DIY AutoTune MegaSquirt Engine Management Systems Now Available at Summit Racing

Setting up and tuning an EFI engine for ludicrous power used to be something best left to a dedicated tuning shop. They handled the wiring and programming and tuning—and charged you a pretty penny to do so.

And that is still a valid way to set up and tune a serious EFI engine. But thanks to DIY AutoTune, there is an alternative. The company makes programmable engine management systems based on the tried-and-true MegaSquirt architecture that gives you the tools needed to dial in your engine for maximum power and performance. If you have the patience and willingness to learn, you can do the tuning you used to pay someone else to do for you.

Summit Racing offers DIY AutoTune plug-and-play and standalone engine management systems:

MegaSquirt Plug-And-Play Systems
DIY AutoTune plug-and-play engine management systems are standalone units that are direct-fit replacements for the factory ECU. They have a pre-loaded base map that will let you fire the engine and start tuning; if you run into issues, you can always revert to that baseline tune.

The ECUs plug into the factory wiring and take about an hour to install. Basic features include:

• Real time tuning and data logging with a laptop connection
• 16x16 fuel tables allow high resolution tuning
• 12x12 air/fuel ratio target tables for precise tuning with wideband O2 sensor
• Table switching input—change fuel and spark maps on the fly for different fuels, nitrous activation, etc.
• Multiple acceleration enrichment strategies
• Closed loop idle speed and air conditioner controls
• Onboard peak and hold drivers support both high and low impedance injectors
• Allows removal of stock airflow meter or stock MAF sensor if so equipped
• Real time barometric correction
• Internal 4-bar MAP sensor reads up to 44 psi of boost
• Overboost protection
• Closed loop boost control (requires boost solenoid kit, sold separately)
• Knock sensor input with adjustable sensitivity, crank angle windowing, and more 
• Input for flex fuel sensor—switch between E85 and gasoline on the fly
• CAN Bus connector works with MegaSquirt-compatible devices to add functions like EGT input, automatic transmission controller, and additional sensors
• Supports most aftermarket wideband sensors
• Tuning software and documentation USB stick included

The MegaSquirt Gen2 ECUs have 12x12 ignition tables, a built-in two-step rev limiter/launch control, and a knock sensor headphone output to listen for knock while you tune. They are available for Mazda Miata; Fox-body and SN95 Mustang 5.0L; BMW E30/32/34; Toyota MR2/AE86 Corolla; and Nissan 240SX.

The MS3Pro ECUs have 16x16 ignition tables; three-step rev limiter/launch control; sequential fuel injector channels with individual trim tables; multiple traction control strategies; water injection control; 8 GB internal data logging with built-in SD card; and a registered version of TunerStudio and MegaLog viewer. The ECUs are available for Mazda Miata; BMW E36; Subaru Impreza/WRX; and Toyota Supra/Lexus SC300.

MegaSquirt MS3Pro Standalone Systems for GM LS Engines
Now you can dump a GM LS engine into anything with wheels and have the ability to tune it properly. The list of features is as long as a Funny Car burnout—here are some of the major ones:
• VE-based tuning 
• Speed density, Alpha-N, MAF-based tuning and blended algorithms 
• Individual cylinder fuel and spark trim tables 
• Up to 12 sequential saturated fuel injector outputs
• Up to 12 cylinder sequential support
• High-speed data logging with internal SD card
• Generic wheel decoder supports nearly any standard trigger/aftermarket trigger pattern
• Supports 50+ OEM and aftermarket ignition systems using factory cam/crank wheels and sensors 
• Fuel-only mode disables ignition output features for control of fuel injection only
• Four-channel VVT control
• Multiple traction control strategies 
• E85 flex fuel sensor input 
• Multiple acceleration enrichment and nitrous control strategies 
• 3-step rev limiter with flat shift 
• Trans-brake and bump box control
• Advanced launch control strategies
• Rally-style turbo anti-lag with rotational idle
• Boost and idle control with multiple open and closed loop strategies 
• Water and methanol injection controls
• Fuel pump control 
• Two-channel intelligent knock detection and response
• Air conditioner control with feed-forward idle-up
• Cooling fan control with programmable fan-on and -off activation points
• CAN Bus support for I/O expansion and third party dash devices 

The MS3Pro EVO systems’ ECU has 10 high-impedance injector outputs; eight logic level spark outputs; three PWM outputs; two digital outputs; seven analog inputs, three high-current digital/PWM outputs; three digital frequency inputs; and built-in MAP, barometric pressure, and internal ECU temperature sensors.

The MS3 Ultimate systems’ ECU has most of the same features as the EVO unit, but comes with 10-channel 4:1 or 8:2 programmable peak and hold injector outputs; six digital inputs; 12 analog inputs; and five PWM outputs.

Going with a MegaSquirt ECU or standalone engine management system is a big step. That’s why we suggest reading up on how they work and what it takes to install and use one. A good place to start is the FAQ section of the DIY AutoTune website, which has a ton of great information and links to more in-depth reference articles. And the company offers lifetime support for its systems, which should give you some peace of mind if you run into issues.

SEE DIY AUTOTUNE MEGASQUIRT ENGINE MANAGEMENT SYSTEMS AT SUMMIT RACING