This is the standalone Holley HP EFI ECU, including USB cable and software, built as a plug-and-play alternative for a stock or built late-model factory EFI engine — or as a replacement for an older Holley C950 ECU. The HP ECU delivers accurate fuel and ignition control, with additional support for nitrous, boost, or water/meth as the build evolves.
Key Features:
- Certified to ISO 8846, SAE J1171, and United States Coast Guard requirements for ignition protection and fire resistance
- Plug-and-play control of factory GM 24x and 58x LSx engines
- Ignition plug-and-play with GM 24x/58x LSx, GM HEI, Ford TFI, magnetic and hall-effect trigger, and other ignition systems
- Eight sequentially driven 8:2 peak-and-hold injector drivers, supporting up to 16 low or high impedance injectors
- Eight-channel Distributorless Ignition (DIS) outputs, compatible with Smart ignition coils or Holley DIS coils
- Integrated single-channel wideband oxygen sensor control, works with NTK or Bosch sensors
- Two-channel knock control sensor inputs for one or two-wire knock sensors
- 1-5 Bar MAP sensor capability
- 4 programmable PWM outputs and 4 fully configurable inputs
- Internal data logging with 2GB of memory, plus a real-time strip chart data viewer
- Integrated boost control: boost vs. time, gear, RPM, and speed, with launch control and boost scramble
- 4-stage progressive and non-progressive nitrous oxide control, wet or dry with closed-loop feedback
- Integrated water/methanol injection control using Holley water/meth solenoids for precise flow-percentage tuning
- Self-tuning fuel table strategy with speed density, Alpha-N, or combination fueling strategies
- Configurable user password protection
Specifications:
- Product Type: HP EFI ECU (standalone)
- Oxygen Sensor Control: Integrated single-channel wideband, NTK or Bosch compatible
- MAP Sensor: 1-5 Bar
- Inputs/Outputs: 4 programmable PWM outputs, 4 configurable inputs
- Data Logging: Internal, 2GB memory
- What's Included: ECU, USB cable, software
- Part Number: 554-113
When using a trans brake, Holley recommends installing its trans brake input protection device (part number 554-128) to protect the ECU from flyback voltage when the trans brake is released.
FAQ
Does this listing include a wiring harness?
No, this is the standalone HP EFI ECU with USB cable and software; harness kits are sold separately.
What ignition systems does it support?
Plug-and-play with GM 24x/58x LSx engines, GM HEI, Ford TFI, magnetic and hall-effect trigger ignition systems.
How many injectors can it drive?
Its eight sequentially driven peak-and-hold injector drivers support up to 16 low or high impedance injectors.
Does it support boost, nitrous, and water/meth control?
Yes, all three are integrated — boost control, 4-stage progressive nitrous control, and water/methanol injection control using Holley's water/meth solenoids.
Do I need extra protection when running a trans brake?
Holley recommends installing its trans brake input protection device, part number 554-128, to protect the ECU from flyback voltage when the trans brake is released.
