The former world champions are the only team yet to score a point after three races, their car slower on the straights than last year without having made significant gains in other areas to compensate.
"There is a cure," Sirotkin told reporters at the Azerbaijan Grand Prix on Thursday, agreeing that the problem was mostly aerodynamic.
"We found something which is not really giving us exactly the performance and numbers we were expecting, which affects basically all the way how the car works.
"Now we are flat out to solve this and we think that once this issue can be solved, the car will open up and work as it was originally planned."
His Canadian team mate Lance Stroll, who was on the podium after a chaotic race in Baku last year, said the team had expected to lose some straight line speed due to the bulky new halo head protection device and a more aggressive design.
"Unfortunately we haven't recovered enough of the cornering speed to compensate for (losing) that straight line speed this year," said the teenager.
"We don't have the handling benefits that we were looking for...we've lost a good chunk in our strong point and we have not gained enough in our weak point."
Sirotkin, a rarity as a driver who also has an engineering degree, said he was relishing the challenge despite all the frustration.
"Yes it’s a tough moment for us but personally... I am enjoying that it gave us a very strong challenge," he said. "I think there’s a very good spirit and a clear and obvious task ahead of us.
"The way we are all trying to solve it has really united the people and I am really enjoying being at the factory, staying together with the team, fighting every single day to solve the problem.
"It’s not that nice to be not the quickest car out there but I am very confident that one day we will get over it and that day I will be very proud for all of us that we stayed united and worked harder than anyone else to get on top of it."
As far as Sunday was concerned, Sirotkin hoped for a similar amount of chaos as last year in a street race with the longest straight on the calendar but also some tight and twisty corners.
"So many things can happen in this race and from where we are, at the moment, the more that happens the better it is for us," he said.
(Reporting by Alan Baldwin, editing by Ken Ferris)
