In March 2005 , around 8,000 Christians went to the stadium . This was the largest act of Christian worship in Suffolk since American evangelist Billy Graham used Portman Road on part of his tour in 1984 . In March 2005 , around 8,000 Christians attended a gathering at the stadium , the largest act of Christian worship in Suffolk , since American evangelist Billy Graham used Portman Road on part of his Mission England Tour in 1984 .