Engine management relay with one large and 1 small socket. this black box sits on top of the servio mounting bracket and should have a sticker on it with the part number YWB10022, for SPI only--see YWB100970 for MPI
If done properly, converting your Mini to EFI can have many benefits. The EFI Engine Control Unit (ECU) can control all aspects of the combustion of the air/fuel ratio under all conditions. For each and every load point throughout the rev range that the engine may experience, the EFI ECU can calculate the optimum timing and delivery of fuel as well as precisely when ignition will take place by supplying spark at exactly the right time in order to maximise power and torque.