March 12, 2013
Contributers: MustangMan

DIY AutoTune's MS3-Pro Stand Alone Engine Management Officially Released

Check out the impressive details of the MS3-Pro below.

The new MS3-Pro standalone engine management system recently made its debut at the Performance Racing Industry trade show in Orlando, Florida, and is now available for order. This new system is based on the proven MegaSquirt-III design, but has revised it heavily to better meet the needs of professional tuners and racers.

"A lot of backyard tinkerers love that they can pick and choose what circuits to put in their original MegaSquirt so it has just what they need and nothing they don't, but most professional tuners don't want to order circuits on their ECU like toppings on a pizza," says Matt Cramer, engineer for "These are set up for shops where time is money, and where you want to stock a standard unit you can just keep on the shelf, and know it's going to meet the needs of just about anyone who walks in your door."

The MS3-Pro is ready to support a wide variety of engines out of the box, with the ability to run a V8 with sequential fuel and coil on plug, a V12 with sequential fuel and wasted spark ignition, or a four rotor Wankel with separate leading and trailing ignition outputs. Over 50 different ignition modes are supported, from mainstream applications like the GM LS1, Bosch Motronic, and Chrysler Gen III Hemis to unusual modes like Renix Jeeps and the Suzuki Swift GTI.

The MS3-Pro's packaging is also a departure from most previous MegaSquirt EFI Systems. Instead of the industrial looking split aluminum case and D-sub connectors, the MS3-Pro uses a sealed high temperature nylon case for light weight and compact size, and heavy duty AMPSEAL connectors. This provides a compact and sealed enclosure protecting the sensitive internals from the elements. The MS3-Pro's design keeps the heat generated to a minimum, allowing it to use a lighter plastic case instead of a metal heat sink. The MS3-Pro weighs about half as much as many competing ECUs.

Retail pricing is $1,199 with an 8-feet flying lead wiring harness.

Here is a complete list of the MS3-Pro's features:

Hardware features:

• Freescale MC9S12X 16 bit, 50 MHz asymmetrical dual core processor

• 10 saturated injector drivers • 8 logic level ignition outputs

• 3 high current (5 amp) general purpose outputs - 2 can be reconfigured as additional injector drivers

• 3 medium current (3 amp), high frequency general purpose outputs

• 1 stepper H-bridge driver

• Camshaft and crankshaft differential inputs - supports VR, Hall effect, and optical input

• 12 volt tach output • Fuel pump output

• 8 analog inputs (5 dedicated sensor inputs, 3 general purpose)

• 5 general purpose on/off or frequency inputs

• 2 digital I/O logic inputs

• 2 knock inputs

• RS232, USB 2.0, and CAN communication

• Onboard 8 gigabyte SD card for internal data logging

• Internal ECU temperature sensor

• Real time clock

• Temperature range: -30 to +80 degrees C (-40 to +85 without battery for real time clock)

Software features:

• Supports speed density, alpha-N, or MAF based fuel and spark tables

• Allows blending multiple load types, including a specialized mode for independent throttle bodies

• Auto-Tuning Capabilities using the 'VE Analyzer Live' feature of the included TunerStudio MS software and your wideband o2 sensor.

• 1 microsecond injector pulse width resolution

• Tables for nonlinear injector behavior at small pulse widths

• Supports a wide variety of OEM cam and crank position sensors and trigger wheels

• Individual cylinder trim tables for fuel and ignition

• Accelerator pump or model based acceleration enrichment

• Closed or open loop idle speed control

• Closed or open loop boost control with gear or speed based tuning options

• On/off or closed loop continuously variable valve timing control - supports up to 4 channels

• On/off or progressive nitrous control

• Traction control

• Rally anti-lag

• Rotary support - can run up to 4 rotor engines with separate leading and trailing spark tables

• Staged injection

• Table switching

• 16 x 16 fuel and spark tables - can be reconfigured to function as 30 x 16 or 16 x 30 by switching tables based on RPM or load

• 2 or 3 step rev limiter with no-lift shifting

• Wideband AFR target tables

• Flex fuel sensor input

• Allows repurposing injector or ignition outputs as general purpose outputs, or high current outputs as injector drivers for 12 cylinder sequential applications

• Real time barometric correction

• A/C and cooling fan control with idle compensation

• Safety shutdown based on AFR or EGT input

• Motorcycle shift cut

• 6 General purpose on/off or PWM/Frequency inputs

The MS3-Pro is a universal, ruggedized, wire-in ECU that is ready for serious duty in your motorsport of choice. Additionally, will follow up with several plug and play variations based off of the MS3 Pro architecture for 2013. Some of the planned plug and play systems include the C4 Corvette ZR1, Toyota Supra Twin Turbo, and 4.6L Mustangs. For more information on the MS3-Pro and other products, contact us at, or see the MS3-Pro website at

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