Spa and Monza are two circuits that come at a convenient time on the F1 calendar as their place in the season – just two weeks apart from eachother – allows the teams to finalise their low downforce packages over the summer break.
Spa in particular has always represented a dilemma for the teams: do you go high downforce for the middle sector and compromise top speed, or opt for a low drag setup for S1 and S3 at a risk of losing out if it rains? It is for this reason that we see a mix-and-match of both low drag rear wings and high downforce front wings, although this year the teams had more unique combinations than usual thanks to the high top speeds these cars reach even with a high downforce package.
Ferrari in particular went through a lot of various options to suit their drivers’ needs, but due to the downpour before qualifying both Fernando Alonso and Kimi Raikkonen ended up with a higher downforce setup. This included a slightly skinnier rear wing than their normal specification and their standard front wing with cut down upper flaps.
Whilst there was a low downforce rear wing available – featuring a slim main plane and only three louvres cut into the endplate – there were also two other front wing options, one of which is the above illustration.
The wing above is the lowest downforce wing. The upper flaps have been cut down inboard to reduce the surface area presented in this region whilst retaining a strong formation of the Y250 vortex in a bid to manage front tyre wake at increased speeds. Gone are the main cascade winglets and in their place are two vanes (highlighted). The endplates of the deleted cascades features a set of vortex-generating flick-ups – the two vanes are installed to emulate the flick-up’s characteristics, without the added drag of the winglet.
The final front wing was the low downforce wing plus the cascade winglets, creating a middle ground between high and low downforce variants.
There were also mechanical changes made to the F14 T, most notably the new exhaust header insulation material, although unlike Marussia – who have been used as a guinea pig in this area of technology – Ferrari have not opted to use a surrounding carbon fibre case. Insulating the exhaust will, obviously, retain more heat within the pipework, which increases boost pressure.
At a circuit like Spa where driveability comes after overall power output, the insulation makes sense: some are claiming a 10bhp benefit from running such a setup. The downfall of the insulation is that the turbo spools at a much faster rate which affects how the driver can put the power down. The MGU-H can do a good job at harvesting energy during this stage and slowing the turbine down, but it can still be an issue.
There was a lot of talk in the build up to the Belgian GP that Caterham had a substantial upgrade package ready after additional funds were conjured up by the new owners. Whilst their Spa update was visually different, there wasn’t much new on the car although I expect further developments to come through over the next few races.
The new nose was the most obvious change to the CT05. The main crash structure remains unchanged but the non-structural vanity panel on top has been thinned to reduce weight and streamlined to produce the same effect as the previous panel but in a much more efficient manner. Most notably the top surface has been completely re-profiled, setting up airflow nicely over the top of the car compared to the previous version. The underside of the panel continues to act as a channel for air to pass under the chassis, assisting rear downforce and making use of the attached turning vane immediately behind.
Further back, the car’s Coke-bottle section of the sidepods was shrink-wrapped inwards and nearly hugs the gearbox case. Caterham have also adopted the cooling solution used by many this year, extending the sidepods through the suspension elements to create one large outlet across the back of the car.
Aside from a cut down front wing and their low downforce rear wing already seen this season, Sauber didn’t have much new aerodynamically.
However we did see an interesting change to the brake duct drums/cake tins. Instead of leaving them in raw carbon fibre, the drums were covered in what appeared to be Zircotec, an insulating coating that we have seen used on exhausts before – particularly during the blown diffuser era. Spa has a lot of long straights followed by heavy braking zones, so retaining heat within the brakes is crucial to a good lap time. It will be interesting to see if other teams want to copy this idea themselves.
Despite removing the upper mushroom fairing on the rear suspension, the MP4-29 remains quite a draggy car which isn’t really producing enough downforce. It’s a tough situation to be in and difficult to repair, but a number of changes were made to the car this weekend to attempt to alleviate the situation.
A new diffuser was installed which featured the Mercedes U-bend in the central channel. The U-bend is a great way of managing the rules surrounding the stater motor hole, which state that the hole must either be covered by a flap or not visible from beneath the car. As the U-bend is a vertical slot, it cannot be seen from beneath the car but still allows the team to use it as an aerodynamic device alongside the diffuser.
The slot itself is used to direct airflow passing around the sidepods out of the back of the car as efficiently as possible. However it’s the U-shaped profile created by the slot that helps aerodynamic performance: it creates two separate channels at the centre of the diffuser for air to pass through, managing the expansion of the diffuser to increase rear stability. Whilst overall volume is lost, expansion at the outer regions of the diffuser is increased as a result of the more efficient area at the middle of the car.
Another new rear wing was brought, retaining the top flap’s leading edge tubercles (explained here) from the German GP wing but deleting the trailing edge ones on the main plane.
The main plane curves upwards at the outer regions of the wing, reducing the angle of attack and thus relieving the wing tip vortices shed at high speed. To further manage these vortices the endplates include three louvres, reducing the pressure delta between the upper and lower surfaces of the wing.
Removed to decrease drag are the array of fins/canards filed along the endplates and also the winglet attached to the Y-lon central wing support.
Like Ferrari, Red Bull also had various options for their drivers to try out. Both drivers eventually went for an incredibly slim rear wing, with both RB10s retaining their normal aerodynamic package over the rest of the car.
The rear wing had a very skinny main plane, such that there was no need to include vortex-reducing louvres in the endplates. Such was their reduction in drag that Daniel Ricciardo was the fastest through the official speed trap after a dry FP2 session. A rarity to say the least!
Traditionally Red Bull’s philosophy has been to pack the car with downforce and rely on making up time through the corners, a strategy that has generally worked well for them over the past 5 years. However with the Renault power unit being so far down on power compared to the opposition, a change of approach was probably a very good decision and the fact that Daniel Ricciardo had the pace to win in the end proved that it was indeed the right call to make.
The fastest car in F1 continues to get faster, qualifying 2 seconds faster than the next best car, the biggest margin this year (albeit in wet conditions). Changes were made across the W05 to reduce drag and weight.
Starting with the nose, the upper portion is now more concave, allowing the team to further sculpt the bottom of the nose to encourage airflow into the path of a brand new set of under-chassis turning vanes. These vanes have four elements – up from three – and make use of the additional space created further forward. The nose itself has a thinner vanity panel to reduce weight, hence why it needed crash testing before arriving onto the car.
Mercedes have saved as much as 8kg of weight so far this season by re-constructing various pieces of bodywork, allowing the engineers to place more weight at the middle of the car and lower down to meet the minimum weight limit.
A vertical vane was integrated into the upper area of the front brake ducts, setting up a nice vortex heading along the side of the car to further manage front tyre wake in front of the sidepod.
At the back of the car there were numerous alterations. A new rear wing was used for the entire weekend, with a much curvier top flap that drooped down at the outboard edges to reduce drag. The overall depth of the wing wasn’t too dissimilar to that of their normal wing although the top flap’s Gurney flap was later removed to increase straightline speed.
Finally, as seen in testing last month, a low drag Monkey Seat winglet was fitted. Featuring just a single element, it has a far more basic design than their normal specification winglet but its function remains the same. It still pulls the exhaust plume up towards the underside of the rear wing, but with the wing now at a lower angle of attack the winglet below does not need to be as aggressive in design.