Speed will drive KHI's No. 33 in the Aug. 6 race at Iowa Speedway and Aug. 20 road course race in Montreal.
Speed was replaced at Red Bull Racing this season by Kasey Kahne, who will drive the No. 4 for one season before moving into the No. 5 at Hendrick Motorsports in 2012.
Speed finished 30th in the Cup standings last season and 35th in 2009, his only full schedules in NASCAR's premier series. He drove in 13 Nationwide races in 2009, collecting eight top-10s and 10 finishes in the top 13.
Speed's lone win in NASCAR's top three series came in a 2008 Truck Series race at Dover.
David Newton covers NASCAR for ESPN.com. He can be reached at firstname.lastname@example.org.