WASHINGTON — Get ready to start your engines, DC. Officials unveiled the 1.66-mile circuit route Monday, where race cars will be zooming around the National Mall in August for the Freedom 250 Grand Prix in celebration of America’s birthday . The seven‑turn layout features views of the Washington Monument, US Capitol, the Smithsonian National Air and Space Museum, and part of Pennsylvania Avenue, IndyCar announced. “This was a team effort,” Transportation Secretary Sean Duffy said. “It’s Penske,