Renault has reverted to forward-facing exhaust for Nick Heidfeld's car

As AUTOSPORT revealed, Renault wanted to experiment with a Red Bull Racing-style rearward exhaust configuration to see if it would make its blown diffuser more effective and deliver better lap times.

A prototype version tried out in a recent straight-line test at Duxford delivered some promising results, and the team elected to further evaluate this version - which is 4kg heavier than it should ideally be because it is not fully made on carbon fibre - on Heidfeld's car at the Nurburgring.

Despite not being familiar with the concept, Heidfeld was able to match the times of Vitaly Petrov, who was sticking with the forward-facing exhaust concept.

However, the team feels that the rearward design still needs more evaluation before being put into race action - so it elected to revert Heidfeld back to the forward facing exhaust layout while it ponders its next move.

Renault team principal Eric Boullier told AUTOSPORT that despite not running the new exhaust, the team was upbeat about the progress of that and other updates added to the car.

"The feedback is positive because it was the first day of using it, in terms of balance and driveability of the car," he said. "It looks like the car is working much better now."

Boullier believes that the team was on course to deliver some good steps forward in the next few races, with development in its upgraded 60% scale wind tunnel now advancing at a quick pace.

"We have a performance indicator where we follow our development," he said. "We know we struggled with our development for a couple of months for many reasons, and now especially the aero development has been back to a very aggressive slope now for three or four weeks.

"But there is a delay, we know, between finding downforce and producing the parts for the track."