The Frankenso board was designed to be used on Mazda Miata NA6 as a plug-and-play solution.

Stage 0

Everything stock running rusEFI ECU

All stock sensors, no extra wires, no extra hoses - just lift the carpet and plug rusEFI box instead of OEM ECU.

Timing, fuel control based on VAF/MAF, programmable check engine light, A/C compressor control. Online tuning using TunerStudio.

SD card logging, LCD screen and joystick because why not.

Stage 1

Stage 0 + External wide band controller, wide band oxygen sensor, external MAP sensor

Stage 2

Stage 1 + TPS

Bench testing options

On NA6 Spark #1 and Spark #3 would audibly click if you use bench Spark Test button. Because of wasted spark wiring Spark #2 and Spark #4 are not expected to click.

On NA6 Injector #1 and Injector #2 would audibly click if you use bench Injector Test button. Because of batch injection wiring Injectors #3 and #4 are not expected to click.

All you need is a relatively quiet surroundings and you would hear both spark and injectors. Injectors are louder, spark is less loud but also totally audible. Both Test buttons are expected to produce three clicks a second after you press the button in the software.

Wideband O2 sensor wire WBO

You would really need a wideband sensor. Here is the middle plug pinout to wire an external wideband controller - +12v would feed external controller and analog output signal would provide rusEFI ECU with air/fuel ratio information.

middle plug

A small flat screw driver and small pliers allow you to move side latches and open the cap. Insert supplied extra pin wire (pin on this picture) and close the latches. Done!

extra wire


Frankenso Miata NA6 PNP Technical Details

TPS mod

Cars with automatic OEM engine harness use a better OEM TPS sensor. On vehicles with manual OEM engine harness this TPS mod is recommended.

original manual wiring:

3C/3D GND 1N - Red - ?? switch. ground if IDLE, floating if pressed/depressed 3L - Light Green / white ?? switch - ground if WOT, floating if not WOT

GND is middle pin on OEM manual plug unfortunately

stop light switch: ground if not depressed floating if pressed / depressed


Fly back diode: NSR0530HT SOD-323 SMD Schottky Barrier Diodes 30V 500mA 0.5A

Engine Wiring

Mazda_Miata_1990

Mazda_Miata_1994

Frankenso board

1996+ is too different unfortunately

Mazda_Miata_1996