LINK ECU - G4X AtomX Wire In ECUSmall, but mighty! The AtomX can control up to 2 rotors or 4 cylinders with sequential injection and direct spark. Or, it can be used for up to eight cylinders using batch fire. Now featuring Knock Control. This makes it ideal for naturally aspirated engines that just need a re tune and don't need all the extra sensors and features that come with our higher level ECUs. The Link G4X AtomX ECU may be our entry level ECU but don't let its size fool you.