NASCAR announced on Monday that the Sprint Cup Series will increase the size of the carburetor restrictor plate from 63/64-inch to 1 1/32 inches for the July 3rd Coke Zero 400 at Daytona International Speedway.
The new openings will be the largest since one-inch openings were mandated back in 1988, the first year that the plates were implemented for yearly use.
A restrictor plate is a thin metal plate with four holes that restricts airflow into the engine. It reduces horsepower to keep speeds down at Daytona and Talladega Superspeedway. With the larger openings, more air will be allowed into the engine, making the cars faster.
NASCAR Vice President of Competition Robin Pemberton said,
We think this will be a needed boost due to the additional drag we’ve picked up since switching from a rear wing to a rear spoiler.
Earlier this year, NASCAR decided to switch from the rear wing to a spoiler  to make the racing better and to make the COT’s appearance closer to that of the production models.
The Coke Zero 400 will be the last race on the current racing surface at Daytona, as the track is set to be repaved  before the 2011 Daytona 500.