Renault's guide to Hockenheim set-up 22 Jul 2005
Renault race engineers, Rod Nelson (chassis, for Fernando Alonso) and Fabrice Lom (engine, for Giancarlo Fisichella) explain the technical requirements for achieving a fast lap around the Hockenheim circuit, setting for this weekends German Grand Prix.
Rod Nelson: While we run much higher levels of downforce than we used to in Hockenheim, this by no means makes it a high downforce circuit. For ideal lap time, we would run medium downforce levels but the requirement to achieve competitive top speeds on the long straight and to be able to overtake or defend a position into Turn 6 means we in fact run medium-low downforce - similar to Canada levels. This slightly compromised' set-up is reminiscent of Indianapolis, which also forces us towards a set-up favouring straight-line speed over grip through the tighter sections.
Mechanically, we are able to run the cars quite soft as there are no significant high speed changes of direction on the circuit. Front to rear, we run a forward mechanical bias ie: a stiffer front end, in order to get good traction out of the slow and medium speed corners and keep the rear stable under braking. Indeed, with the braking zone into turn 6 being the main passing opportunity, braking stability is something we work hard to get right. The track surface is generally quite smooth, and ride heights are only limited by the amount the car touches the ground into turn 6 at maximum speed.
Temperatures are usually very high which can potentially give a number of problems. Firstly, with the heavy traction demands it is very easy to blister the rear tyres as track temperatures are always high; and secondly, we must manage our cooling level carefully to avoid overheating, either running alone or in traffic. However, with the R25 this is unlikely to be a problem as it possesses particularly effective cooling.
The stadium section also gives both the drivers and engineers plenty to think about. With relatively low downforce levels, the drivers constantly complain of poor grip throughout the sessions, although the banking in T13 certainly helps this. T12, on the entry to the stadium, is probably one of the trickiest corners in Formula One - the circuit narrows significantly between entrance and exit, and the drivers always run quite wide to use the traction available on an uncovered access road that runs across the circuit. We often see cars in the grass or even gravel at this point of the circuit, and it is relatively easy to damage the car. Equally, the high number of corners in a short section of the circuit means brake, oil, water and gearbox temperatures can climb quite high.
Fabrice Lom: Even in its revised configuration, Hockenheim is a serious test for a Formula 1 engine. Although it no longer features the long straights of years past, it is, on average, the most demanding of the season so far for the V10: the average engine speed around the lap is high, 62% of the lap is spent at full throttle and the single longest period spent at full throttle is exceeded only by Indianapolis.
These characteristics obviously demand a strong, powerful engine - but the nature of the circuit layout also imposes the additional requirement of having an engine that pulls well from very low revs, as the hairpins are some of the slowest corners of the entire season. Good torque is also an advantage under acceleration out of these slow and medium speed corners.
Conditions are often very hot in Hockenheim, and the result of high temperatures is a phenomenon known as engine acoustic offset'. This means that the engine develops its peak power at higher revs, and obliges us to use as many revs as possible in order to achieve optimum performance - a difficult exercise in reliability terms on such a demanding circuit. However, this is where our new C spec engine - with its ability to maintain peak revs for longer in race conditions - will play to our advantage.
Of course, the engines will be the same units as used in Silverstone and, in spite of a hard race, both ran impeccably in the UK and are in good condition for the coming race. They can expect a hard weekend, but some respite may come in the closing stages of the Grand Prix - the race pace often drops in the final laps owing the circuit's severe demands on the tyres, and in fact the average race engine speed at Hockenheim is only the fifth highest of the season (compared to the second highest in qualifying trim).