SKU: 62516865524

HP EFI ECU & Harness Kits - 550-601

Sale price$1237.47 Regular price$1374.97
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Ships within 48 hours · Estimated delivery Jul 23 - Jul 28

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Description

HP EFI ECU & Harness Kits - 550-601Overview: 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: 62516865524

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Clumsyninja9
Lowell, US
★★★★★ 4
Great product even if it dies in a little over a year.
I bought this in May 2023 and it's July 2024. I went on a trip for 6 days and when I came back, it wouldn't turn on. It could possibly be because I've used it every day and suddenly stopped. Either way, I'm disappointed in the longevity of this product. For the price I expected more, but nothing is made to last any more. That being said, I love the design and rechargeable aspect. The cap is awesome for storage and clean up is super easy. This little machine packs a punch as long as you have enough liquid. I've never had issues with lumps or performance in general. I will purchase this product again to see if it was just a fluke.
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Reviewed in the United States on July 10, 2024
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Debsmusings
Belleville, US
★★★★★ 3
Bigger/sturdier than expected = good and bad. Recharging cable is USB to USB-C. Need old style brick
I like the design in that it comes with a cover that shields the wand in my utensil drawer but its a bit bigger than expected. So its a plus that its sturdier but a minus that it takes up more space. The USB-C cable is USB to USB-C and not USB-C to USB-C so I had to go fishing for an old brick. Am hoping it doesn't need to charge often. The indicator shows its plugged in but not whether charged.
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Reviewed in the United States on February 5, 2026
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Verified Purchase
Sarahi De Anda
Belleville, US
★★★★★ 5
Good
If this works very well, it is better than the others I have bought.
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Reviewed in the United States on May 14, 2026
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CK
Natrona Heights, US
★★★★★ 2
Ok
Got three years out of it. Better than some others. Docked two stars for lifespan. Docked another star for the paint finish which is not durable and marks easily. Should be more like $15 ?
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Reviewed in the United States on April 28, 2026
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Marcellita
Port Orchard, US
★★★★★ 5
I am very impressed!
This little frother is perfect and my frappé coffee tastes as if I were sitting at one of the hundreds cute, outside cafés in Thessaloniki. It whips stiff coffee foam in just a few seconds, holds charge for a long time, and appears to be of superior quality. Variable speed control is great, as it prevents the coffee liquid to splash when starting the frothing process. Granted, I have only owned it for about 2 weeks, but I am totally impressed, and hope it'll keep making delicious frappés for me for a long time to come. So far, highly recommend!
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Reviewed in the United States on June 8, 2026

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