Getting started
Every rusEFI ECU runs the same open-source firmware. Sequential injection and ignition, wideband, knock, drive-by-wire, boost, launch, flex fuel, Lua, CAN — all of it comes with the firmware. You choose a board by how much engine you attach and what package you need.
1. Which board
| Your engine | Board | On the board | Connector, case | From |
|---|---|---|---|---|
| 1–2 cylinders, or a simple batch-fire 4. Bikes, karts, small engines | nano | SD logging, CAN. No wideband, no knock. Inductive ignition only, not CDI | Superseal 26 pin, no case | $225 |
| 1–6 cylinders, port injection. Most swaps and track cars | uaEFI | Wideband, knock, baro, dual drive-by-wire, SD logging | Molex plugs, optional plastic case | $275 |
| Same engines, ECU lives somewhere hot or dirty, one plug | uaEFI 121 | As uaEFI, dual wideband | TE 121 pin, metal case | $375 |
| Same engines, motorsport harness, big Lua scripts | super-uaEFI | As uaEFI 121, faster chip, removable SD card | Superseal 120 pin | $410 |
| 8–12 cylinders, or many actuators (dual throttle + wastegates) | rusEFI Huge | 12 injectors, 12 coils, dual wideband, dual knock, 4 H-bridges | Superseal 120 pin | $850 |
| 4-cylinder gasoline direct injection | Power4GDI | GDI injector drivers, wideband, knock | Superseal 68 pin | $1,050 |
Also in the store: Proteus ($800, 12 cylinders, IP68 waterproof case, wideband not on the board) and microRusEFI ($475, 4 cylinders). Both are older designs; for a new build pick from the table.
Plug-and-play boards for Honda OBD1, Honda K and GM LS fit the stock harness — see Plug and Play.
Not sure? Post your engine on the forum or Discord before you order.
2. Side by side
| nano | uaEFI | uaEFI 121 | super-uaEFI | Huge | Power4GDI | |
|---|---|---|---|---|---|---|
| Max engine | 1–2 cyl, 4 cyl batch | 1–6 cyl | 6 cyl, 8 cyl wasted spark | 6 cyl, 8 cyl wasted spark | 12 cyl | 4 cyl GDI |
| Injector channels | via 6 low-side | 6 sequential, up to 8 | 6 sequential, up to 8 | 6 sequential, up to 8 | 12 | 4 GDI |
| Ignition | smart or dumb coils | 6, smart coils; igniters can be added | smart coils; igniters can be added | smart coils; igniters can be added | 12 logic level | 4 |
| Trigger inputs (VR + Hall) | 1 VR | 2 + 3 | 2 + 3 | 2 + 3 | 3 + 5 | Hall only, 1 |
| Analog inputs | 5 | 9 + 2 | 7 + 2 | 7 + 2 | 13 + 2 temp | 6 |
| Knock | — | yes | yes | yes | dual channel | yes |
| Wideband controller | — | LSU 4.9 | dual LSU 4.9 | dual LSU 4.9 | dual LSU 4.9 | LSU 4.9 |
| Barometric sensor | — | yes | yes | yes | yes | — |
| MAP sensor | — | solder-on | solder-on | solder-on | solder-on | solder-on |
| Drive-by-wire | — | dual | dual | dual | 4 H-bridges | single |
| SD card logging | yes | yes | yes, fixed card | yes, removable card | yes | yes |
| CAN bus | 1 | 1 (2 on PRO) | 1 | 1 | 2 | 1 |
| Connector | Superseal 26 | Molex Mini-Fit Jr., 5 plugs | TE 121 pin | Superseal 120 pin | Superseal 120 pin | Superseal 68 pin |
| Enclosure | — | optional plastic | metal | optional plastic | — | — |
| Hardware files | — | schematics, PCB, gerbers | — | schematic PDF | schematic PDF, iBOM | schematic PDF |
| Price from | $225 | $275 | $375 | $410 | $850 | $1,050 |
3. Configure your order
uaEFI has four options. The other boards have fewer; the product page shows them.
| Option | Choices | Price | Pick |
|---|---|---|---|
| Version | normal · PRO | PRO +$24 | Normal. PRO adds a faster chip, memory for large Lua scripts, a second CAN bus and a knock spectrogram. Most builds do not need it |
| Board | Molex soldered · no Molex | same price | Molex soldered. "No Molex" only if you will solder wires straight to the board |
| Enclosure | none · orange plastic | +$50 | Enclosure, unless the board goes into a factory ECU case |
| Harness side | nothing · crimp kit · pigtails + wideband cable | +$0 · +$35 · +$100 | Crimp kit if you have a Mini-Fit Jr. crimp tool; pigtails (pre-crimped wires you splice into your harness) if you don't |
A typical first order: normal, Molex soldered, enclosure, pigtails — $425.
4. What else you need
- A MAP sensor: external, or solder one onto the board.
- A Bosch LSU 4.9 wideband sensor for the on-board controller (not in the box).
- Harness wire, terminals and a crimp tool.
- A Windows, Mac or Linux laptop with USB. Tuning software is TunerStudio (third-party, paid).
- Your sensors, coils and injectors, as with any standalone.
5. When it arrives
- Download the firmware bundle for your board: Downloads.
- Install TunerStudio and open the project from the bundle: How to create a TunerStudio project.
- Wire the ECU from the interactive pinout linked on the product page.
- First start: Quick Start. Questions go to the forum or Discord; post your tune and logs.
Paid one-on-one help: Technical Support.
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