Red Bull Racing team boss Christian Horner has admitted that the Milton Keynes-based outfit needs to raise its game over the remaining six races of the Formula One season if it is to remain in the battle for fourth place in the constructors' championship.

RBR heads to Spa-Francorchamps for this weekend's Belgian Grand Prix having struggled to match rivals such as Toyota and Renault in recent races, with a couple of disappointing outings in Budapest and Valencia highlighting a demise that began when Mark Webber swapped a front row spot at Silverstone for the back of the field after a first lap spin.

"After a very strong first half of the season, the team has endured a very frustrating past few weeks, with no points scored in the last four races," Horner confirmed, "The next few circuits, in particular Spa, should play to the strengths of the RB4 package, so it is extremely important that we reverse this trend and get back on terms with Renault and close the gap to Toyota."

Horner says that the team has used the summer break and post-race analysis after the extremely disappointing Valencia weekend to try and pin-point areas of weakness with its car, which appeared a threat for points at almost every round up to its home grand prix.

"Valencia did not play to our strengths, but we are convinced we can bounce back," the team boss commented, "Over the past six weeks, we have analysed our performance in great detail and that analysis reveals the chassis is working well and we have pushed very hard in the factory to improve in all areas.

"Tyres are proving to be the biggest factor at the moment. Over the past couple of months, Toyota has looked very strong tyre wise in the higher temperatures. It's not a case of our rivals suddenly 'bolting on' more performance. It's down to tyre usage and they have handled that better than us. We have understood why this happened and I feel we can get on top of this situation and return to our earlier form for the final third of the season"

"Apart from anything else, there are a lot more high-speed corners than in Budapest or Valencia! We had a good test in Monza and, although that was aimed primarily at the Italian Grand Prix, the results of the test answered several fundamental questions about our package.

"Apart from the track characteristics, the weather always plays a crucial part in Belgium, therefore we will need to be particularly sharp operationally and in terms of strategy, dealing with the fact that, sometimes, half the track can be dry and the other half wet. We need to go there and attack the weekend, we need both our drivers to be on top of their game, aiming to finish in the points.

"At the moment, the section of the grid that includes, BMW, Renault, Toyota, ourselves, Williams and now, Sebastian Vettel, is extremely tight and, as we've seen at the last few races, one tenth of a second can make the difference between four grid positions. Even with the long lap at Spa, I think we can expect a very tight grid, while the early Autumn weather, with the race taking place a weekend later than usual, can add further unpredictability."

Despite Horner's claims that tyres have been the main factor in the team's recent downturn, fingers were being pointed at the performance of its Renault engines after the Valencia weekend, with not only RBR, but also the 'factory' Renault team, struggling to keep pace with their rivals amid concerns that the adhering rigidly to the 'engine freeze' had affected the RS28 more than other V8s.

"It was difficult and disappointing," Fabrice Lom, the man responsible for Renault's V8s at Red Bull Racing, admitted, "The cars did not have the necessary performance to run at the front and we realised that as soon as we took to the track on Friday. Of course, we improved and found speed over the weekend, but not enough, so we finished without any points for the fourth consecutive race, which is hard to take.

"Initially, you would think that our competitors have improved faster than us. However, I think that the explanation is elsewhere, for one simple reason - the Toro Rossos were in front of us in Valencia. Their cars are similar to the Red Bull Racing cars, but they are a development step behind us, and we were in front of them during the start of the season.

"Our poor performances recently are difficult to explain, but our preparation for Spa will involve trying to understand what did not work in Valencia. We feel there is certainly some more performance in the car and we need to develop that as much as possible. In theory, our cars should be more competitive on this more flowing type of circuit."

The desire to find increased performance, at both this weekend's race in Belgium and next Sunday's Italian Grand Prix, will have to be tempered by the fact that both tracks will place higher strain on the engines than the likes of Budapest and Valencia.

"We will use two new V8s, which is not ideal for such demanding back-to-back races as Spa and Monza, so it will be tough," Lom continued, "In comparison with the last two races, the tracks to come are much more demanding. We must try and look after the engine whenever possible, without compromising performance in Belgium. I wouldn't be surprised if we see some retirements towards the end of the race, especially if some of our competitors, who are unlikely to score points in Spa, prefer to
race in Monza with a fresh V8."

Despite the problems, however, Horner insists that the development of next year's Red Bull challenger will not be compromised by the desire to maintain the pursuit of fourth place in 2008.

"The whole group is working extremely hard to balance its resources between on-going development of RB4 - currently more important than ever, given the performance downturn we've just been discussing - and the work on the 2009 project," he admitted.

"However, right from the end of 2007, we planned for RB4 development to continue to the end of the 2008 season and, therefore, the pressure to make up the ground lost in recent weeks has no impact on our work on next year's car. The team has worked well together putting in concerted effort and man-hours to understand and find solutions to our recent problems , so we are going to Spa in fighting mood, determined to come away with some points."