SKU: 94576912423

HP EFI ECU & Harness Kits - 550-601N

Sale price$1349.97 Regular price$1499.97
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Ships within 48 hours · Estimated delivery Aug 5 - Aug 10

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Description

HP EFI ECU & Harness Kits - 550-601NOverview: 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

Overview:

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.

Features:

  • NEW V2 SOFTWARE FEATURES
  • “Quick Start” ignition and fueling strategy for LS x Engines
  • Data Logger. Scalable axes, Smoothing, Multiple graph view ability, Pre-defined notes fields and many more
  • Strip Chart Real-Time Data Viewer
  • Integrated Boost Control - Boost vs Time, Boost vs Gear (Time or RPM), Boost vs RPM, Boost vs Speed, Launch control. Boost launch builder, Over-boost safeties, Boost scramble
  • Traction Control - Power reduction via timing, nitrous percentage or boost (Requires Davis Technologies Holley Module)
  • “Quick Start” fueling for all engines
  • Option for VE based fueling strategy
  • Fuel Map and Learn Function Smoothing
  • Configurable User Password Protection
  • Fully Configurable lap top Gauge Panel
  • FEATURES
  • 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
  • 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 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 24x and 58x LSx engines, 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
  • 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

Application:

Year Make Model Submodel Engine Size
Universal

Specs:

Brand Holley EFI
Emission Code 3
Ignition Type Coil - (No Timing Control)
Ignition Type GM HEI Small Cap
Ignition Type Holley Dual Sync Distributor
Injector Connector Jetronic / Minitimer (Bosch)
Product Type HP EFI Kit
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 94576912423

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Reviewed in the United States on March 7, 2026
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Daniel Krueger
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★★★★★ 5
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Scent: Citrus, Size: 2 Fl Oz (Pack of 1)
Been using this product for about 8 months, its all i use. As soon as I get out of the shower, I use it. Then at bed time. I use nothing else. I wish I knew about this Beef tallow sooner. I am 60, and will continue to use this. My face has never been softer. and My wrinkles are definitely not as prominent. Great product!!!! Great Price!!!!! Just but it and try it. You you know instantly. Your face will feel so soft, and moisturized . And its Not Greasy.
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Reviewed in the United States on May 25, 2026
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Pam S
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★★★★★ 4
Great Skin Conditioner
Scent: Unscented, Size: 2 Fl Oz (Pack of 1)
I ordered the unscented, and it is truly unscented. It is solid, but by rubbing you finger around the top of the tallow, it immediately begins softening and melting. I used too much the first time, as it leaves a sticky/tacky film on the skin, so as the instructions say, a little goes a long way. Even though the next time I was careful to use very little, I do think it leaves a little tacky and greasy feeling, but it does soften and protect the skin. My only complaint is that due to the size of the jar, and if you have long fingernails, you can't just rub your finger on top of the tallow without getting it all under your fingernails. I'd like the jar to be changed to a short wide mouth vessel, hence only a 4 star rating.
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Reviewed in the United States on March 6, 2026
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Bambi Forester
Boise, US
★★★★★ 5
Excellent ingredients and product!!
Scent: Unscented, Size: 4 Fl Oz (Pack of 1)
I rarely do reviews, but I am extremely impressed with this product and company. First it comes in beautiful packaging, the ingredients are pure, great, and so healthy! The price is good, and there isn’t any rancid smell which has been an issues with other similar products I’ve bought. I specifically bought the unscented to make sure it didn’t smell rancid, and it doesn’t. If I had one criticism it’s that there isn’t a phone number for contact just the website. I’m elderly, so I prefer to talk with someone. But, after I just experienced 2 bad experiences with similar products that I had to return, I so happy that I ordered this one. And, I’m so impressed that I’m going to order more now! 😁 Thanks 🙏 Terra Lotus for providing us with a great 👍 product!! Bambi Forester
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Reviewed in the United States on May 23, 2026
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Elizabeth
Charlottesville, US
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Worked well with us!
Scent: Citrus, Size: 2 Fl Oz (Pack of 1)
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