He started racing in 1973 at the age of 17. His first car was a Hillman Imp, which was formerly owned by Andy Slaughter. His first race was at Silverstone in Production Saloons where he finished third in class. Over the years he has driven over 50 different types of cars, ranging from Minis to a Mercury Cougar. The Mazda RX7, Honda Prelude and his current Escort WRC have been three of his more successful. His quickest car must be a Ford Sierra with a Porsche 956 engine. It was capable of over 180 mph. The mid 1980s to early 1990s saw some of the wildest saloon cars roam the English circuits in Thundersaloons. Birley drove cars in both class A and class B, including Ford Sierras, Ford Escorts, Mitsubishi Starion, Mazda RX7, Opel Manta, Honda Prelude with such talented drivers as Andy Rouse, Dave Brodie, John Brindley, Richard Piper and Mike Wilson. During this period he also got to drive various other cars ranging from Peter Bevan's Ford Anglia, Sean Brown's Toyota Corolla and Ford Sierra, Frank Cundell's BMW M3, John Harrison's Sunbeam Tiger and Chris Weedon's version, Tim Bowles' Camaro and Nick Torregani's Mustang. By 1995 most of the saloon classes were in decline as was his enthusiasm. It took an offer from Mark Burnside to share one of his MGs at Lydden to get him racing again. There followed some successful forays into Europe, with Frank Cundell's Escort Cosworth and Dave Thomas's Ford Capri. he then purchased a Ford Escort WRC which has turned out to be one of his most successful cars. The four wheel drive making it virtually unbeatable in the wet. During his 30 or so years of racing Birley has won over 415 races. He has had a reputation for being a bit of a 'Pot Hunter'