Tech Talk: Detailed analysis of Force India's B-spec car
Force India's B specification was finally unveiled at the British Grand Prix and marked the culmination of the teams move from their own wind tunnel facilities to the Toyota tunnel in Cologne. The team had already pulled the covers off a few of the updates at the in-season test in Austria, using the track time to correlate data on those parts.
The most obvious of the updates is the new nose which features two 'nostrils' in the upper surface, however, the car features a mouth watering array of new parts that should help to boost their performance over the coming races.
The new front-wing bears a significant resemblance to the philosophy employed by Red Bull up until most recently, not a bad way to go considering their pedigree over the last few seasons. Outwardly it may look very similar to the old specification but every surface has been reworked.
A new endplate curves over to meet with the new mainplane and footplate arcs (marked in purple above), the endplate itself is completely different in its approach with the flaps, which now form part of the footplate, allowed airflow by virtue of the endplates slot. Meanwhile the canard mounted on the outside of the endplate (marked in dark blue above) has been moved, flattened and its orientation changed, leading to a change in the pressure gradient it creates.
The flaps which as previously mentioned now merge with the footplate have been completely redesigned and should allow more flexibility in terms of setup. A four full flap configuration has been traded-in for a five full flap configuration with slotted upper flap.
The two tier cascade has been swapped out for a three tier design (marked in red), whilst the vertical fin placed in the middle of the cascade (marked in light blue) has been replaced by two fins and a thermal imaging camera, in order to monitor temperatures on the tyres surface.
Replacing the 'r' cascade (marked in green above) are two small horizontal winglets, which also act as the cascades structural support by virtue of the metal stay.
An inboard canard can now also be found hanging from the endplate (marked in orange above).
The front-wing (and nose) of the car represents the first impact on the airflow, meaning it sets up all the flow structures for the rest of the car, whilst also having to provide aerodynamic balance from the downforce it generates. The latter is a given with F1 teams able to generate more forward downforce than is often needed, which gives them license to compartmentalise the wing to achieve other effects.
Primary to these is the need to create the right Y250 vortex where the flaps meet with the neutral central section of the mainplane, whilst also controlling the wake generated by the front tyre. This has been of particular significance since the rule changes in 2014 as the teams look to improve rear downforce whilst reducing drag. The changes that Force India have made with this update are largely aimed at dealing with tyre wake and its influence on the car downstream.
The new nose is an interesting interpretation of the regulations, one I'm sure many of the teams looked at when designing their own. The 'nostrils' allow airflow to pass from the upper surface of the nose back under the nose whilst circumnavigating the single cross section regulation. This is because when you look at the holes in the upper surface from above you cannot see through to the floor, instead the holes on the underside of the nose (highlighted in green below) are offset, allowing airflow to merge under the central portion of the nose.
For all intents and purposes this is meant to mimic the nose tip not being there, as the nostrils increase how much flow is committed under the nose, ideally returning the team to a similar level of performance seen before the low nose tip rules were introduced. Of course it can't go that far but it's a less structurally demanding way of passing the crash tests whilst mimicking if not improving on the short nose solutions run by other teams.
The sidepods and engine cover must be designed with great care, as aerodynamically both the internal and external airflow they preside over can have a large impact on the car in general. The update saw changes to both, starting at the sidepod inlets where the team have reshaped the inlets and, like others, shrink wrapped the sidepods shoulder bodywork around the upper 'spec' crash structures, creating a blister on the sidepods shoulder (marked in yellow).
The shape of the sidepod outlets at the rear of the car now encourage more airflow into the coke bottle region, whilst a change in exhaust philosophy has also led to the bodywork around it being tightened, shrinking the entire cooling outlets profile.
The exhaust now lies directly atop the crash structure/gearbox casing, with the last portion of the exhaust tilted upward (marked in red) to interact with the airflow structures developed by the diffuser and rear wing.
Meanwhile, the oil cooler that used to sit astride the exhaust has been moved into one of the sidepods. This follows the same design continuity we saw from the team at Silverstone in 2014 as they looked to improve the VJM07 mid-season. This allows the engine cover to be shrunk down further and an enlarged shark fin (marked in green) used simply to meet the size regulations, whilst the rear wing support pylon is increased in length in order to meet the more svelte engine cover. These changes have all been made in order to maximise the cooling potential, whilst improving aerodynamic performance.
The changes made to the VJM08 won't be enough to leap-frog the team to the front of the grid but it'll be handy as they continue to bring updates and challenge the established order at the front of the midfield.