Welcome to the ExtraEFI website!


I have been building MegaSquirt ECU's since 2003 and I'm one of the team who wrote the MS-Extra Code.

So you can rest assured this is THE place to purchase your MS ECU, with the knowledge that you will be getting what you need, rather than what someone wants to sell you.

No other MegaSquirt sales website comes close to this one for information, knowledge and backup of MS ECUs!

Everything you need to know is on this site, that includes video help files | ! If you still have any questions then I can answer them due to my experience with the actual firmware the ECU's run and with the years of experience I have building, tuning and testing them!

ExtraEFI was setup in 2005 with a simple aim; to supply fully assembled, tested and warranted MegaSquirt ECU's to a very high standard.

All my ECUs run the latest version of the MS Extra code. Well, they would do, as I'm one of the authors of the MS-Extra code and author of the MS1-Extra and MS2-Extra manuals.

MegaSquirt is a standalone DIY mappable Engine Management System that can control the fuel and spark or fuel only or spark only on virtually any liquid fueled spark-ignition engine, naturally aspirated or boosted.

Are you still confused about MegaSquirt? Click here

A MegaSquirt ECU can give you mappable fuel and or mappable ignition using:

All of the ECU's I sell have the MS-Extra code loaded into them, these are the features that come as standard:

16x16 Fuel table

Large 16x16 fuel table for finer control

12x12 Spark table

Large 12x12 spark table for accurate ignition control

Rev limiter

Limit and protect your engine

Overboost protection

Protects your engine from overboosting and causing damage.

Ratio Targets

Mappable Air-Fuel ratio targets.

Oxygen Sensors

Wide Band and Narrow Band

Ignition Timing Advancement

Based on your vehicles Coolant temperature

Ignition Timing Retard

Based on the Inlet Air temperature

Acceleration Enrichment

Based on Manifold Absolute Pressure rate of change or Throttle Position Sensor rate of change

Overrun fuel cut

Improve Fuel Economy by restricting fuel when not neccesary.

Hybrid Alpha-N

Use a combination of the TPS and MAP sensors to calculate fuel.

Staged Injection

Optimise your injection setup.

Air Density Correction

Built in Air Density Correction

PWM Idle Control valves

Support for PWM controlled valves.

Stepper Motor Idle Control Valves

Support for stepper controlled valves.

Fuel & Ignition

Fuel and Ignition, Fuel Only or Ignition Only