The ULTIMATE GUIDE To Installing An NB Cluster Into An NA Miata!

Below you will find the links to every resource I used to compile this video, as well as the important parts and tools you may need to do something similar! I drew several different wiring diagrams based on the possible equipment in your car, and while I do my best to get everything perfect, some things are outlined below that I have not personally tested. Please let me know if you find any mistakes and I will get them fixed! Cheers


Re-Pinning The NA Harness into the NB Plugs

This is a diagram of the exact setup of the plugs in my car. It’s a 1992 chassis, manual transmission, with no cruise control or ABS. This pinout should be the same or nearly identical for 1990-1997 cars.


Vehicle Speed Sensor Setups & Speedometer Wiring

A couple notes here: While using the front wheels for vehicle speed sensing is technically more accurate as it factors out wheelspin, it’s not the correct way to link into a standalone ECU’s “Gear Detection” which is used for boost-by-gear, digital gear indicators, or when datalogging gear changes; as wheelspin will throw off its calculation. Also, in order to set up traction control, you will need a front and rear speed sensor. This type of traction control compares the front and rear wheel speed, and if the rear is rotating faster than the front the ECU can be tuned to limit power. You can add a front wheel sensor using a front ABS ring or hall effect sensor that monitors the back of the wheel studs passing it (Thanks to dctmiata for that pro tip.)





Megasquirt Settings

These are my current exact settings in my 90-93 MSPnPPro, for the way my speed sensor is set up in the video. The speed reading in the ECU still needs minor calibration, but that’s as simple as changing the PPM. (i.e. Might need to be 47,600 instead of 48,000). At first my gear indicator would not pick up the correct gear all the time, that was fixed by changing the tire diameter field. A tire size calculator spit out 22.7″ for my 245/40R15’s, but as seen here it needed to be set at 22.0″. Ah, tuning!

Parts

NB Clusters From Treasure Coast: 99-00 | 01-05

Dakota Digital SGI-5 E

-Note: As of writing this, the SGI-5E is out of stock everywhere. You may be able to get it directly from Dakota Digital. You can also use the SGI-100BT which is a combination speedo/tach conversion box for around the same price. Wiring should be identical.

Revlimiter Gauge Faces (Also: How To Install Revlimiter Gauge Faces)

Hall Effect Sensor

Motion Raceworks Trigger Wheel (Get the right size for your application!)


Outside Resources

Diagrams From Google & Threads Linked Below

Scenturion’s NA Oil Pressure Gauge Retrofit

Scenturion’s NB Cluster Speedometer Analysis

Chelsz H NB Cluster Swap Video

Lance Schall’s NB Cluster Swap Thread

Tire Rotation/Mile Calculator