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ECU & Engine Management
ECU & Engine Management — Standalone EFI and LS Swap Solutions Engine management is the brain of a modern fuel-injected powertrain. The ECU processes data from dozens of sensors, calculates optimal fuel delivery and ignition timing thousands of times per...
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Holley EFI 550-904T
Holley EFI Terminator X - Gen III 4.8/5.3/6.0 GM Truck Engines
Terminator X ECU's are designed to be mounted...
Part TypeFuel Injection System£1,432.00£1,327.00 inc VAT£1,105.83 ex VAT -
Holley EFI 550-903T
Holley EFI Terminator X - GM LS1/LS6 - 24x Crank - 1x Cam - EV1
Terminator X ECU's are designed to be mounted...
Part TypeFuel Injection System£1,432.00£1,327.00 inc VAT£1,105.83 ex VAT -
Holley EFI 550-1070
Holley EFI Terminator X Stealth 4500 - Shiny - 8 Injectors - 800-1500
8 Injectors - 800-1500 HP
Part TypeFuel Injection System£2,986.99£2,864.99 inc VAT£2,387.49 ex VAT -
Holley EFI 550-1062
Holley EFI Terminator X Stealth GM LS 4150 - Gold - 58X Crank - 4
58X Crank - 4 Injectors - 650 HP
Part TypeFuel Injection System£2,352.98£2,253.98 inc VAT£1,878.32 ex VAT -
Holley EFI 550-1060
Holley EFI Terminator X Stealth GM LS 4150 - Shiny - 58X Crank - 4
58X Crank - 4 Injectors - 650 HP
Part TypeFuel Injection System£2,352.98£2,253.98 inc VAT£1,878.32 ex VAT -
Holley EFI 550-1022
Holley EFI Terminator X Stealth GM LS 4150 - Gold - 24X Crank - 4
24X Crank - 4 Injectors - 650 HP
Part TypeFuel Injection System£2,352.98£2,253.98 inc VAT£1,878.32 ex VAT -
Holley EFI 550-1020
Holley EFI Terminator X Stealth GM LS 4150 - Shiny - 24X Crank - 4
24X Crank - 4 Injectors - 650 HP
Part TypeFuel Injection System£2,352.98£2,253.98 inc VAT£1,878.32 ex VAT -
Holley EFI 550-1013
Holley EFI Terminator X Max Stealth 4150 - Gold - Pre-2009 GM
Not recommended for 4x4 applications with electronic transfer...
Part TypeFuel Injection System£2,454.98£2,317.99 inc VAT£1,931.66 ex VAT -
Holley EFI 550-1011
Holley EFI Terminator X Max Stealth 4150 - Shiny - Pre-2009 GM
Not recommended for 4x4 applications with electronic transfer...
Part TypeFuel Injection System£2,454.98£2,317.99 inc VAT£1,931.66 ex VAT -
Holley EFI 550-1003
Holley EFI Terminator X Stealth 4150 - Gold - 4 Injectors - 650 HP
4 Injectors - 650 HP
Part TypeFuel Injection System£2,045.99£1,972.00 inc VAT£1,643.33 ex VAT -
Holley EFI 550-1001
Holley EFI Terminator X Stealth 4150 - Shiny - 4 Injectors - 650 HP
4 Injectors - 650 HP
Part TypeFuel Injection System£2,045.99£1,972.00 inc VAT£1,643.33 ex VAT -
APR ms100229
APR FUELING - STAGE 3+ MPI - APR Port Injection System (2.0T EA888.3)
Please Note: This system is designed for use...
Part TypeFuel Injection System£1,483.99£1,264.99 inc VAT£1,054.16 ex VAT -
APR ms100111
FUELING KIT, NORTH AMERICAN MQB - APR Fueling - Stage 3+ MPI and LPFP - 2.0T EA888 Gen 3
Please note, this system is only designed for...
Part TypeFuel Injection System£1,789.99£1,516.99 inc VAT£1,264.16 ex VAT -
APR em100043
ECU MG1CS163 UNLOCK - APR ECU Unlock Service for Bosch MG1CS163 ECUs (8Y RS3/Formentor)
How to Purchase and Install APR Software |...
Part TypeEngine Control Module (ECM)£1,637.99 inc VAT£1,364.99 ex VAT -
Haltech HT-150721
Haltech ECU Kit - Elite 950 - 24X - Ev1 Injector Connectors
HALTECH ECU KIT - ELITE 950 - 24X...
Part TypeECU Kit£1,530.00 inc VAT£1,275.00 ex VAT -
BP Automotive ECK-501
Bp Automotive GEN V L86 Harness and ECU Kit for 8L90 Transmission
BP AUTOMOTIVE GEN V L86 HARNESS AND ECU...
Engine TypeGen V LT£3,599.99 inc VAT£2,999.99 ex VAT -
BP Automotive ECK-500
Bp Automotive GEN V L86 Harness and ECU Kit for 6L80-6L90E Transmission
BP AUTOMOTIVE GEN V L86 HARNESS AND ECU...
