Q. The shape of the VJM02 is radically different from that of its predecessor. Can you talk us through the new aero rules and Force India's interpretation of them?
If we talk through the car from the nose, the front wing looks very different. The wing must be 1800mm wide by regulation so it stretches to the widest point on the front tyres, making it look very flat and, obviously, extremely wide in comparison to the 2008 wing. With an FIA-prescribed central section, and two working sections that are towards the outside of the wing, it also works in a very different way from last year.
In 2008 this wing was narrower and the whole section was working very hard and pushing the air flow inside the tyres and under the car. Now, the air hits the front wing and its up-wash is directly affected by the tyre so it must flow in several different directions , which creates a much more complicated problem, particularly as the rest of the bodywork is also subject to very strict regulations.
The bodywork is now much more like a 'jelly mould', that is there are no elements hanging off the bodywork, so no bargeboards, chimneys, louvre panels or any 'add on' devices that manipulate the flow of air over the car. All the bodywork must comply to a set of 75mm radii so the VJM02 has a much more curved, clean profile compared to 2008.
Of course the lack of these outlet devices and the changes on the rear has had a fundamental impact on the cooling of the car. Now there are only two cooling exits, and the air has to exit via rear of the bodywork just ahead of the rear wheel centreline.
Moving to the rear of the car, the diffuser is lower, wider and further back on the car. The second more obvious difference from 2008 is that the rear wing is a lot higher and narrower. The maximum width of the wing is 25 percent smaller with only two wing elements. It's now a lot more aligned with the rear diffuser so more difficult to get them to interact compared to 2008.
Q. In another new regulation, the front wing is also moveable.
JK: Yes, the front wing is the only legal driver-adjustable aero device on the car. It is activated by a button on the steering wheel. It can be moved up or down by three degrees and is there primarily to help with overtaking. In previous seasons we have had situations where cars could follow one another but couldn't overtake as the front end lost downforce and grip when the cars got too close. Now, the driver can adjust the wing twice per lap so if he is following a car he can get close enough to pass on the exit of the corner.
Another benefit is that if the car develops a handling issue, such as tyre degradation for instance, the driver can hit the button and try to address the problem.
Q. Has any of the 2008 testing helped?
JK: In the last part of 2008 we set the car to 2009 drag and downforce levels to get an idea of how the car would behave with the new regulations, but very often we had a cold track and it hasn't been very representative! We know we have compromised on testing with the late debut of the car, but we have a very defined winter testing programme from now on and in general the positives on the McLaren/Mercedes deal have far outweighed the negatives.
Q. Has the relationship with McLaren and Mercedes had an impact on the aero design of the car?
JK: To a certain extent, yes, as we have had to adapt the bodywork to fit a new, slightly different shaped engine, gearbox and KERS. We haven't had to start from scratch but we have had to repackage and redefine certain areas, such as the side pods, cooling and the rear of the car. We spent a long time trying to get the bodywork right and the guys in the wind tunnel design office have done an excellent job in interpreting the regulations. It is still very early days and I think we will still find new directions as development progresses.
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