Welcome to ExtraEFI - with over 20 years supplying, modifying and providing technical support for all your MegaSquirt needs.
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MegaSquirt is an affordable, standalone, Mappable Engine Management System that can control the Fuel and Ignition on virtually any liquid fueled spark-ignition engine, naturally aspirated or boosted.

A MegaSquirt ECU can give you Mappable Ignition using:

and Mappable Fuel in these modes:

MegaSquirt ECUs are available:

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.

Are you still confused about MegaSquirt? Click here

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

Mappable Fuel table

16x16 fuel table for finer control

Mappable Spark table

12x12 spark table for accurate ignition control

Rev limiter

Cut fuel and or ignition

Overboost Protection

Protects your engine from overboosting and causing damage.

Air:Fuel Ratio Targets

Mappable Air-Fuel ratio targets for EGO correction.

Lambda Sensors

Wide Band (with controller) and Narrow Band

Coolant based Timing Advancement

Increase advance when the engine is cold

Air Temp based Timing Retard

Remove advance from table if Inlet Air gets hot

Closed Loop Ignition Idle

Use the ignition timing to stabilise idle speed

Closed Loop Idle Control

Control the idle valve to maintain target engine speeds

Acceleration Enrichment

Based on an adjustable blend of MAP / Throttle Position rate of change

Overrun fuel cut

Improve Fuel Economy by cutting fuel on overrun.

Hybrid Alpha-N

Use a combination/blend of the TPS & MAP sensors to calculate engine load.

Staged Injection

Use 2 banks of injectors at different positions in the inlet track.

Air Density Correction

Built in Air Density Correction

PWM Idle Control valves

Support for 2 and 3 wired PWM controlled valves.

Stepper Motor Idle Control Valves

Support for 4 wired stepper controlled valves.

Fuel & Ignition

Control Fuel and Ignition, Fuel Only or Ignition Only