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M-Engineering ECU Tune McLaren M838T

Price
$3,995.00
Currently Backordered - You can still place your order and we'll ship your order as soon as the product is back in stock!

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Installation Services

Don’t worry about the hassle — let our expert team at Forza Motorworks handle the installation for you. Our professional installation ensures everything fits and operates exactly as intended, giving you clean, factory-quality results, proper wiring or mounting, and avoiding the risks of DIY mistakes. You’ll save time, avoid frustration, and get peace of mind knowing the job is done right the first time. Contact us to learn about our installation services and enjoy a seamless upgrade from day one.

FAQ

Shipping Information
For items that are in stock, purchases made after 9am EST will be usually be shipped out in the next 1-2 business days. Please inquire to confirm lead times if you have specific time constraints. Orders will be sent via signature required at our discretion unless otherwise requested. 

International Shipping
Any and all customs duties, taxes, import fees, and/or tariffs assessed in connection with the purchase shall be the sole responsibility of the customer/end user.

Cancellations / Returns

Original sales receipt or order number must accompany all return requests.

Forza Motor Works accepts returns for exchange, store credit, or refund within fourteen (14) calendar days of the delivery date, subject to the terms and conditions below. After fourteen (14) calendar days, all sales are final unless otherwise approved in writing by Forza Motor Works.

To be eligible for return, products must be in new, unused, unaltered, and resalable condition, including all original packaging, instructions, hardware, documentation, and accessories. Returned items must not show any signs of installation, use, wear, damage, modification, painting, coating, or alteration of any kind.

The following items are non-returnable and non-refundable:

• Special-order products
• Custom-built or made-to-order products
• Products manufactured to customer specifications
• Custom color or finish products
• Manufacturer-direct-shipped products designated as non-returnable
• Products with extended lead times, including but not limited to headers, exhaust systems, wheels, and other special-order performance products
• Any item specifically identified on the product page as non-returnable

Orders for special-order, custom-built, made-to-order, vehicle-specific, or manufacturer-direct-shipped products may not be canceled once the order has been submitted to the manufacturer.

If an item is received damaged during shipping or was shipped incorrectly by Forza Motor Works, Customer Support must be contacted within forty-eight (48) hours of delivery. Claims for shipping damage must include clear photographs of the product, packaging, shipping box, and shipping label at the time of unpacking.

Products determined by Forza Motor Works to have been incorrectly shipped may qualify for replacement, store credit, or refund at our sole discretion. Manufacturer defects are subject to the applicable manufacturer's warranty policies and procedures. Forza Motor Works does not provide any separate product warranty unless expressly stated in writing.

All returns must be authorized prior to shipment and must be assigned a Return Merchandise Authorization (RMA) number. The RMA number must be clearly displayed on the outside of the return package. Returns received without an authorized RMA number may be refused or denied credit.

To obtain a Return Merchandise Authorization (RMA), please contact:

Forza Motor Works
Email: info@forzamotorworks.com

All refunds, exchanges, and store credits are contingent upon inspection and approval of the returned merchandise. Forza Motor Works reserves the right to deny any return that does not comply with this policy.

Approved returns may be subject to a restocking fee of up to twenty five percent (25%) of the purchase price. Original shipping charges are non-refundable. Customer is responsible for all return shipping costs unless the return is the direct result of an error made by Forza Motor Works.

FITMENT, INSTALLATION & PRODUCT USE

Customer is responsible for verifying vehicle compatibility, fitment, and intended use prior to installation. While Forza Motor Works makes reasonable efforts to provide accurate product information and fitment guidance, final responsibility for compatibility rests solely with the customer.

Products that have been installed, test-fitted, modified, painted, coated, damaged, or otherwise used are not eligible for return.

Many aftermarket performance products are intended for off-road, racing, or competition use only and may not be legal for use on public roads in all jurisdictions. Customer is solely responsible for determining compliance with all applicable federal, state, and local laws and regulations.

LIMITATION OF LIABILITY

FORZA MOTOR WORKS SHALL NOT BE LIABLE FOR ANY INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, PUNITIVE, OR CONSEQUENTIAL DAMAGES ARISING FROM THE PURCHASE, INSTALLATION, USE, MISUSE, FAILURE, OR INABILITY TO USE ANY PRODUCT SOLD BY FORZA MOTOR WORKS.

