FAST Engine Control System XFI - Sportsman TBmost users will use Speed Density but the Alpha N option is specifically added to serve sportsman drag racers looking for absolute consistency. The FAST XFI Sportsman System features full tables to monitor fueling, acceleration fuel, timing and air fuel targets, while full function data logging is also included. It supports both naturally aspirated and boosted applications up to 5 BAR, is compatible with wet nitrous and has nitrous timing retard