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Exhausts cost performance - Allison

ESPNF1 Staff
September 28, 2011 « Fernandes hails Renault 'stability' | Hamilton drive attracts 40,000 »
James Allison says the Renualt team struggles to set the R31 up because it is "extremely unforgiving" © Sutton Images

Renault technical director James Allison says the front-exiting exhaust concept was the main reason for the team's poor performance in Singapore.

While the innovative design saw the R31 be very competitive early in the season, it has gradually fallen off the pace, and is notably weak on the tighter circuits such as Monaco, Hungary and Singapore. Allison told the official Renault website that the concept costs the team performance in slow speed corners because of a lack of downforce at the rear of the car, heavily reducing traction.

"We know from our experiments with rear blowing exhausts earlier in the year that they do offer a lot more rear downforce - especially at high rear ride heights," Allison said. "We know that slow speed tracks allow the rear to be held up high in all the corners and we know that rear downforce is a prized asset for coping with the traction demand at these tracks.

"We also know that the forward exhaust, by contrast, performs more strongly once the rear ride height starts to compress - something that cannot be avoided in medium and high speed corners. It is probably reasonable to conclude that this is the basic mechanism behind the way that we shed so much competitiveness at slow speed tracks."

Allison also said that the car was difficult to set up, and even more sensitive to low speed corners.

"Even at Spa and Monza, where our performance was acceptable, we still had to tweak the aerodynamic setup during the weekend. Our car is very sensitive and extremely unforgiving of even the slightest geometric misalignment. This weekend, we were plagued by rear wing and floor issues that all seem to be even more sensitive at very low speeds than they are at the higher speeds where our car is more comfortable."