Focus on... The return to action
It's been four weeks since the chequered flag dropped on the manic Hungarian Grand Prix in Budapest. For two of those weeks, every factory has been shut away under lock and key but it will be the work conducted in the other two weeks which will cause the most intrigue this weekend. Honda arrives in Belgium with bold predictions about the potential of its upgraded power unit. Mercedes returns to the scene of last year's controversial collision between Lewis Hamilton and Nico Rosberg with ruffled feathers and fresh fears of losing one championship after Sebastian Vettel's brilliant win in Hungary, while Sauber finally has its hands on Ferrari's upgraded power unit.
While there will be several unknowns for the teams in Belgium, the biggest will be the revised starting procedures. Drivers will no longer be able to adjust their clutch bite point after leaving the garage on their way to the grid, and cannot be given information from the pit wall about which clutch settings to choose. As we saw in Silverstone and Budapest, slow starts from the front row equal entertaining races and the new rules add another dimension to this weekend's race.
In need of a podium
Kimi Raikkonen has been handed another year at Ferrari despite a less-than-satisfactory season so far. His poor form - he has less than half the points of team-mate Sebastian Vettel - fuelled speculation Ferrari could sign Valtteri Bottas as his replacement in 2016. But throughout the year it has seemed that Ferrari was looking for a reason to extend Raikkonen's contract for another year rather than a reason to end it and his performance in Hungary appears to have been enough to save his job. But Maurizio Arrivabene's words following the extension - "we expect this faith will be well rewarded" - is a clear message to Raikkonen: Performances must improve. A podium at his favourite circuit, Spa-Francorchamps, will be the perfect way to repay Ferrari's show of faith.
In need of points
There are several. Sauber has struggled since its brilliant start to the season with no significant upgrades brought to the car all year. It scored a solitary point in the closing stages in Hungary through Marcus Ericsson but will hope to see both its drivers battling for points on merit with its now it finally has its hands on Ferrari's upgraded engine. Pastor Maldonado has not scored points in the last two races and needs to start turning his raw speed into consistent results for a Lotus outfit yet to maximise its potential this season. McLaren will also be looking to build on the points it scored in Hungary, even though it is not expecting to get the best from its upgraded Honda power unit until F1 visits the twisty confines of the Singapore street circuit.
ESPN prediction
Last year Nico Rosberg took pole position in Belgium but, after seething for four weeks about the perceived injustice of Lewis Hamilton not heeding a Mercedes team order in Hungary, collided with his team-mate while clumsily trying to regain the lead on lap two. The German was reprimanded by Mercedes after the race and the incident triggered the form of Hamilton's life as he waltzed to his second championship. Rosberg will have a point to prove in Spa this year and ESPN is backing him to make that point in fine style by beating Hamilton to the flag.
Betting
Championship leader Lewis Hamilton is favourite to win the Belgian Grand Prix. You can find odds of 9/4 for Nico Rosberg, 11/1 for Sebastian Vettel and a longer shot of 16/1 for Kimi Raikkonen to win his fifth race at Spa. McLaren duo Jenson Button and Fernando Alonso are 8/1 and 9/1 respectively to be the first retirement.
Weather
The weather is notoriously treacherous in Belgium and the chance of rain could spice up the action this weekend. It looks set to be a sunny day for qualifying on Saturday, which should reach highs of 25 degrees, before forecasted showers for Sunday - which may well provide the best chance of a non-Mercedes victory in Spa.
Tyre talk
Prime: Medium
Option: Prime
Paul Hembery, Pirelli motorsport director, says: "We have the same tyre nomination for Spa as we did for the Hungaroring - which turned out to be one of the most thrilling races of the season - but the two circuits present a very marked contrast. Whereas Hungary was tight and twisty, Spa is open and flat-out, making it a favourite among all the drivers. We've got plenty of high-energy loads going through the tyres in many directions due to all the different forces at work, but ambient temperatures still tend to be quite low, so the soft and medium tyres represent the best compromise between performance and durability.
"Spa is a race where anything can happen, with a high incidence of safety cars and changing weather, so tyre strategy is important, as well as each team's ability to constantly read the race and react quickly to any opportunities that present themselves. The recent Spa 24 Hours - which is our biggest event of the year - featured more changes of lead than you could count, as well as a succession of incidents and safety cars in the first half of the race. That showcases just what a spectacular and unpredictable competition this amazing circuit can regularly provide."
Renault Sport F1
Renault Sport details the stresses and strains the Spa-Francorchamps circuit places on the main components of the power unit.
Internal Combustion Engine (ICE): Spa is the hardest circuit of the year for the Power Units. Over 65% of the 7km track is spent flat out, which translates as around 73secs per lap, the longest accumulative wide open throttle time of the year. The first period of sustained throttle is the climb from the La Source hairpin to the chicane at Les Combes. It takes around 25secs with the driver flat on the throttle throughout. The distance is only slighter shorter than a runway at Charles de Gaulle airport.
Almost all of sector three is taken flat out. From Stavelot through Blanchimont to the Bus Stop chicane, the Renault Energy F1 will be at wide open throttle for 20secs. The remainder of the throttle time comes from the bursts of power between corners.
The track's layout can be likened to a rollercoaster circuit where parts are loaded and unloaded in quick succession. The track drops over 40m from La Source before climbing over 80m back to Les Combes, equivalent to a gradient of 1 in 4. The descent compresses the internals but going over the crest of the hill, the vertical force is suddenly lifted and the parts unloaded, with the vertical forces switching to -3g. It can be equated to the feeling on a rollercoaster drop when your body feels compressed and pushed down into the seat but weightless when you go over a bump.
The altitude of Spa also affects fuel consumption. At its highest point the circuit is around 500m and the air is approximately 5% less oxygen rich than at sea level. With less oxygen going into the engine, around 1% less fuel is burned at Les Combes than at La Source.
Turbocharger: Turbo response in Spa is one of the critical performance factors. The majority of slow corners, for example the Bus Stop chicane, Les Combes and La Source are followed by a burst of throttle. Engineers will therefore look specifically at the engine maps to bring the delay in response as close to zero as possible. In fact, the time lapse between the driver putting his foot on the throttle and the turbo kicking in is now around 0.2s
The turbo will be rotating at close to its maximum to keep pace with the high rotational speeds of the ICE. The altitude will further increase rpm. At its most extreme the turbo will be spinning at more than 95,000rpm or over 1,500 revs per second!
MGU-K: Spa is one of the most demanding tracks on the MGU-K. Each of the braking points comes after a long burst of power so the energy dissipated through the brakes is enormous. The best opportunity for the MGU-K to recover energy is the Bus Stop chicane, which the driver approaches at over 300kph and brakes down to just 75kph.
At La Source, car speeds drop to just 70kph and engine revs to around 8,700rpm. The combination of MGU-K, ICE and brakes need to dissipate 2MJ of energy during this braking event - front brake temperatures will rise by more than 300°C to achieve this, even though the MGU-K is at the full recovery allowed by the regulations.
MGU-H: Sector two has the majority of corners and is therefore the least power sensitive part of the track. This pushes us to recover as much energy as possible on the MGU-H whilst maintaining good turbo response. High-speed flowing corners such as Pouhon and Fagnes are the best opportunities and will feed the recovered energy to the MGU-K and ICE on the next period of throttle through Blanchimont.