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    550-604N-8-16  Holley HP EFI ECU and Harness Kit-  Universal V8  for 8 or 16

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      Purchase 550-604N-8-16 Holley HP EFI ECU and Harness Kit- Universal V8 for 8 or 16

      SKU: HLY-550-604N-8-16
      550-604N-8-16 Holley HP EFI ECU and Harness Kit- Universal V8 for 8 or 16



      For  8  or    16 injector Systems  -  

      Holley HP EFI systems are equipped with 4 programmable inputs and 4 programmable outputs that are ideal for most vehicles with a single power adder. This feature allows the user to configure the system to support a wide range of controls including boost control, progressive nitrous, water/meth injection, speed inputs, fuel pump control, AC inputs, timing retard inputs and various other uses. When selecting an ECU, users need to ensure their planned controls can be run with the 4 inputs and 4 outputs as certain combinations may use more I/Os than are available. If more I/Os are required, users should choose the Dominator VMS.

      If Transmission control is desired , you need the Dominator

      Will control 16 injectors  all together *  will require a 16 injector harness.   558-207  
      See Dominator  ECU  to control injectors  Staged   or Sequential 

      Looking for a plug and play alternative for your stock or built 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 meth.


      • Optional 5.7” full-color touchscreen LCD allows easy on-the-fly tuning, data-logging or can be used as an easy to see graphical 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. Will drive 2 wire coils with the addition of PN 554-112 high current coil driver module
      • Integrated single channel wide band oxygen sensor control. Works with NTK or Bosch sensors
      • Internal data-logging standard with a huge 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, 8 cylinder engines
      • Unique lb/hr 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 HEI, Ford TFI, magnetic and hall effect trigger, and other ignition systems. New Plug and Play applications in process. Custom settings can be configured to allow many other applications
      • 1-5 Bar MAP sensor capability
      • Two channel knock control sensor Inputs for both 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 can be configured for use
      • 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, requires part # 554-111 Harness 
      • Lean or rich safety cutoff
      • Full timing retard/control configurability per stage based on RPM or time
      • Integrated Water/Methanol injection control
      • Uses Holley Water/Meth solenoids specially designed and calibrated for use with this EFI system to allow the user to enter Water/Meth flow as a percentage of fuel injector flow for Water/Meth tuning precision unmatched in the industry