Search our extensive catalogue for the required part:
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...
-
Holley EFI 558-134
Faisceau principal 58X LS allongé - LS2/3/7+ (58x/4x) - Longueur étendue
For Dominator, HP, Terminator X and Terminator X...
Part TypeEngine Wiring Harness£736.00 inc VAT£613.33 ex VAT -
Holley EFI 558-133
Faisceau principal LS 24X allongé - LS1/6 (24x/1x) - Longueur allongée
For Dominator, HP, Terminator X and Terminator X...
Part TypeEngine Wiring Harness£736.00 inc VAT£613.33 ex VAT -
Holley EFI 558-128
Faisceau principal pour Ford Foxbody 5.0L - Holley EFI
The following guide overviews all connections on the...
Part TypeEngine Wiring Harness£632.99 inc VAT£527.49 ex VAT -
Holley EFI 558-126
FAISCEAU PRINCIPAL À CÂBLE VOLANT - Faisceau principal à câble volant non terminé de 4,57 m (15 pi)
Pre-Terminated J1A / J1B 15' Flying Lead Main...
Part TypeEngine Wiring Harness£460.00 inc VAT£383.33 ex VAT -
Holley EFI 558-125
FAISCEAU SECONDAIRE, FORD COYOTE TI-VCT - Faisceau secondaire Holley EFI Ford Coyote Ti-VCT (2013-2017)
Designed to be used with 558-319 Main Power...
Part TypeEngine Wiring Harness£431.99 inc VAT£359.99 ex VAT -
Holley EFI 558-124
FAISCEAU SECONDAIRE, FORD COYOTE TI-VCT - Faisceau secondaire Holley EFI Ford Coyote Ti-VCT (2011-2012)
Designed to be used with 558-319 Main Power...
Part TypeEngine Wiring Harness£305.99 inc VAT£254.99 ex VAT -
Holley EFI 558-122
FAISCEAU PRINCIPAL, FORD COYOTE TI-VCT SMART - Faisceau principal Holley EFI Coyote Ti-VCT pour bobines Holley EFI HP Smart (2011-2017)
Requires MAP Sensor P/N 538-24 Designed to be...
Part TypeEngine Wiring Harness£1,024.99 inc VAT£854.16 ex VAT -
Holley EFI 558-110
FAISCEAU PRINCIPAL, FORD COYOTE TI-VCT - Faisceau principal Holley EFI pour moteur Ford Coyote avec Ti-VCT et bobines d'origine (2011-2017)
Requires MAP Sensor P/N 538-24 When utilizing this...
Part TypeEngine Wiring Harness£917.99 inc VAT£764.99 ex VAT -
Holley EFI 554-166
Module d'entrée/sortie CAN, sans faisceau - Module d'entrée/sortie CAN Holley EFI - Sans faisceau
Dominator and HP requires V6 software version Build...
Part TypeEngine Control Module (ECM)£460.99 inc VAT£384.16 ex VAT -
Holley EFI 554-165
Module d'entrée/sortie CAN avec faisceau - Kit module d'entrée/sortie CAN Holley EFI
Dominator and HP requires V6 software version Build...
Part TypeEngine Control Module (ECM)£562.00 inc VAT£468.33 ex VAT -
Holley EFI 554-119
Calculateur électronique HOLLEY EFI TERMINATOR - Calculateur électronique Terminator EFI
ECU is not recommended for marine applications, but...
Part TypeEngine Control Module (ECM)£2,470.99 inc VAT£2,059.16 ex VAT -
Holley EFI 554-114
Calculateur électronique HOLLEY EFI DOMINATOR - Calculateur électronique Dominator EFI
When utilizing a Transbrake, it is mandatory to...
Part TypeEngine Control Module (ECM)£2,454.98 inc VAT£2,045.82 ex VAT -
Holley EFI 554-113
Calculateur HOLLEY EFI HP - Calculateur EFI HP
When utilizing a trans brake, it is highly...
