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Ignitions and Electrical› Computers, Chips, Modules and Programmers

DIYAutoTune

MegaSquirt 3 ECU with MS3X Expansion

$799.99 $699.99 Save $100.00

SKU: MS3X357-C

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Ships in 4–6 weeks
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$100 Minimum Order
30 Days Return
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Overview

The DIYAutoTune MS3X357-C is an engine management system featuring the MegaSquirt 3 ECU with an MS3X expansion module. This system offers 8 sequential fuel injector outputs and 8 logic-level ignition outputs. It also includes 6 medium-current outputs, 3 analog sensor inputs, 4 switch inputs, and 1 cam sensor input, making it a versatile programmable engine control unit.
Show original supplier description
The DIYAutoTune MS3X357-C is a standalone engine management system designed for precise fuel control. This MegaSquirt 3 ECU comes with the MS3X expansion module, offering advanced features that surpass older MS2 and MS1 systems. Key capabilities include sequential fuel and spark control, a 2-step rev limiter, progressive nitrous injection, and boost control. This ECU boasts a 16x16 VE and ignition table resolution with full interpolation, ensuring smooth transitions and accurate tuning. It provides 0.1% fuel step resolution and 0.1° ignition accuracy for fine-tuned engine management. Connectivity is streamlined with a built-in USB port for easy laptop integration, and data logging is supported via an SD card. The system offers 8 sequential fuel injector outputs, compatible with LSx coils, IGN1A, and other smart coils, alongside 8 logic level 5-volt ignition outputs and 6 medium current outputs. Input capabilities include 3 analog sensors and 4 switch inputs, plus a dedicated cam sensor input.

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

BrandDIYAutoTune
Part NumberMS3X357-C
CategoryIgnitions and Electrical
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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.

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