F1 teams' mid-season tech priorities

The Formula 1 development race has entered a strange phase as we approach the summer break, with teams trying to balance continuing development on their current cars against working on the big rule changes coming for 2017.

A grand prix and post-race test at aero-dependent Silverstone offered plenty of hints at various teams' approaches, so here's a round-up of who is working on what at a time when everyone's resources are being pushed to the limits.

MERCEDES
Aero and ERS cooling in focus

Mercedes' latest specification of rear wing follows a direction used by Toro Rosso since the start of the year, featuring drag-reducing louvres at the front of the endplate.

Now Mercedes has a specification with the open louvres and four strakes fitted to the outside of the panel. Having the louvres open is a small gain to prevent airflow separating on the front part of the endplate.

Mercedes also continues to evolve its complex bargeboards. At Silverstone the number of vanes in this set-up was reduced, but they were more detailed than before to slot between the vanes on the leading edge of the floor, improving the effect on the underfloor of the car.

These changes could be the reason for alterations to the diffuser, with both the centre flap under the rear crash structure and the outer edges of the diffuser reshaped.

A change in the bulge on the rear of the engine cover shows that, for the second year running, Mercedes has altered its ERS cooling mid-season. Underneath the bulge is a water cooler for the ERS that sits above the gearbox. This cooler has been enlarged, resulting in the reprofiled bodywork shape.

Better ERS cooling will improve reliability and the ability to recover energy before the cycling of electricity through the MGUs and ECU creates too much heat and forces the driver to switch to a lesser harvesting mode.

The general shape of the sidepod appears to have also been changed with a slimmer coke bottle area created by the flanks sloping downwards more.

FERRARI
Learning from 2017 developments already?

Ferrari's recent updates have not been as comprehensive as Mercedes', but it has added revised parts to the front wing and some new fins under the chassis.

It's the new fins that are the curiosity, with just a tiny vane added below the raised section of chassis above the splitter.

Their function is the same as the turning vanes fitted ahead of them under the front suspension, which is to shape the airflow downstream, keeping the front tyre wake away from the centre bodywork of the car.

What makes this development interesting is that this is an area where there is greater freedom with the 2017 rules. It's possible Ferrari has found developments that were planned for next year useful for its current car.

The outer space of the wing is now slightly more aggressive, though this is almost undetectable without direct comparison from the old specification front wing to the new version.

The arched section towards the outer tip of the wing has been reshaped, now being taller and more rounded. While a bigger arch has been formed, this shape is still relatively small and rounded compared to Mercedes' larger square shaped arch in the same area.

The purpose of the arch is create a strong vortex from under the wing to direct airflow out around the front tyre. Alongside the reshaped wing profile, the endplate area has also been changed, with the vertical vane having a larger undercut and the strake fitted to the outside face of the vane also being subtly changed.

RED BULL
Measuring the halo's aero impact

Despite Red Bull's improving pace, there is little development evident on the RB12. Testing after the British GP allowed the team to run the halo cockpit structure for the first time.

For this run Red Bull fitted the car with aero sensors, the most interesting being the one under the airbox inlet. This area under the rollhoop is currently used by Red Bull as a cooling inlet for the ERS, so the inlet was filled with aero probes to map the disturbance in airflow the halo creates.

If the halo gets final approval for 2017, one of the design issues for the teams will be this obstruction to the rollhoop inlets, which will affect engine performance and cooling.

WILLIAMS
Rear aero under the microscope (and laser)

During testing Williams fitted the rear wing endplate with three pieces of test equipment that were in fact looking at the rear tyre. One of the parts was a laser shining a green line horizontally across the tyre's sidewall, the other two units were cameras looking at how the line's shape changes as the tyre deforms around the lap.

Tyre shape is a critical factor in aerodynamics. The amount the tyre moves and the shape it deforms into affects the gap between the floor and tyre and the rear brake ducts and wing endplate.

At the end of testing Williams again ran the big rear wing seen in Barcelona testing earlier this year. It is not legal for 2016, nor is it an example of a '17 rear wing. Its purpose is simply to add more downforce to allow the team to replace the sort of aero loads the larger diffuser and rear wing for next year will provide.

