Interview with Willy Rampf, Technical Director of the BMW Sauber F1 Team
“If we used our Monaco car in Monza we’d be over 50 km/h slower.”
Munich/Hinwil, 4th September 2007. The Italian Grand Prix in Monza represents
a unique challenge for drivers and engineers alike. Willy Rampf, Technical
Director of the BMW Sauber F1 Team, explains how he and his colleagues go
about preparing for this race.
What makes Monza such a special track?
Willy Rampf, Technical Director: “Monza is a classic high-speed circuit with
extremely long straights, comparable only really with the old GP track at
Hockenheim. At four points during a lap, the drivers hit speeds well in excess of
300 km/h and 76 percent of the lap is spent at full throttle. This is significantly
more than at any other Formula One track, and that is why we run lower
downforce at Monza than anywhere else over the course of the season.”
What does that mean for the car’s aerodynamics?
Rampf: “We have developed a ‘low-downforce package’ of special
aerodynamic parts for this race. At Monza we run less rear wing than at any
other circuit. And in order to achieve the right aero balance we have also
redeveloped and adapted the front wing. In addition, we examine the
aerodynamic efficiency of all the car’s detachable parts for Monza. Only the
most efficient of these are left on the car. Indeed, we remove several elements,
as doing so enhances performance. We are taking the opposite approach to
the way we prepare for Monaco, for example, where we generally add every
part to the car that will generate extra downforce.”
Staying with Monaco for a moment – how much less downforce do you
run in Monza compared to the street circuit in the principality?
Rampf: “In Monaco the cars only reach 290 km/h at one point on the circuit,
whereas in Monza they comfortably exceed 300 km/h in four places. For this
reason the engineers set out to minimise drag, and that means giving away
around a third of the car’s downforce. In Monaco downforce is everything, while
in Monza the drag coefficient plays a major role. Having said that, you can’t
afford to neglect downforce altogether. After all, the drivers also need to be
able to brake late and accelerate quickly through the corners.”
How do the top speeds of the two tracks compare with one another?
Rampf: “The low-downforce package allows the F1.07 to hit a maximum speed
of around 350 km/h at the end of the start/finish straight in Monza. If we were to
run the car in Monaco specification the drivers would not reach 300 km/h, as
the engine output would no longer be sufficient to overcome the mushrooming
air resistance.”
How did the contributions of the wind tunnel and the supercomputer
with Intel processors compare in the development of the aero parts?
Rampf: “The two are closely intertwined. The development of these parts
involves interaction between the knowledge gained in the wind tunnel and the
results of computer-aided flow simulation, otherwise known as Computational
Fluid Dynamics (CFD). CFD and the wind tunnel are mutually beneficial. CFD
has advantages when it comes to the development of wing concepts, for
example. The wind tunnel, on the other hand, is unsurpassed in perfecting the
car’s overall aerodynamic set-up.”
How do you adapt the car mechanically for the Monza circuit?
Rampf: “In addition to achieving the highest possible top speed, it is also critical
for the drivers to be able to drive aggressively over the kerbstones. The track
features three chicanes leading into full-throttle sections. It is important to nail a fast exit from these corners, and to do that you need sufficient traction. The mechanical set-up of the car represents a tricky compromise. It has to be soft
enough to ride the kerbs efficiently and provide good traction, but go too soft
and you’ll be short on stability through the high-speed corners.”
What kind of stress do these track characteristics place on the
brakes?
Rampf: “When it comes to the brakes, Monza literally blows hot and cold. On
the one hand the long straights give them a lot of time to recover, but braking
from seriously high speeds generates extreme loads every time. The end of the
start/finish straight is the hardest braking zone of the entire season, the drivers
slowing from 350 km/h to 70 km/h within the space of three seconds and
enduring maximum deceleration of 5 g. The brake discs, meanwhile, briefly
reach temperatures of well over 1,000 degrees Celsius. What makes braking
under these conditions particularly tricky is that on the long straights the
carbon discs cool down more than the drivers would like – to under 400
degrees. When they then stamp down with some 100 kilograms of pressure on
the brake pedal, for a split second or two the brakes do not bite with full power.
That is something the drivers have to be prepared for.”
And what about the loads on the engine?
Rampf: “Monza makes the engines work harder than at any other GP. This
circuit boasts the highest full-throttle percentage – 76 percent – of any venue
on the calendar. This means that the engines are running for exceptionally long
periods at high revs. However, we don’t expect any problems since the
homologated engines are designed to withstand loads of this order.”