TuneFI
A fuel controller for single-cylinder EFI bikes, tuned live from your phone. Reserve your unit with a $5 refundable deposit — it tells me how many to build and in what Lite/Full split.
Choose your version
TuneFI
$350Everything in Lite, plus 100+ Hz logging, wideband, ECU access, and ignition restore.
- +3D fuel mapping (RPM × TPS)
- +Android app — live tuning, map switching
- +Data logging · 100+ Hz (200 Hz bench-tested)
- +Wideband AFR — Spartan 3 or any 0-5V controller
- +ECU sensor access (K-line)
- +TPS spoof / ignition restore
$5 refundable deposit. Credited to your unit. Nothing ships now — first units are targeting September. When your version is ready I'll email the balance ($245 Lite / $345 Full) and arrange shipping. Fully refundable until you commit.
What It Is
TuneFI is a fuel controller for single-cylinder EFI bikes — the only one you tune live from your phone. It connects over Bluetooth and ships ready, with a plug-and-play harness into your bike's existing sockets. Open the app and tune: no laptop, no dyno, no special cable.
You don't need to know fuel mapping to use it. For common mods — exhaust, air filter, altitude — community maps are in the works: you'll be able to download a known-good baseline and ride, without tuning from scratch. Prefer to tune it yourself? Adjust the map live as you ride.
When you want more, the same device grows with you. Live 3D fuel-map editing (RPM against throttle position), high-rate data logging, direct access to your ECU's own sensors, optional wideband air-fuel readout, and over-the-air firmware updates that keep adding capability. Nothing to re-buy, nothing to learn all at once — you only use what you need.
It's real, shipped hardware — purpose-built electronics, with active development you can follow in the Discord. And once it's set, the bike runs on its own: the phone is only for tuning and logging, not for riding. Tune it from the Android app — on Google Play.
How Pre-orders Work
The $5 deposit reserves your version and is the demand signal for the production run. You are not buying a finished product today. When units are ready, I'll contact everyone on the list to collect the balance and ship. The deposit is fully refundable until you commit to the unit.
Specs
| MCU | ESP32-C6 (RISC-V) — injector and voltage handled deterministically by hardware (MCPWM, ADC via DMA). No BLE contention. |
| INJECTOR | VNLD5160 automotive-grade driver |
| CONTROL | Alpha-N, 16 × 16 fuel map (RPM × TPS) |
| LOGGING | 100+ Hz (up to 200 Hz bench-tested): RPM, TPS, injector pulse width, AFR |
| ECU | K-line — RPM, TPS, temps, manifold pressure, speed, FI codes |
| COMMS | Bluetooth Low Energy |
| FIRMWARE | ~30,000 lines of C, ~92% test coverage; OTA updates |
| ENCLOSURE | Waterproof aluminum, sealed cable glands |
| BIKES | Any single-cylinder EFI bike (developed on a KLX250/300, incl. a 355 big-bore) |
Wideband AFR
Optional, and sold separately — it's for riders who want to dive deep and fine-tune the map to their exact setup, fuel, and conditions. TuneFI runs fully without one; add it only if you want to measure real air-fuel ratio and dial in every cell.
TuneFI reads a Spartan 3 over UART, or any wideband controller that outputs a linear 0–5V signal (two-point calibration in the app) — whatever you already own should work.
Recommended: the Spartan 3 V2 Lite bundled with the LSU 4.9 sensor (~$135) — much better value. On a tight budget, the SLC2 Free is $45.
More
Full development story, signal path, and timeline on the TuneFI project page. Watch the full V2 walkthrough — board, app demo, and live ECU data — on YouTube. Questions or want to follow along? Discord.