Four nitro-class drag races feature 320 mph top fuel dragsters, Prostalgia Nitro funny cars, Nitro Harleys and fuel-altered vehicles starting at 7 p.m., Friday and Saturday, March 25 and 26. Fanfests start at 5:30 p.m. both nights. A 30,000 horsepower Super Shockwave jet truck and the Grave Digger monster truck meet in an exhibition challenge. $25. Call 762-9700, or visit nitrojam.com for more information.