FORZA MOTOR WORKS SHALL NOT BE RESPONSIBLE FOR LOSS OF TIME, LOSS OF REVENUE, LOSS OF PROFITS, LOSS OF VEHICLE USE, TOWING CHARGES, RENTAL VEHICLE COSTS, STORAGE FEES, DIAGNOSTIC FEES, INSTALLATION COSTS, REMOVAL COSTS, ALIGNMENT CHARGES, TUNING FEES, SHIPPING EXPENSES, FINES, PENALTIES, PROPERTY DAMAGE, VEHICLE DAMAGE, OR ANY OTHER INCIDENTAL OR CONSEQUENTIAL LOSS OR EXPENSE.

TO THE MAXIMUM EXTENT PERMITTED BY LAW, FORZA MOTOR WORKS' TOTAL LIABILITY FOR ANY CLAIM ARISING FROM THE PURCHASE OR USE OF A PRODUCT SHALL NOT EXCEED THE AMOUNT PAID FOR THE SPECIFIC PRODUCT GIVING RISE TO THE CLAIM.

By placing an order with Forza Motor Works, the customer acknowledges and agrees to all terms and conditions contained herein, including all return, exchange, warranty, and limitation-of-liability provisions.

Product Description

Unlock additional performance and take greater control of your McLaren with the M-Engineering M-Tuner Live Map Switching Calibration Suite. Developed specifically for McLaren vehicles equipped with the 3.8L twin-turbocharged M838T V8 engine, this advanced ECU tuning system combines performance software, wireless OBD flashing, real-time datalogging, and customizable engine management features in one comprehensive package.

Unlike conventional ECU tuning solutions that require the ECU to be shipped out for every calibration update, the M-Tuner v3 features wireless OBD flashing technology, allowing owners to install compatible M-Engineering calibrations directly through the vehicle's diagnostic port. Following a required one-time ECU bench procedure, customers can manage supported tuning updates and switch between available performance calibrations without repeatedly removing the ECU.

The M-Tuner Calibration Suite includes Stage 1 and Stage 2 performance calibrations, developed for different vehicle configurations and supporting modifications. M-Engineering also supports Stage 2+ applications, with appropriate additional hardware and calibration requirements. Original purchasers can update between eligible off-the-shelf tuning stages without additional calibration charges.

One of the system's most valuable features is Live Map Switching, which allows drivers to change between four preset calibration maps using the factory cruise control controls. The standard configuration includes dedicated maps for 91-octane, 93-octane, and 100+ octane fuel, along with a Valet Mode designed to limit engine boost, load, and throttle response.

Beyond performance tuning, the M-Tuner provides a comprehensive collection of vehicle management functions, including high-speed datalogging, live engine data monitoring, fault-code clearing, and dyno mode control. These features allow owners and technicians to monitor vehicle operation, review performance data, and manage supported ECU functions.

Additional calibration features include automatic start/stop disable, left-foot braking support, kickdown disable, and Loud Start functionality. These software options provide greater flexibility in how the McLaren behaves during everyday driving and performance-oriented use.

For owners with upgraded turbochargers, fuel systems, or other significant modifications, M-Engineering offers optional remote ProTuning and custom calibration services. These services allow the ECU calibration to be tailored to specific hardware configurations and fuel requirements beyond the standard off-the-shelf maps.

The M-Tuner system requires an initial one-time ECU bench procedure performed by M-Engineering. Once this process is complete, the ECU is returned to the customer for reinstallation, and the included wireless flashing device can be used for subsequent supported calibration updates.

For McLaren owners seeking improved performance, flexible fuel-specific calibrations, and convenient access to advanced ECU features, the M-Engineering M-Tuner Calibration Suite delivers a comprehensive tuning solution designed around the M838T engine platform.

