Mini MS3 90-97 1.6L & 94-95 1.8L

The Mini MS3 is the perfect budget option for your 90-97 1.6L / 94-95 1.8L Miata/MX-5!


If you are on a tight budget and don't need a lot if inputs and outputs, just an ECU that will run your N/A or turbocharged/supercharged Miata, look no further than the Mini MS3.

The Mini MS3 is designed to fit in the stock ECU's case, making mounting easy and clean.

The V3 Mini has sequential injection, sequential ignition (requires changing to individual coils and removing the igniter module), analog wideband input, flex fuel input, boost control output, VVT control output, launch/flatshift input, 1 spare digital input and 1 spare analog input.

Additional inputs can be added through the use of expanders as the Mini MS3 has support for CAN Bus 2.0A and 2.0B (11bit/29bit) at 500kBps.

This model (MMS390979495) will work on all 90-97 1.6L and 94-95 1.8L Miatas by setting the correct jumpers (see the above picture which shows the bottom side of the board with legend that explains how to set the jumpers.

The jumpers also allow you to upgrade your 90-93 Miata that comes with batch injection from the factory, to sequential injection by rewiring and changing the jumpers.

All Mini MS3s are equipped with a 4-bar onboard MAP sensor, this means you can run up to 3bar/43.5psi of boost - if you are brave enough to try that on a Miata!

V3 Minis support VW "R8" coils. Only the V3 Minis support them, V1 and V2 do NOT support the R8 coils.

The standard SD card slot allows you to datalog on a Class-4 SD card, up to 16GB. A few 32GB cards will also work but will not report correct size and therefor are NOT recommended.

Product Features

The Mini MS3 ECU for the 1.6L NA (MMS390979495) includes:

  • Batch fire and Sequential injection (selectable by jumpers)
  • Wasted spark or Sequential ignition (Coil On Plug, Coil near plug)
  • Advanced knock control with DSP and knock windowing
  • Standard idle control (stock 2-wire idle valve)
  • Tachometer output
  • Dual cooling fan output (Cooling fan with idle-up, condenser fan [if available])
  • Standard A/C control
  • Electronic boost control with 2 boost tables, boost by gear, boost by VSS
  • 1 digital (on/off) input (for switchable maps, launch control, datalog start/stop, boost high/low, etc), ground to activate.
  • 2 spare programmable outputs (On/Off or PWM)
  • 1 spare 0-5V analog input (with selectable 5V pullup)
  • Externally accessible SD Card slot
  • Internal MAP sensor for up to 43.5psi of boost
  • VVT Control
  • Flex Fuel sensor input
  • CAN Bus connectivity
  • USB port

The 90-97 model also includes:

  • High-side fuel pump or low-side fuel pump output (selectable by jumper).

Product Specifications

  • Operating voltage: 7.5-15.5V DC
  • Absolutely maximum voltage: 18V DC
  • Operating current: 120mA
  • Number of processors: 1
  • Processor type/speed: 16bit, 50MHz with XGate CoProcessor
  • Enclosure: None, ECU fits inside OEM case
  • Length: 154mm
  • Width: 110mm
  • Height: 32mm
  • Weight: 0.25kg
  • Color: Black
  • Operating temperature: -20°C to +100°C

Product Options

The Mini MS3 doesn't have any options.


This is a list of the most frequently asked questions we get. If you didn't find the answer you were looking for here, please contact us.

What is a standalone ECU?

A standalone ECU is a user-programmable ECU that fully replaces the OEM ECU. This is the opposite of a ‘piggyback ECU', which works in parallel with (and requires the use of) the stock ECU.

What is the benefit of installing a standalone ECU in my car? How many HP will I get?

A standalone ECU will not give your car ‘X' additional HP just by installing it. Think of the standalone ECU as a tool that will help you unleash the potential of your engine, with any modifications you may have installed (such as a turbocharger, supercharger, cams, intake filter, headers, exhaust, etc), by fine tuning the air/fuel ratio of the engine and adjusting the ignition timing so that peak torque can be achieved throughout the engine's rev band.

Is a standalone better than a piggyback ECU?

This widly depends on the use of the car and the modifications it actually has. A piggyback ECU is some times easier to tune if the mods are basic intake/exhaust mods. However, many times the changes are not consistent over time. For example, you may find that a tune that was done during the winter is no longer good during the summer and vice versa. Sometimes this may happen the following day or even on the next engine restart. This is because the piggyback ECU doesn't have all the facts and only coarsely changes the injection duration and the ignition timing. This becomes much more evident when replacing the OEM injectors with higher-flow aftermarket injectors.

So how does a standalone fare better than a piggyback?

The standalone has absolute control over all the sensors of the engine, as well as full control over the injectors and the ignition timing. This means that the ECU knows whether the climate is hot, warm, cold or freezing, it knows if the engine just started, if it is warming up or heatsoaked, it knows how much throttle you are applying and whether you are in boost or not, of if the engine is knocking. It then takes all these inputs and calculates the proper fuel injection duration and applies the proper ignition timing.

That sounds complicated. Do I need years of experience to actually even get the car to start?

No. Our plug and play ECUs come with detailed instructions for an easy install, and with basemaps so that you can get started immediately. There's no need to go looking on the Internet for maps to load; the ECU will come preloaded with one.