NASCAR officials have issued further changes to the size of the restrictor plate teams will run during Thursday's Gatorade Duel qualifying races for the Daytona 500.
Following the Budweiser Shootout, where cars race in two-car tandems for almost the entire event, NASCAR issued new restrictions to the cooling system on Sprint Cup cars, reducing the maximum size of the front-grille opening and introducing a pressure release valve for radiators.
Hoping to make sure speeds remain in control, officials have now issued a new size for the restrictor plate, bringing it down to 57/64th's of an inch, taking 1/64th away, which equals almost a 12-horsepower decrease. The change also means teams will probably run lower rpm after many were well over the 9000rpm in the draft on Saturday.
Many teams had already anticipated the measure, which has come as no surprise. They will all get the chance to try out the new cooling package during Wednesday's practice sessions – weather permitting as there's been intermittent rain today at Daytona – and they will race with those parameters during the Gatorade Duels.
"We've got a race under our belt, so everybody knows what they've got," said Sprint Cup Series Director John Darby. "We've been in discussions with a lot of the engine builders in the garage and their concern is that their rpms are too high and the easiest way to fix that, or to bring it back a 100rpm or 200rpm, is with a very small plate change.
"They deserve that help and gives us a little help with the speeds as well. The plate change is twofold, but more importantly is to bring engine builders into a better comfort zone so that they don't have to worry about their engines having failures during the 500."
Although officials expect all the changes to address the long two-car bump-drafting that prevailed in Saturday's race and the rising speeds that soared at 206mph lap averages, NASCAR could introduce further changes if needed.
"We've got a long way to go until Sunday," Darby added. "The goal is to get everything under control so that we can put on the most exciting Daytona 500 that everybody's ever watched. We'll do what we have to do to get there."