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The HP EFI allows you to accurately control the fuel and ignition of your engine along with additional controls for nitrous, boost or water-meth.

SKU: WBD-554-113
SKU: WBD-554-113 Categories: , , , , ,


Looking for a plug-and-play alternative for your stock or late model factory EFI engine? How about a replacement ECU for your older Holley C950? Holley has you covered. HP EFI, ECU and harness kits are designed to be used with popular factory EFI engines as an alternative to the factory ECU and harness or as a replacement for your C950 ECU. The HP allows you to accurately control the fuel and ignition of your engine along with additional controls for nitrous, boost or water-methanol.


  • Quickstart ignition and fueling strategy for LSX engines
  • Data logger, scalable axes, smoothing, multiple graph viewability, pre-defined notes fields and many more features
  • Strip chart real-time data viewer
  • Integrated boost control, including boost vs time, boost vs gear (time or RPM), boost vs RPM, boost vs speed, launch control, boost launch builder, over-boost safeties, and boost scramble
  • Traction control, including power reduction via timing, nitrous percentage or boost (requires Davis Technologies Holley module)
  • Quickstart fueling for all engines
  • Option for VE-based fueling strategy
  • Fuel map and learn function smoothing
  • Configurable user password protection
  • Fully configurable laptop gauge panel


  • Optional 5.7” full-color LCD touchscreen allows easy on-the-fly tuning and data logging or can be used as an easy-to-see graphics gauge panel
  • Eight sequentially-driven 8:2 peak and hold injector drivers, capable of driving up to 16 low or high impedance injectors as a standard feature. Multiple staged injector strategies
  • Eight channel distributorless ignition DIS outputs capable of directly driving “Smart” ignition coils or Holley DIS coils
  • Plug-and-play control of factory GM 24x and 58x LSX engines
  • Integrated single channel wide band oxygen sensor control. Works with NTK or Bosch sensors
  • Internal data logging standard with 2GB of memory
  • 4 stage progressive nitrous control
  • Turbo boost control
  • Integrated water-methanol injection control
  • Self-tuning fuel table strategy greatly simplifies tuning process
  • Individual cylinder fuel and spark control allows you to unlock your engine’s potential
  • Works with 4, 6, or 8 cylinder engines
  • Unique pound per hour-based fueling strategy greatly simplifies and commonizes tuning
  • Advanced idle, closed loop, and enrichment strategies allow for very stable operation
  • ECU is fully potted and can be mounted in the engine compartment or interior
  • Sealed automotive and marine grade connectors
  • Allows for use of common OEM sensors, as well as customer sensor calibration input
  • Ignition plug and play with GM 24x and 58x LSX engines, GM HEI, Ford TFI, magnetic and hall effect trigger, and other ignition systems. Custom settings can be configured to allow for many other applications
  • 1-5 bar MAP sensor capability
  • Two channel knock control sensor inputs for one or two wire knock sensors
  • Dedicated fuel and oil pressure inputs
  • Controls both stepper and PWM idle air control (IAC) motors
  • Speed density, Alpha-N, or combination fueling strategies
  • 4 programmable high or low pulse width modulated (PWM) outputs and 4 fully configurable inputs
  • 4 stage nitrous oxide control
  • Fully featured nitrous control eliminates the need for a separate nitrous controller device
  • Can be configured wet or dry with closed loop feedback
  • Progressive control based on time, RPM, or boost
  • Lean or rich safety cutoff
  • Full timing retard and control configurability per stage based on RPM or time
  • Integrated water-methanol injection control
  • Uses Holley water-methanol solenoids specially designed and calibrated for use with this EFI system to allow the user to enter water-methanol flow as a percentage of fuel injector flow for tubing

Additional information

Weight 3.65 lbs
Dimensions 10 × 8 × 25 in