Fitment Notes

  • Fits compatible McLaren MP4-12C / 12C models with the 3.8L twin-turbocharged V8

  • Fits compatible McLaren 650S Coupe / Spider models

  • Fits compatible McLaren 675LT Coupe / Spider models

  • Fits compatible McLaren 570S Coupe / Spider models

  • Fits compatible McLaren 570GT models

  • Fits compatible McLaren 600LT Coupe / Spider models

  • Manufacturer also lists support for the McLaren 625C, 620R, and 540C, with calibration availability requiring confirmation

  • Designed specifically for the 3.8L twin-turbocharged M838T V8 engine

  • Not compatible with McLaren vehicles equipped with the 4.0L M840T engine, including the 720S, 750S, and 765LT

  • Stage 1 and Stage 2 calibrations are available for compatible vehicle configurations

  • Stage 2+ support may require additional fuel system components or other supporting hardware

  • One-time ECU removal and bench procedure required before wireless OBD flashing

  • ECU must be shipped to M-Engineering for initial programming

  • Subsequent supported calibration changes can be performed through the M-Tuner device

  • Standard Live Map Switching includes 91, 93, 100+ octane, and Valet calibration slots

  • Fuel-specific maps must only be used with the appropriate fuel

  • Custom map configurations and ProTuning are available separately

  • Vehicle-specific calibration availability should be confirmed before ordering

  • Professional ECU removal and reinstallation recommended

  • ECU tuning may affect emissions compliance and factory warranty coverage

Included

  • M-Engineering M-Tuner v3 wireless OBD flashing dongle

  • M-Engineering ECU performance calibrations for the selected M838T application

  • Stage 1 and Stage 2 off-the-shelf calibration support

  • Live Map Switching functionality

  • Four standard calibration map slots

  • High-speed datalogging functionality

  • Live engine data monitoring

  • Fault-code clearing functionality

  • Dyno Mode enable/disable

  • Automatic start/stop disable functionality

  • Left-foot braking support

  • Kickdown disable functionality

  • Loud Start functionality

  • One-time ECU bench programming service

  • M-Engineering technical support

Sold Separately:

  • ECU removal and reinstallation labor

  • ECU shipping and insurance

  • M-Engineering M838T Motorsport Tuning Package

  • M-Engineering remote ProTuning and custom calibrations

  • Stage 2+ supporting hardware, where required

  • Additional performance exhaust, intake, or turbocharger components

Product Specs

  • Manufacturer: M-Engineering

  • Product Name: M-Tuner Live Map Switching Calibration Suite

  • Product Type: ECU Tuning & Wireless Flashing System

  • Engine Platform: McLaren M838T

  • Engine Configuration: 3.8L Twin-Turbocharged V8

  • Supported Models: 12C, 650S, 675LT, 570S, 570GT, 600LT & Select Additional M838T Applications

  • Flashing Device: M-Tuner v3

  • Flashing Method: Wireless OBD

  • Initial ECU Bench Procedure: Required

  • Live Map Switching: Included

  • Map Switching Controls: Factory Vehicle Controls

  • Standard Map Quantity: 4

  • Map Slot 1: 91 Octane

  • Map Slot 2: 93 Octane

  • Map Slot 3: 100+ Octane

  • Map Slot 4: Valet Mode

  • Off-the-Shelf Calibration Stages: Stage 1 / Stage 2

  • Stage 2+ Calibration Support: Available with Appropriate Hardware

  • Datalogging: Included

  • Live Data Monitoring: Included

  • Fault-Code Clearing: Included

  • Dyno Mode Control: Included

  • Automatic Start/Stop Disable: Included

  • Left-Foot Braking: Supported

  • Kickdown Disable: Included

  • Loud Start: Included

  • Custom Calibration Support: Available Separately

  • Motorsport Feature Expansion: Available Separately

  • Typical ECU Bench Turnaround: Approximately 24 Hours After Receipt

  • Manufacturer Support: Included

Product Features

  • Wireless OBD ECU flashing allows compatible performance calibrations to be installed and updated through the M-Tuner v3 device following the initial ECU bench procedure.

  • Stage 1 and Stage 2 performance calibrations provide tuning options for compatible stock and modified McLaren M838T applications, with eligible off-the-shelf stage updates included for original purchasers.

  • Live Map Switching with four calibration slots allows drivers to select between 91-octane, 93-octane, 100+ octane, and Valet maps using factory vehicle controls.

  • Advanced datalogging and diagnostics provide live engine data monitoring, fault-code clearing, and dyno mode functionality for performance analysis and troubleshooting.

  • Additional ECU control features include automatic start/stop disable, left-foot braking, kickdown disable, and Loud Start functionality.

  • Expandable tuning capabilities support optional custom calibrations, ProTuning, and motorsport features for vehicles with extensive performance modifications.