In a statement on Tuesday, Ferrari said: "We have now made in-depth tests in a wind tunnel in the presence of independent experts who confirm that the turningvanes used in Malaysia have made no difference whatsoever to the performance of its cars."

Earlier, Formula One supremo Bernie Ecclestone criticised the decision by the sport's governing body to disqualify both Ferraris from the race.

Ferrari driver Eddie Irvine: "It was perfect except for the little aggro after the race"

He said the move by the FIA was detrimental to the image of the sport and insisted the title contest should be decided in the final race of the season in Japan.

But Ecclestone has no power to reverse the decison and resurrect the Malaysian result.

Eddie Irvine had taken the lead in the title race when he was disqualified

The drivers' championship was thrown into chaos when Eddie Irvine and Michael Schumacher had their points deducted after it was found that their Ferraris had broken regulations on the size of their barge boards.

McLaren's Mika Hakkinen, who finished third in Sepang, was promoted to race winner and has subsequently been declared "provisional world champion".

But the outcome of the title race is still to be decided, after Ferrari appealed against the disqualification.

A special independent court set up by the FIA will rule on the appeal in Paris on Friday morning.

F1 needs 'great finish'

Ecclestone described the decision to disqualify Irvine and Schumacher from Sunday's race as "nonsense" and urged the FIA (Federation Internationale d'l'Automobile) to loosen its restrictions.

The row has dominated the press in Italy, the home of Ferrari

"What happened in Malaysia is bad for the sport," he said.

"I would like what the public want - to see a great finish in Japan."

Ecclestone added: "I have campaigned for years that the Formula One rules and regulations are too tight.

"It is bad for the sport. The public want to see a great finish to a great championship.

"It is a shame if the world championship could be decided by someone quite junior who has made a mistake in the factory."

Despite being the power behind the Formula One throne and a vice-president of the FIA, Ecclestone has no influence on the court of appeal's decision.