Australian GP: Renault engineering preview

Renault's Rod Nelson and Rémi Taffin discuss chassis and engine set-up for the Australian Grand Prix

Chassis set-up with Rod Nelson, Race Engineer, Car 5

"The layout at Melbourne is what we characterise as 'point and squirt': a lot of slow corners linked by relatively long straights. This means that strong engine performance and good traction out of the slow corners, are key factors in getting a competitive lap time."

"In terms of car set-up, we run medium-high downforce levels and try to spring the cars quite stiffly in order to get a responsive change of direction through the chicanes. However, as Melbourne is a temporary circuit, this means the braking areas are often quite bumpy, and this is a limiting factor: too stiff a set-up will see the driver locking up under braking, costing him lap time as well as harming tyre performance over a race distance -- a constant preoccupation under the 2005 regulations. In general, we give the car quite a neutral set-up for the race, although Fernando likes a little understeer in qualifying at this circuit to give him confidence to attack the timed lap."

"Braking is a key factor at Melbourne, with the cars stopping from near or over 300 kph on six separate occasions. Although the individual braking events are not the biggest of the season, the fact they are regularly spaced around the lap means that brake cooling, and oxidisation of the brake discs, is a constant preoccupation. We monitor brake wear very carefully, and extrapolate results from tests on Friday and Saturday morning in order to make our cooling calculations for the race itself."

"When setting the car up, we have to take account of the manner in which track conditions evolve during the weekend on the temporary surface. The tyre wear is usually quite high on the first day, especially on the front tyres, because understeer levels are higher than normal on a "green" or dirty circuit. The wear levels reduce as rubber is put down on the racing line, and tyre wear is normally more balanced front to rear in race conditions."

"For the new season, the way we work in practice will be slightly different compared to last year. In 2004, we made three stops in Australia, meaning the average maximum tyre life in the race stints was 16 laps -- whereas this year, the tyres must last for more than 60 laps, or almost four times as long. This means we will spend a large part of Friday comparing tyre performance on short and long runs, and making the car as easy as possible in its usage of the race tyres: any defect in tyre choice, or set-up, will not be masked by repeatedly fitting new tyres in 2005, and the cost to performance will be greater than it was least year. Indeed, this revised working method is likely to be reproduced through the season as we strive to find the most race-able set-up at each circuit we visit."

Engine set-up with Rémi Taffin, Engine engineer, Car 5

"Melbourne is a tough circuit for engines: its succession of straights broken up by slow corners mean good torque is more important than peak power in order to accelerate out of the slow and medium-speed corners."

"The percentage of the lap spent at full throttle (64%), as well as the average engine speed over the lap, are high; combined with relatively cool temperatures (around 22°C) and high atmospheric pressures (around 1010 millibars), which mean the engine develops more power, this provides the moving parts of the engine with a tough test. Parts such as the pistons are under severe strain, and we look for the best possible cooling compromise to ease the stress on these components."

"During the race weekend, we focus on establishing cooling levels, but also on the detailed electronic work that is specific to each circuit: traction control settings, engine mapping to control pick-up and driveability, fuel consumption and gear ratios. In general, Fernando wants engine response to be as progressive as possible: his driving style sees him use the throttle gently in the first half of its travel, before applying full throttle very quickly afterwards and relying on the traction control."

"Our engine usage strategy for the weekend will also change in 2005. We will need to manage the engine's 'potential' across two weekends: for example, the second race of the year is in Sepang, a less severe engine circuit than Melbourne. As such, we are likely to use 60% engine potential at the first race, and 40% at the second. This is a new phenomenon for 2005, and the first races will bring important lessons in how best to manage our engine potential across two race weekends."

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