Tonio Liuzzi is hopeful of a stronger performance on Saturday despite a problem with his car's top speed reappearing at Silverstone.
The Force India driver had switched to a different chassis after being hit with the problem earlier in the season, and he was pleased with the progress made.
The issue, however, reappeared in Friday's practice for the British Grand Prix, where the Italian finished down in 15th place.
Despite that, Liuzzi is confident of finding more performance tomorrow thanks to the introduction of new components not used today.
"We will keep updating tomorrow," Liuzzi told AUTOSPORT. "Today we saved some of the parts because we don't have many of them, so to save we will put them on tomorrow morning. Overall, the car is responding quite well.
"But as I was saying in Valencia, we need to wait until this race to understand the car and, in fact.
"We face here again the top-speed problem so we have to understand it. We believe that part of it is because of the F-duct. But overall the balance of the car is not bad and we are in good shape. In the high-speed we're good, and in the new part which is really slipper it is responding well.
"We're looking forward to tomorrow which should be even better with the updates."
He said the top-speed problem was quite a significant one on a fast track like Silverstone.
"It depends on the straight, it can be from two to 4-5km/h so it's quite a significant difference by the end of the lap especially because there are some long straights here," he said.
"But we saw the the stallable rear wing was not working properly and we need to understand whether it's because of that or if it is the same as the issue that we faced at the beginning of the year with this chassis."