Hallam, 56, had been at McLaren since December 1990 and in his career worked with drivers such as Ayrton Senna, Nelson Piquet, Nigel Mansell, Michael Andretti, Gerhard Berger, Kimi Raikkonen, Mika Hakkinen and most recently Lewis Hamilton.
Hallam will now oversee the NASCAR Nextel Cup activities of Michael Waltrip, David Reutimann and Australian Marcos Ambrose.
"It would have been easy to stay at McLaren until I retired," Hallam said. "But what attracted me to Michael Waltrip Racing was the opportunity to work with a young team and, in particular, to be part of the continued development and growth of the multi-car Cup operation as they strive to provide the best equipment and support for their teams. This is a great opportunity to join a closely knit team who are looking to build success by harnessing Toyota engines and technical support to build cars at a level where we can improve upon the tremendous foundation that has already been built."
Hallam's first taste of NASCAR came in 2007 when he visited a Nextel Cup race as a guest of a Toyota executive.
"I realized there is life outside of Formula 1 and it is very exciting, different and challenging," Hallam says. "It didn’t take me long to realize I wanted to be a part of that." Grandprix.com