GRAND-AM: DP Balance Of Performance Continues

Friday, December 16, 2011

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Courtesy of Speed.com

A new era of the GRAND-AM Rolex Sports Car Series begins at next month’s 50th Rolex 24, as a new breed of Daytona Prototypes will be unleashed in what’s being touted as one of the most significant makeovers in the series’ 12-year history.

While a brace of DPs will be sporting sleeker-looking, all-new bodywork designed by Chevrolet and Riley, existing second-generation cars have been grandfathered into competition for next year.

It’s no doubt created a challenge for the series’ technical chiefs in balancing the two different specifications of Daytona Prototypes, but as GRAND-AM VP of Competition Dave Spitzer tells SPEED.com, the process has been going to plan.

“We came off three days of [wind tunnel] testing at Windshear [prior to the December Daytona test], where we tested the new Corvette Daytona Prototype and one each of the current-generation Riley, Dallara and Lola,” Spitzer explained.

“So we ran through a battery of testing, looking to determine the inherent performance characteristics of all the cars and the affect of the normal tuning you do, like rear wing, spoiler, wickers, and things you can do in the front.”

Spitzer said they also introduced aerodynamic devices that GRAND-AM could use to execute Balance of Performance adjustments between the new and old cars.

With the new-gen DPs featuring a significantly reduced greenhouse, yet the extravagant Corvette DP bodywork producing different levels of downforce than its predecessor, the series had first find out the optimal methods of adjustments before putting them into action.

“What we were looking for was the ability to, for instance, generate drag without having an impact on downforce,” Spitzer explained. “That's not easy to do because most things have a coupled affect.

“We tested a series of devices in the tunnel and learned a lot about what it does to the aero balance overall. We then tested some of those pieces [on the track last week]. There's no final conclusion at this point.”

Spitzer would not go into detail of what the devices are, but alluded that most of the adjustments would be made in the rear of the car. He also said the Balance of Performance could involve both the Gen-2 and Gen-3 cars, instead of slowing down or speeding up just one spec of car.

The quickest Corvette DP at last week’s test was about 1.5 seconds slower than the pace-setting Gen-2 machines.

"We're just trying to get the whole class balanced,” Spitzer said. “One of the fundamental goals of the new generation of prototypes was to allow a corporation like General Motors to build that beautiful body and not feel threatened that if it was losing an efficiency in some area, that would be the end of their program. That's what it it's all about.”

With Riley’s new non-brand specific MkXXVI set for its on-track debut next week with Michael Shank Racing, Spitzer said the second new-look Daytona Prototype will go through the same wind tunnel and on-track testing process prior to the “Roar Before the 24” test at Daytona next month, where he expects a finalization of BoP adjustments to be issued.

Nine Gen-3 DPs are expected to take the green flag in next month’s 50th Rolex 24, with nearly the same number of grandfathered cars slated to be on the grid as well. While Spitzer reaffirmed that existing Gen-2 cars will be allowed to compete throughout 2012, it’s unclear if GRAND-AM will extend the homologation past next year.

"It’s down to what the team's needs are and what their long-term view is,” he said. “We're trying to move people to the Gen-3 as aggressively as we can but we respect that in having that way to get in and make that transition is very valuable. And we want those cars to remain competitive.”

Spitzer confirmed the Corvette and Riley bodywork will be the only new-generation designs for the start of the 2012 season but has remained hopeful to introduce additional bodywork over the course of next year.