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"The Monaco Grand Prix is not just famous because of its history
and its picturesque setting, but also because of the unique technical
challenge it presents the drivers and engineers. Until a few years ago, part of a driver’s armoury for Monaco, was heavy padding to his gearchanging hand, to prevent the gearlever causing blisters. Today, he simply flips the paddles on the back of the steering wheel. But while the driver might have an easier time, the gearbox itself still takes a tremendous amount of punishment at this track. The gearbox is the component with one of the longest lead times on the car, in terms of its design, construction and development. It is not a true performance item, but rather a reliability item, with performance as a secondary function. “The design of the box is linked pretty closely with the car’s aerodynamics,” says Scuderia Ferrari Marlboro gearbox specialist, Diego Ioverno. “The biggest challenge we face is to be able to come up with an effective gearbox in the layout space we are allowed.” The new rules concerning aerodynamics for 2005 have led to some major structural changes. This comes particularly from the new floor design which places it much closer to the gearbox. “In dealing with the changed regulations, our aim was to have at least the same performance from the overall car package and one of the areas that had to make some sacrifices was the gearbox,” continues Ioverno. “It is part of the job, we have to live with it and do our best, but it is fair to say that we work in a compromised environment because the gearbox can be viewed as a power wasting component located between the engine and the wheels!” In simple terms the bigger the gearbox, the more reliable it will be, but size and weight are the key to performance and engineers are always trying to lose weight in parts of the car to have the ballast as low as possible to lower the centre of gravity. It is no secret that the F2005 gearbox has suffered some reliability problems early in its life and Ioverno reveals that these stemmed from a new concept in terms of the gearbox casing. “The main change for this year concerns the materials we use to manufacture the casing. Two years ago, we had a titanium casing. Then last year we had a titanium-carbon casing and this year we have increased the carbon content and carbon is a tricky material to work with. As soon as you use a new technology you have many lessons to learn and problems to solve. This is the challenge we face, combined with the fact that development time is very short.” It might seem strange that the casing, which the casual observer might think is just a container for the gears themselves, can cause a problem. “But the gears and other parts move in terms of the way the box lets them because the casing supports the internal components,” explains Ioverno. “The difficulty of managing this situation in engineering terms is that the metal internals and the carbon casing operate in different thermal conditions. So we have higher stress inside the gearbox.” In terms of gear shifts alone, Monaco provides the severest test of the year. “Just for the race, the driver will make 3600 gear changes which is about 20% more than the lowest gear change circuit which is Monza,” says Ioverno. But the nature of the circuit adds further complications. “Monaco is a very strange, with all the kerbs the manhole covers, the drains. The driver never shifts in the same place in the same way, so setting up the gearbox for Monaco is a real challenge. As the car moves over a drain or a kerb, the entire transmission starts oscillating and if you try and shift gear at that point, it is very difficult to operate the shift. F1 gearboxes do not have syncromesh like a road car, so we synchronise the shift by controlling engine revs and coordinating it with the actuator that controls gear shift movement. So you have to be in phase with what you want to do. If everything is oscillating you are out of shape and risk big shocks or a bad shift or both.” So it is a misconception that the arrival of sophisticated gearchange
technology has meant that drivers can no longer miss a gear shift. “You
have to consider that a shift lasts a few milliseconds,” says Ioverno.
“In such a small range of time, a lot of things happen. So if you
are doing a shift just as the engine takes a spike because of a kerb,
the gearshift goes out of shape. You may also be unable to shift. Everything
is on the limit and our actuators are not built to shift gears on a truck!
If the torque you have to deal with is higher than a certain level then
you can no longer achieve the gear shift. The upshift only upsets the car in terms of power loss, but the downshift
is very important in terms of the stability of the car. Because in a road
car, if you go from fifth to first in one second, imagine what would happen
to the rear wheels. In an F1 car a driver can ask to go from seventh to
first in less than three seconds. Add these complex requirements to the
challenge of the Monaco track surface and it is clear that the unglamorous
gearbox plays a vital role in the glamorous Principality. " Click here to return to the Ferrari Happenings page.
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