Bahrain Grand Prix: Renault preview
18 April, 2012
Apr.18 (Renault Sport F1 Press Release) The Bahrain Grand Prix will be the fourth event on the 2012 FIA Formula One World Championship and takes place at the 5.412km Sakhir International Circuit. This year, the circuit layout has reverted to the shorter 2009 layout and not the configuration last raced in 2010.
There have been seven editions of the race, with Renault F1 Team winning in 2005 and 2006 with Fernando Alonso. Red Bull Racing-Renault’s Sebastian Vettel also started from pole in 2010.
Bahrain Grand Prix facts and figures
Engines are at full throttle for 50% of the lap in the race and 57% in qualifying. The 1000m pit straight leads into another 500m straight before a short straight between 10 and 11 and the final long drag between 13 and 14. As a result Sakhir sits in the middle of the table for the demands put on engines. With the DRS this year, the top speed down the pit straight will be around 310kph.
The twister back section from turns 4 to 8 and 11 to 13 shift the emphasis more into delivering mid-range torque. A smooth torque curve can help in this sector as it gives the driver a greater choice for gear ratio selection. With a wider power curve, the engine is able to pull a selection of gears instead of only the optimum, meaning that the teams do not have to opt for a set of race or qualifying ratios — one set does both. Low speed pick-up will be important at the exit of turns 1, 4 and 8.
High ambient temperatures have an obvious effect on cooling but there is also an engine acoustic tuning effect. When air temperature increases, the speed of sound also increases, so the length of the trumpets (which regulate the intake of air into the engine via the airbox) need to be increased as well for perfect engine tuning — very similar to the tuning of an instrument. Under the regulations teams are allowed to homologate three sets of different length inlet trumpets. The longest trumpets will be fitted for this event for optimal engine tuning, allowing the sound pressure waves to arrive at the inlet valve at the perfect time, therefore inducing more air into the engine and creating more power.
Ambient conditions in Sakhir are typically in the low 30s, but contrary to Sepang, this is a dry heat. The drier, less humid conditions are less detrimental to engine power, but teams will not benefit from an increased cooler efficiency, as they did at Sepang. This means that the bodywork may have to be slightly opened to aid the cooling configuration, but chassis engineers will no doubt be trying to limit the openings to negate any detrimental effect on the aero performance.
The circuit is located in the middle of the desert, meaning dirt and sand are often blown onto the racing line. This may be ingested into the inlets and cause damage to the internals of the engine. Only one air filter may be used under the engine freeze regulations so Renault Sport F1 has developed a filter that can be used throughout the year. This has been developed to deal with the ‘high grit’ races such as Abu Dhabi, Bahrain and Hungary as well as the clearer races without any performance drop off.
Due to the higher ambient temperatures, tyre degradation is expected to more critical in Bahrain than one week ago at Shanghai. As such, it is important that the driver can accurately modulate the torque to reduce wheel spin and prolong tyre life. With tyre degradation, the drivers may also prefer to use engine support when braking to stabilise the rear end of the car. This prolongs the effective tyre life, but comes at the expense of increased fuel consumption — and thus a higher race start weight — as well as a small increase in coolant temperatures.
The drivers’ view:
Vitaly Petrov, Caterham F1 Team:
Bahrain is where I made my F1 debut back in 2010 so it’s a track that means a lot to me. From the driver’s point of view it’s a pretty technical circuit and getting the Renault RS27 to deliver the right torque level both into and out of the corner is crucial to getting a good balance to nail every apex. Fifty percent of the track is also long straights so top line power and effective KERS can also help in gaining positions.
The engineers’ view:
Head of Renault Sport F1 track operations Rémi Taffin gives his thoughts on Sakhir:
The track is pretty tough on the driver, due to the heat and also the layout. On some of the corners coming out of the straights the driver will be pulling very high g-forces, but the twisty back section requires a very precise set-up so there’s not much chance to relax. For the engine, however, it’s not too severe. It is around 50% – 60% full throttle, depending on qualifying or the race, so sits in the medium bracket for engine usage and severity. Only the ambient conditions, such as the lack of water content in the air and the sand blown onto the track, make the severity worse, not the layout of the circuit itself.
That said, Friday in Bahrain could be one of the busiest Fridays of the whole season for us. This season we’ve seen Fridays need more work than before. The exhaust blown diffusers helped us with drivability last year, so trying to dial the engines in for every corner means we have to look a lot more at the torque levels and the settings. Furthermore, the new rules mean we can’t play with as many parameters as we did last year, so we’ll have to be smarter and use the possibilities open to us. On a track layout we haven’t used for three years, it is going to be very hard work.
All Renault powered drivers will be using the engine from China, save Vitaly Petrov who will use the unit from Malaysia. We are positive about the challenge ahead of us and hope we can deliver the correct response and drivability to our partners.