Classic MegaSquirt 3 ECU with MS3X Expansion

For the next-gen MS3Pro Universal ECU lineup - CLICK HERE The Classic MegaSquirt 3 with MS3X Expansion delivers a powerful and flexible engine management solution for serious racers and custom builds—offering advanced features that go far beyond earlier MS1 and MS2 systems. With capabilities like sequential fuel and spark, boost control, 2-step launch, progressive nitrous, and onboard traction control, MS3X gives you race-ready performance at an accessible price. Whether you're building a competitive drag car, time attack machine, or high-performance street car, MS3X gives you full control and room to grow. Ideal For: Budget-conscious racers looking for pro-level features Custom EFI conversions needing full sequential control Builders upgrading from MS1, MS2, or other entry-level ECUs Note: Requires external ignition drivers or smart coils. SD card and wiring harness sold separately. Key Features: 8 sequential fuel injector outputs – Each drives a high impedance injector – Unused outputs can be repurposed for other controls 8 logic-level ignition outputs – Supports LSx coils, IGN1A, and other smart coils – Requires coils with internal ignitors or external ignition module 6 medium current outputs – Ideal for boost control, progressive nitrous, fan control, 3-wire idle, tach, or relay outputs 3 analog sensor inputs – Connect external MAP, second O2, fuel pressure, accelerometer, etc. 4 switch inputs – Use for table switching, nitrous arming, launch control, VSS input, and more 1 cam sync input – Compatible with VR, Hall, or optical cam sensors Tuning resolution – 16x16 VE and ignition tables with full interpolation – 0.1% fuel step resolution, 0.1° ignition accuracy Data Logging & Connectivity – Built-in USB port – SD card socket for onboard logging (SD card not included) – CANBus support for expansion modules Idle & Mixture Control – GM stepper IAC supported – Closed loop idle and AFR control Extensive OEM trigger pattern support – Native decoding for many OEM crank/cam signals – Ideal for retrofit or fully custom engine management setups