Pay in installments of $374.99 with
,
and
Shipping Estimate
USA
- USA
- CAN
- USA
- CAN
Ships within 48 hours · Estimated delivery Aug 7 - Aug 12
Promo Codes Available:
For Your Every Summer RSVP, with Code: SUMMER15
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:
- 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
4.1 ★★★★★
Based on 7 reviews
Sort
Product Reviews
★★★★★ 5
Exactly what I was looking for
Size: 9-9.5, Color: Black Denim Blue
Perfect for what I wanted in an active casual shoe. Love the tread, it's both grippy and durable but flexible, the fit, adjustability, easy to take on and off, perfect amount of cushion and stability. Can wear with or without socks comfortably.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 7, 2026
★★★★★ 5
Excellent value!
Size: 10.5, Color: Black
Very well Made. Just received these and was surprised at the quality of the materials and they way they look. Much higher quality than the oriental point. They are comfortable and fit very well. I ordered 10.5, nice room in the box. I have not worn them yet, first impressions are positive. I will update after wearing them for awhile. So far, very happy with the purchase! Black and orange color looks great!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 15, 2026
★★★★★ 5
Perfect fit
Size: 9-9.5, Color: Blue/Grey
I think these shoes are excellent.
I ordered a pair which arrived after 2 days.
Contrary to some reviews I do not find these water shoes a tight fit at all. And I have bunions. Indeed I find them very comfortable. I have used them in water and as advertised they drain dry pretty quickly.
In short I am delighted with the shoes. So much so that I ordered a second pair. Different colour of course.
They just arrived and I am wearing them now. Same size and just as comfortable.
Thank you.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 30, 2026
★★★★★ 1
One day of use, then it rubbed against my toes and caused cuts
Size: 9-9.5, Color: Black Denim Blue, Size: 9-9.5, Color: Black Denim Blue
I got these right before a trip to Costa Rica where we would be doing a lot of hiking, some tubing, and be in and out of water. They felt great when I first tried them on and I was optimistic.
Our first day, we hiked a total of about 5 miles in the forest and along a river, with some swimming in pools throughout the hike. These weren't difficult trails, but a mix of gravel, rock, dirt, etc. The shoes felt fantastic and were comfortable all day. Later that evening, after they had mostly dried out, we did another mile or so to some other pools and I had no problem. During that hike I was so happy I was actually talking to my kids about what great things I was going to say in a review.
The following day however, as soon as I put on the sandals, just walking to the hotel pool, the top of the shoe, just above my big toes, was bending and rubbing against my toes. It was very noticeable and I took them off and made sure there was no sand or anything else causing the irritation. I had no other choice that day and we ended up back on a similar trail, hiking a total of about 1.5 miles, with it rubbing against my toes the entire time.
I tried both tightening and loosening the shoes and changing my stride to step more flat footed so they wouldn't bend at the back of my step, but that didn't help. Neither did getting them wet again, hoping to soften something up. By the time we were half way through that hike, there were visible raw spots on top of both my big toes. By the time we were done, they had become sores and very painful.
The following day, we walked on the sidewalk to breakfast about three blocks away and it hurt bad enough that I found a store and bought a pair of flip-flops instead. I haven't worn the sandals since.
I can't tell exactly what's going on inside the shoe, but I think the leathery part of the shoe is pushing down at the natural break in the toe area when I step, and the mesh is rubbing.
Since I've worn them outside and been swimming in them, I can't return them, but they're basically useless after one good day.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on November 29, 2025
★★★★★ 5
Great headphones!
Color: Black
Great headphone! They work well and sound quality was pretty good. Definitely worth the money. I love that they’re not inserted into the ear. It allows me to hear things going on around me but not so much that I can’t hear my music. They’re pretty comfortable too! I have smaller ears and the earbuds that you put into your ear tend to hurt after some time. These typically don’t.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 13, 2026
recommand products
Draper Heavy Duty Steel Shelving Unit, 5 Shelves, L1220 x W450 x H1830mm 21663
132.99
Draper Vehicle Key Fob Tester 24446
51.99
12mm Silicone Mold For Round Ball Beads
10.00
Draper Engine Timing Kit ETK134 (BMW) 27229
89.99
Draper Engine Timing Kit ETK155 (Fiat, Alfa Romeo, Chrysler, Lancia) 26954
51.99