FORCE INDIA
Ironing out the downsides of its successful upgrade

With its increased pace since the car was updated, Force India has started to struggle with tyre management. To rectify the tyre issues the team reverted to an older format of rear suspension, although the unpredictable weather conditions in Britain meant it couldn't fully prove the problem is now resolved.

It has also revised its front wing - the change is just to a section of the wing, not a wholly new part. At this stage of the season and with the current regulations, it is more effective for the teams to make small alterations to the wing and not invest in the development and manufacturing to build a completely new version.

Now, the footplate that extends outwards from the wing tip is a little wider and droops down slightly.

TORO ROSSO
Cooling ideas in the works

At the Silverstone test, the car was fitted with a new cooling set-up. The top bodywork was new, with two inlets either side of the rollhoop feeding back to a cooler above the gearbox.

This may be a development for the upcoming races, but is most likely to be a set-up specific for October's Mexican GP, which due to the thin air at high altitude requires extra cooling.

McLAREN
Better packaging for Honda

Since Honda's return to F1 in 2015 the engine packaging has been compromised for McLaren's 'size zero' approach. This affected the inlet system, which was trying to both be raised up to fit the turbo underneath and also low to allow sleek bodywork lines. To accommodate these conflicting requirements, the inlets inside the plenum had to turn through 90-degrees, which hurts engine performance.

Now the inlet plenum is much taller, which allows more space for the inlets that are now pointing straight up, which will improve flow into the engine. Furthermore, the reshaped plenum should allow for a larger turbo and MGU-K to be introduced later in the season, further boosting power and reliability.

On the chassis side McLaren is still on a steep development curve, and it continues to introduce regular aerodynamic updates. Recently these have included a revised front wing, a new T-tray splitter, different front brake ducts, new rear tyre floor slots and a revised diffuser.

RENAULT
Data gathering for 2017 changes

With development muted for 2016, the recent Silverstone test was a chance to rig the car up with sensors and gather data in preparation for '17. One particular test involved the wheels being fitted with sensor units on each axle, with a support/cable then passing around the tyre back to the chassis.

These are wheel force sensors, which measure the actual load at the wheel rather than by the movement of the springs and dampers inside the car.

Data from these sensors can be used in several ways, such as to detect any lack of stiffness in the suspension, as any difference between wheel forces and suspension movement can be caused by flex in the suspension.

Data from this type of test will also help the team produce tyre data models to be used in simulations, allowing Renault to predict the on-track behaviour of the car more accurately.

SAUBER
Playing catch-up in the aero race

Sauber had not run major updates previously this year, so the arrival of a new rear wing at Silverstone is welcome news.

To date, Sauber has run with an old rear wing supported by a hybrid mounting pylon. This mounting pylon joins to the single mounting on the Ferrari gearbox and then splits to meet the double mountings on the old rear wing. Now the wing is a single pillar from top to bottom, saving crucial weight at the back of the car.

On the new rear wing the endplates follow both Toro Rosso and McLaren practices. The upper louvres are open fronted as with the Toro Rosso and Mercedes, but these slots are longer and merge into the rear wing flap itself for a stronger drag reduction function.

Below this there are another set of inlets moulded into the wing, as with the McLaren, these also feed air under the wing to reduce the drag created by the vortices formed at the wing tip.

This new rear wing assembly is likely to have been planned as part of the car since its launch, but delayed due to the financial restrictions Sauber has been forced to operate under, a situation that will hopefully change now that its takeover deal is complete.

More aero updates are expected to appear this weekend in Hungary and Sauber has started carrying out 2017 preparation during free practice sessions.

As part of 2017 work, the current car has been fitted with a large 3D-printed top cover over the top of the chassis.

It is believed the part was the intended shape for the 2017 chassis, the shape being at the upper limit for the chassis height and featuring a distinct slope towards the front. This is the shape most of the current teams have reached with their cars, so Sauber is yet to fully catch up on meeting the limits of the rules in this area.