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Ignitions and Electrical› Computers, Chips, Modules and Programmers

MegaSquirt

Classic 3 ECU with MS3X Expansion

$799.99 $699.99 Save $100.00

SKU: MS3X357-C

Special Order
Special Order
Ships in 4–6 weeks
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Advanced — 4+ hours

Overview

The Classic MegaSquirt 3 ECU with MS3X Expansion is a powerful and flexible engine management solution for serious racers and custom builds. It offers advanced features such as sequential fuel and spark, boost control, 2-step launch, progressive nitrous, and onboard traction control.
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The Classic MegaSquirt 3 ECU with MS3X Expansion is a powerful and flexible engine management solution designed for serious racers and custom builds. It provides advanced capabilities that surpass earlier MS1 and MS2 systems, making it ideal for competitive drag cars, time attack machines, or high-performance street cars. This ECU features 8 sequential fuel injector outputs and 8 logic-level ignition outputs, supporting smart coils like LSx and IGN1A. It also includes 6 medium current outputs for functions such as boost control and fan control, 3 analog sensor inputs for external sensors like MAP and fuel pressure, and 4 switch inputs for features like launch control. For data management, it has a built-in USB port and an SD card socket for onboard logging (SD card sold separately). Key Features: - 8 sequential fuel injector outputs (high impedance) - 8 logic-level ignition outputs (requires coils with internal ignitors or external ignition module) - 6 medium current outputs (for boost control, fan control, etc.) - 3 analog sensor inputs - 4 switch inputs - 1 cam sync input (VR, Hall, or optical) - 16x16 VE and ignition tables with full interpolation - Built-in USB port and SD card socket - Closed loop idle and AFR control - Extensive OEM trigger pattern support Note: Requires external ignition drivers or smart coils. SD card and wiring harness are sold separately.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

BrandMegaSquirt
Part NumberMS3X357-C
CategoryIgnitions and Electrical
5,000+ Trusted brands
1M+ Enthusiasts
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(760) 282-4645 hello@motormia.co

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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

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