https://github.com/rusefi/hellen-NB1-issues

[Miata 1999](Mazda-Miata-1999)

[[ibom rev a]](https://rusefi.com/docs/ibom/hellen64_NB1-a-ibom.html)

[neomiata 2000 Wiring Diagram](http://neomiata.com/garage/Wiring%20Diagrams/Wiring%20Diagrams%201997-2000/2000_Miata%20Wiring%20Diagrams.pdf)

[Schematic Rev A](Hardware/Hellen/hellen64_NB1-a-schematic.pdf)


## Options Port (rev. b)

| Pin | Type | Comments |
|---|---|---|
| 4A | Ground | |
| 4B | Digital Input | Flex Sensor |
| 4C | Temperature or PPS2 | Temp or ETB Pedal |
| 4D | Boost Controller Output |
| 4E | VVT Output | |
| 4F | +5v |
| 4G | WBO Vs/Ip | LSU 4.9 Pin 2 |
| 4H | WBO Vs | LSU 4.9 Pin 6 |
| 4I | WBO R Trim | LSU 4.9 Pin 5 |
| 4J | WBO Ip | LSU 4.9 Pin 1 |
| 4K | WBO Heater - | LSU 4.9 Pin 3 |
| 4L | +12v | LSU 4.9 Pin 4 |


**Options Port Schematic**

![x](Hardware/Hellen/H76a-Options.jpg)

## Additional Hardware

[Options Port Connector](https://www.bmotorsports.com/shop/product_info.php/products_id/3460?osCsid=ru4mqe3g51skdvoflufkdpao00)

[LSU 4.9 Wideband Connector](https://www.bmotorsports.com/shop/product_info.php/products_id/2081)

[LSU 4.9 Wideband Sensor](https://www.bmotorsports.com/shop/product_info.php/products_id/1645) Or Similar