The Aussie admitted the set-up changes made after the first session to the Renault car did not work: "We looked alright (after FP1) and I felt there was some easy places to improve in lap-time.
"But the afternoon, I felt we didn't really evolve a bit with the track. We made some changes but probably not for the best so at least we learned from that. Going back to what we know is OK but we know we still want more than that.
"We'll make some changes for Saturday, hopefully they work. I'm still optimistic that we can do better than what we did today."
Ricciardo believes the main area that his team can improve, is the car's ability to get over bumps.
"Obviously it's quite a bumpy circuit and you've got to have the confidence to get it on the kerbs and that," Ricciardo continued to RaceFans. "I think we could be better in that area, riding the bumps and the kind of warp of the track better.
"(There's) a few things maybe we can do with suspension and we'll look into (it). Otherwise it should all kind of come a bit easier after we sort that out. I think Nico (Hulkenberg) and myself still have a bit in the bag as well but we've obviously not got a second in us so we've got to find a bit more in the car and I think we'll get a bit more out of ourselves as well."