Looking for a plug-and-play alternative for a stock or built late-model factory EFI engine, or a replacement for an older Holley C950 ECU? This HP EFI ECU and harness kit is designed to replace the factory ECU and harness on GM TPI and Holley Stealth Ram applications, adding accurate fuel and ignition control plus optional nitrous, boost, or water/meth control.
Key Features:
- Internal data logger with scalable axes, smoothing, and multiple graph views
- Sealed automotive and marine-grade connectors
- Advanced idle, closed-loop, and enrichment strategies for stable operation
- 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
- Plug-and-play control of factory GM 24x and 58x LSx engines
- Progressive nitrous control based on time, RPM, or boost (requires part number 554-111)
- Full timing retard/control configurability per stage, based on RPM or time
- Dedicated fuel and oil pressure inputs
- Optional 5.7" full-color touchscreen LCD for on-the-fly tuning, data logging, or gauge display
- Internal data logging with 2GB of memory
- 4 programmable PWM outputs and 4 fully configurable inputs
- Eight-channel Distributorless Ignition (DIS) outputs, compatible with Smart ignition coils or Holley DIS coils
- Speed density, Alpha-N, or combination fueling strategies
- Turbo boost control and integrated water/methanol injection control
Specifications:
- Application: GM TPI and Holley Stealth Ram™
- Ignition Type: Coil (no timing control), GM HEI small cap, or Holley Dual Sync distributor
- Injector Connector: Jetronic/Minitimer (Bosch type)
- Inputs/Outputs: 4 programmable inputs, 4 programmable outputs
- MAP Sensor: 1-5 Bar
- Oxygen Sensor: NTK
- What's Included: ECU, harness, communication cable, software, NTK wideband O2 sensor
- Part Number: 550-601N
If more than 4 inputs and 4 outputs are needed for the planned combination of controls, Holley recommends stepping up to the Dominator VMS. Free software and firmware updates are available for download.
FAQ
What applications is the 550-601N designed for?
It's built as a plug-and-play replacement for GM TPI and Holley Stealth Ram™ factory EFI systems, or as a replacement for an older Holley C950 ECU.
Does it support boost or nitrous control?
Yes. It offers turbo boost control and progressive nitrous control (nitrous requires part number 554-111), along with integrated water/methanol injection control.
What ignition types does this ECU support?
Coil with no timing control, GM HEI small cap, and Holley Dual Sync distributor ignition types.
Can I data-log with this ECU?
Yes, it includes internal data logging with 2GB of memory and an optional 5.7" full-color touchscreen for real-time viewing.
What oxygen sensor does this kit include?
It includes an NTK wideband oxygen sensor, recommended for leaded or methanol fuels and high exhaust temperature applications.
