Renault's guide to Monza set-up 01 Sep 2005
Fernando Alonsos race engineers, Rod Nelson (chassis) and Remi Taffin (engine) explain the technical requirements for achieving a fast lap around Monza, setting for Sunday's Italian Grand Prix.
Rod Nelson: When it comes to setting the car up for Monza, it is all about striking the right balance between absolute chassis and engine performance, and driveability. A very stiff set-up may look good on paper, and better horsepower figures might seem desirable - but if they come at the price of poor driveability or peaky engine performance, they can actually make the car slower. Instead, we need to find the balance between pure performance and useable performance.
Unlike many circuits we visit, where downforce is one of our major considerations, drag is studied just as closely at Monza. Of course, the aero department produces wings specifically for this track as it is now so unique in the calendar, and minimising drag is an even greater priority than usual for these Monza packages.
The circuit is quite bumpy into Turns 4 and 11 (the Roggia chicane and Parabolica), probably because of the circuit's age. However, with the low downforce levels, this becomes more of an issue than usual. In addition, the drivers use the high kerbs aggressively through the first and second chicanes, meaning we run the car relatively soft, and with a forward mechanical bias (stiffer at the front) in order to get the best mechanical grip and good braking stability.
In terms of ride heights, there is a performance advantage in running low front ride heights in the slow speed corners. We try to achieve this without touching too much on the straights, and we do so by running bump rubbers on which the car sits' at high aero loadings. It then rises up from these in the slower corners, and the suspension works more conventionally in order to get optimum grip.
Of course, Monza is a power circuit - but also one where the cars spend 13 percent of the lap braking. This means that the brakes undergo severe stress - the high speeds of the start finish straight followed by the low speed Turn 1 impose a deceleration of some 300 kph, the making this the most severe corner of the year. Cooling the brakes efficiently is an important area to which the aerodynamicists pay attention ahead of the race.
Remi Taffin: Monza is the most severe test a Formula One engine encounters. The circuit offers no respite, with 71 percent of the lap spent at full throttle and no sequences of slow corners at low throttle openings. With an average lap speed of 260 kph - compared to a season average of 220 kph - this is comfortably the most severe duty cycle of the season.
The high proportion of the lap spent at full throttle means that engine power has the biggest influence of any circuit of the season. This year, with the RS25, we have not only a driveable V10 but also an engine that is competitive in terms of its power output. However, pure power is not the only important characteristic: the engine needs to be driveable from low speeds on the exit of the chicanes at Retifilo and Roggia, and to provide smooth power delivery to allow the driver to take the optimum line through these slower sections.
In terms of reliability, the severe duty cycle is clearly a demanding challenge. In addition, the chicanes pose an additional worry as the car's passage over the kerbs can lead to the rear wheels losing contact with the ground - and potentially to either hitting the rev limiter, or to damaging the transmission when the spinning rear wheels land back on the track surface. The violent forces the car undergoes can also potentially have consequences for the reliability of accessory components such as oil and water pumps.
In 2005 more than ever, the pre-Grand Prix Monza test will prove useful for the engine team. This test allows us to conduct some of our usual Friday tasks - such as selecting gear ratios and determining cooling levels - during the test, and hence allows us to economise our mileage. With Monza forming half of the most demanding pair of races of the season, with Spa, laps will be at a premium - and each team running fresh engines in Monza will be monitoring closely how they exploit the two-race performance potential of their engine. Any small gains of this nature could potentially prove valuable come the race in Spa next weekend.