Formula Renault 3.5 team ISR has taken responsibility for Sam Bird losing ground in the title race after a difficult weekend in Hungary.
Mercedes Formula 1 test driver Bird went into last weekend's round at the Hungaroring just five points behind championship leader Robin Frijns, but that gap increased to 27 after ISR struggled to get on top of car setup.
Team boss Igor Salaquarda said: "This weekend was a very difficult one for ISR. We really struggled with the set-up of the cars and were never able to give our drivers a package that they could compete properly with."
He also praised Bird's efforts over the weekend, after the Briton managed to salvage a fourth place finish in race two.
"Sam's issues were further compounded by engine problems that led to it being changed on Saturday," Salaquarda added. "So the fact that he managed to get a point on Saturday [by finishing 10th] and narrowly missed out on a podium in race two is quite exceptional and testament to his considerable talent and fighting spirit."
Bird admitted that the championship situation means that he will now need a bit of good fortune to catch Frijns.
"We were lost, absolutely lost," he said. "The guys are working really hard, but it seems like we have a really small setup window at the moment.
"I'm going to need a bit of fortune, but we are going to need to work hard to make the car competitive too. We can still do this if we can come up with a reasonable car. We're trying everything we can but it's just not going our way. It's going to take a big effort from everyone."