Renault says Belgian Grand Prix upgrades will determine results for rest of 2011

As negotiations continue behind the scenes to decide whether Nick Heidfeld or Bruno Senna races for the team at Spa, amid suggestions the matter could now go to court, the engineering staff are focusing on delivering a major update to the R31.

The developments, which have delivered positive figures from the wind tunnel, include a new floor, revised forward-facing exhausts, modified rear suspension and other aerodynamic updates.

Team principal Eric Boullier said that the team's chances of overcoming Mercedes for fourth place in the constructors' championship would rest on how good the upgrades are.

"We need to catch up with Mercedes, who have replaced us in fourth position," he said in a team preview that failed to mention its driver line-up. "In Spa we will see if the upgrades are enough to do this, but I hope they will be.

"We are now at a point where we switch a lot of our resources to next year's car, which of course adds new challenges. Crucially, we need to see what impact our upgrades have at the forthcoming races in Spa, Monza and Singapore.

"It is this, above all else, that will be the key indicator in how fruitful the remainder of our season is. We're back and we're looking forward to finding out."

Despite the tricky driver situation that the outfit is refusing to comment on, Boullier says the team is revitalised after the summer break and eager to recover the ground it has lost in recent races.

"It's good to be refreshed, to recharge the batteries for what lies ahead and to come back and finish the business," he said.