplate has been removed, with the two elements now curled upwards to generate a small set of vortices.
Germany is not really regarded as a “power circuit”, but the lack of Renault punch has certainly cost the Milton Keynes outfit. The car looked great through the last sector where its all corners, but the middle sector was a nightmare. It is clear that Red Bull have not been affected much by the FRIC ban, although they do have other passive ride height control systems.
A slightly re-profiled sidepod airflow conditioning vane, tested at Silverstone, has been used on both cars for qualifying and race. The adjustment features a small lip near the cockpit, along the horizontal segment of the vane, to extract more performance from the airflow trailing from the vortex generator upstream. This air will be fed down the sidepod along the centre of the car towards the Y-lon that surrounds the exhaust exit.
There were no visible modifications made to the Mercedes this weekend but Lewis Hamilton’s brake failure during qualifying sparked an interesting insight into both Mercedes drivers’ brake choice.
Each team chooses their brake supplier. Most teams have either Brembo or Carbone Industrie but McLaren for example use Akebono. Normally a driver likes a certain caliper-disc combination and sticks to it throughout the season. At Mercedes however the drivers can switch between both Brembo and Carbone Industrie during the weekend and decide which is best for them before qualifying. You can’t change specification after qualifying as this would break parc ferme rules.
At McLaren, Hamilton preferred Carbone Industrie brakes as they gave him the bite that he needed to brake late plus a bit more feel as the power varied compared to Akebono. When he moved to Mercedes the team were using Brembo brakes, a feature that did not suit Hamilton’s braking style. Brembo brakes tend to provide more peak power but offer far less modulation. For 2014 Carbone Industrie were called in to address Lewis’s problems.
Hockenheim has a couple of big braking zones but nothing too testing regarding modulation. This is why Hamilton opted for Brembo brakes ahead of qualifying. Nico Rosberg, interestingly, used Carbone Industrie.
The two manufacturer’s brake discs heat up in different ways, with the Brembo discs heating up more quickly which helps provide better stopping power. Track temperatures were well into the 50 degree mark so brake temperatures will have also been high, but Hamilton’s right front brake disc failure that sent him out of qualifying was not the first time such an issue has occurred on a Brembo disc this year.
Mercedes, Sauber, Marussia, Caterham and others have all suffered a similar problem and it has recently been pinpointed down to Brembo’s new silicon supplier – silicon is used to coat the brakes to prevent the carbon from overheating. The new coating is more prone to cracking and thus exposes the carbon to higher temperatures, risking a failure.
Images courtesy of Octane Photographic