Engine TypeGen V LT£2,399.99 inc VAT£1,999.99 ex VAT -
Aces EFI AS2011
Aces Jackpot PRO LS EFI - with Trans Control
Specifications: Reluctor Wheel Compatibility: 24x & 58x DBW...
Engine TypeGen III/Gen IV LS£1,576.79 inc VAT£1,313.99 ex VAT -
Aces EFI AS2011-1
Aces Jackpot LS EFI System - no Trans Control
Specifications: Reluctor Wheel Compatibility: 24x & 58x DBW...
Engine TypeGen III/Gen IV LS£971.99 inc VAT£809.99 ex VAT -
Haltech HT-220204
Rebel LS Kit - Suits Gen IV LS
6-pin DBW | EV6 Injectors | Manual Transmission
Engine TypeGen III/Gen IV LS£1,255.00 inc VAT£1,045.83 ex VAT -
Haltech HT-151365
Elite 2500 GM GEN IV LS2 non DBW Terminated Harness Kit EV6
Overview ECU OVERVIEW Elite 2500 is a two-connector,...
Engine TypeGen III/Gen IV LS£2,428.00 inc VAT£2,023.33 ex VAT -
Haltech HT-151364
Elite 2500 GM GEN IV LS2 non DBW Terminated Harness Kit EV1
Overview ECU OVERVIEW Elite 2500 is a two-connector,...
Engine TypeGen III/Gen IV LS£2,428.00 inc VAT£2,023.33 ex VAT -
Haltech HT-151367
Elite 2500 GM GEN IV LS2 DBW Ready Term Harn Kit - EV6
Overview ECU OVERVIEW Elite 2500 is a two-connector,...
Engine TypeGen III/Gen IV LS£2,428.00 inc VAT£2,023.33 ex VAT -
Haltech HT-151362
Elite 2500 GM GEN III LS1 (DBW Ready) Term Harn Kit - EV1
Overview ECU OVERVIEW Elite 2500 is a two-connector,...
Engine TypeGen III/Gen IV LS£2,428.00 inc VAT£2,023.33 ex VAT -
Holley EFI 550-1431
Holley Terminator X Max Kit - Ford Godzilla
ECU is not recommended for marine applications, but...
Part TypeFuel Injection Conversion Kit£1,789.99£1,693.00 inc VAT£1,410.83 ex VAT
ECU & Engine Management — Standalone EFI and LS Swap Solutions
Engine management is the brain of a modern fuel-injected powertrain. The ECU processes data from dozens of sensors, calculates optimal fuel delivery and ignition timing thousands of times per second, and adjusts in real time to maintain performance, efficiency, and engine protection across all operating conditions. Choosing the right engine management system — and ensuring it's correctly wired and calibrated — is one of the most consequential decisions in any performance build or engine swap project.
With over 200 engine management products from Holley EFI, Haltech, MSD, and related specialists, Billy's Speed Shop stocks a comprehensive range of ECUs, engine wiring harnesses, and control modules for everything from plug-and-play LS swap solutions to fully configurable standalone systems capable of managing the most complex race engine combinations.
Standalone EFI Systems — Complete Engine Management
Standalone EFI systems replace the factory engine management entirely, providing full user-configurable control over fuel delivery, ignition timing, launch control, boost control, and ancillary functions. The major advantage of a standalone system over a factory ECU is the ability to tune freely without dealer-level tools, integrate non-factory sensors and components, and expand the system's capabilities as the build evolves.
For LS swap applications, standalone systems eliminate the complexity of adapting a factory LS ECU to a non-factory vehicle — avoiding the need for security bypass modules, instrument cluster integration challenges, and the limitations of tuning a system that wasn't designed for aftermarket modification. A quality standalone ECU provides a clean, known starting point with full tuning capability from day one.
Engine Wiring Harnesses — Clean Installation
The engine wiring harness connects the ECU to every sensor, actuator, and control system on the engine. On LS swap and EFI conversion projects, a quality harness is the difference between a professionally executed installation with reliable long-term function and a problematic build where the wiring is a constant source of intermittent faults and troubleshooting. Our harness range includes pre-terminated, labelled harnesses designed for specific engine and ECU combinations, eliminating the time and risk associated with building a custom harness from scratch.
Engine Control Modules and Brackets
Factory LS ECUs — used in applications where a factory-based tune is preferred — require correct mounting solutions that protect the module from vibration, heat, and moisture. ECU mounting brackets position the module securely in a suitable location within the engine bay or interior, with appropriate ventilation and protection. Wiring harness extensions and bulkhead connectors facilitate clean harness routing through firewalls and between engine and interior.
EFI Conversion Kits
Complete EFI conversion kits provide everything needed to convert a carburetted engine to fuel injection in a single package — throttle body, ECU, harness, sensors, and fuel system components selected and matched for compatibility. These kits dramatically simplify what would otherwise be a complex multi-component sourcing exercise and are available in configurations suited to both traditional carburetted V8 engines and LS-based builds.