Part TypeEngine Control Module (ECM)£2,191.99 inc VAT£1,826.66 ex VAT -
Holley EFI 550-628n
KIT HP EFI FORD COYOTE, NTK O2, USCAR INJ - Kit HP EFI compatible Ford Coyote Ti-VCT, NTK O2
Calculateur HP EFI avec faisceau d'alimentation, faisceau principal,...
Part TypeEngine Control Module (ECM)£3,128.99 inc VAT£2,607.49 ex VAT -
Holley EFI 550-628
KIT HP EFI FORD COYOTE, BOSCH O2, USCAR INJ - Kit HP EFI compatible Ford Coyote Ti-VCT, Bosch O2
Calculateur HP EFI avec faisceau d'alimentation, faisceau principal,...
Part TypeEngine Control Module (ECM)£2,865.98 inc VAT£2,388.32 ex VAT -
Holley EFI 550-615
TERMINATOR MPFI, 4.8-6.0 PREMIERS CAMIONS - W - Kit Terminator LS MPFI
Moteurs de camions 4.8/5.3/6.0 (1997-2007) avec capteur de...
Part TypeFuel Injection System£4,372.00 inc VAT£3,643.33 ex VAT -
Holley EFI 550-614
Kit Terminator MPFI pour camions 4.8-6.0 (premiers modèles) - Kit Terminator LS MPFI
Moteurs de camions 4,8/5,3/6,0 L (1997-2007) avec capteur...
Part TypeFuel Injection System£2,970.98 inc VAT£2,475.82 ex VAT -
Holley EFI 550-613
Kit Terminator MPFI, LS2/3 et modèles récents - avec DB - Terminator LS MPFI
Moteurs GM LS2/LS3 et moteurs de camions 4.8/5.3/6.0...
Part TypeFuel Injection System£4,687.99 inc VAT£3,906.66 ex VAT -
Holley EFI 550-501
KIT DE RÉNOVATION UNIVERSEL HP POUR 4500 INTAK - Kits de mise à niveau universels HP EFI MPI
Kit de conversion universel HP EFI MPI 4500...
Part TypeFuel Injection System£5,003.99 inc VAT£4,169.99 ex VAT -
Holley EFI 550-500
KIT DE RÉNOVATION UNIVERSEL HP POUR 4150 INTAK - Kits de mise à niveau universels HP EFI MPI
Kit de conversion universel HP EFI MPI 4150ž...
Part TypeFuel Injection System£3,950.99 inc VAT£3,292.49 ex VAT -
Hilborn 550-718
Hilborn Terminator X MPFI Universel
Kit Terminator X MPFI universel pour systèmes EFI...
Part TypeFuel Injection System£1,755.54£1,403.95 inc VAT£1,169.96 ex VAT -
Brothers Trucks EH04880DISTRIBUTR
Faisceau de câbles moteur American Auto Wire - SB V8 - Sortie : Capteur derrière le distributeur
Compatible avec le faisceau de câblage moteur de...
Part TypeEngine Wiring Harness£493.00 inc VAT£410.83 ex VAT -
Brothers Trucks EH03680-HMANUAL
Faisceau moteur Brothers Trucks - V8 - Boîte manuelle - Allumage électronique
Câble de remplacement compatible avec les camions Chevrolet/GMC...
Part TypeEngine Wiring Harness£277.99 inc VAT£231.66 ex VAT -
Brothers Trucks EH03680-HAUTO
Faisceau moteur Brothers Trucks - V8 - HEI
Câble de remplacement compatible avec les camions Chevrolet/GMC...
Part TypeEngine Wiring Harness£253.00 inc VAT£210.83 ex VAT -
Brothers Trucks EH03680AUTO
Faisceau de câbles moteur Brothers Trucks - Moteur V8 - Transmission automatique
Compatible avec les moteurs de remplacement des camions...
Part TypeEngine Wiring Harness£235.99 inc VAT£196.66 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.



