Sauber brings 'significant' upgrade to Japan in effort to boost constructors' position

The Swiss outfit has slipped behind Force India in recent races, and is now under pressure from Scuderia Toro Rosso in a fight for seventh place in the constructors' championship.

And having scored just one point in the last four races, new aerodynamic developments have been added to its car in Suzuka to help lift its performance.

Sauber CEO Monisha Kaltenborn said the hope was for a decent step forward in performance - which was vital to its campaign.

"There is an expectation of a significant step," she said when asked by AUTOSPORT about the expectations from the new parts.

"We had always intended to have a major step in Suzuka, like we had last year, but it has gained in importance seeing how our direct competitors have been doing.

"Now we have to fight for the position we have, and make sure the others stay behind us."

Team principal Peter Sauber conceded in Singapore that the outfit was paying the price for the points it lost at the start of the season with a wing irregularity in Australia, and Kaltenborn admitted that the team's position was not ideal.

"Had we not had the opening of the season and the gearbox issue we had in Monza, it could have looked a bit different," she explained.