SKU: 50413718991

Holley Sniper EFI Stealth 4500 Fuel Injection System 800HP-1500HP # HO550-841

Sale price$1687.50 Regular price$1875.00
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Description

Holley Sniper EFI Stealth 4500 Fuel Injection System 800HP-1500HP # HO550-841Holley Sniper EFI Stealth 4500 Fuel Injection System 800HP 1500HP # HO550 841 Fuel Injection System, EFI Stealth 4500, Polished, 1440 cfm, Gasoline, Kit Fuel Injection Style: Throttle body Fuel Injection System Type: Single 4 Barrel Throttle Body (4500 Flange) Maximum Horsepower with Gas: 1,500 Timing Control Compatible: Yes Power Adder Compatible: Yes ECM Included: Yes Self Tuning: Yes User Tunable: Yes Fuel Pump Included: No EGR: No Transmission

Holley Sniper EFI Stealth 4500 Fuel Injection System 800HP-1500HP # HO550-841
Fuel Injection System, EFI Stealth 4500, Polished, 1440 cfm, Gasoline, Kit
Fuel Injection Style:
Throttle body
Fuel Injection System Type:
Single 4-Barrel Throttle Body (4500 Flange)
Maximum Horsepower with Gas:
1,500
Timing Control Compatible:
Yes
Power Adder Compatible:
Yes
ECM Included:
Yes
Self Tuning:
Yes
User Tunable:
Yes
Fuel Pump Included:
No
EGR:
No
Transmission Controller Included:
No
Metering Style:
Speed density
Intake Manifold Included:
No
Multi-Port Fuel Rails Included:
No
Throttle Body Included:
Yes
Throttle Body Mounting Flange:
4500 Dominator
Venturi Quantity:
4
Venturi Diameter (mm):
54.00mm
Airflow Rate (cfm):
1,440 cfm
Throttle Body Material:
Aluminum
Throttle Body Finish:
Polished
Injectors Included:
Yes
Injector Size (lbs/hr):
100 lbs./hr.
Calibration Module Included:
Yes
Wiring Harness Included:
Yes
Oxygen Sensor Included:
Yes
Fuel Pressure Regulator Included:
No
Distributor Included:
No
MAP Sensor Included:
Yes
IAT Sensor Included:
No
TPS Sensor Included:
Yes
IAC Motor Included:
Yes
Quantity:
Sold as a kit.
Notes:
Not for use with engines producing less than 800 hp. For use with gasoline only. Use of leaded race fuels may shorten the service life of the WBO2 sensor.
Holley Sniper EFI Stealth 4500 Fuel Injection Systems
Holley Sniper EFI Stealth 4500 fuel injection systems are what you need to convert your dragster or Pro-street vehicle to fuel injection. For engines producing 800+ hp, the Sniper Stealth 4500 systems feature 8 100 lbs./hr. injectors and a throttle body that flows a massive 1440 cfm. These Holley systems come with a USB to CAN tuning cable and free downloadable Sniper EFI software to give you unlimited control of your engine. Holley Sniper Stealth 4500 systems will also look great under the hood in your choice of shiny, ceramic black, and classic gold finishes.Features and benefits include: Supports up to 1500 hp naturally aspirated or 1250 hp forced induction with 8 100 lbs./hr. injectors Compatible with draw-through or blow-through forced induction applications 2.125 in. throttle plates, flow 1440 cfm for large cubic inch engines 2.5Bar MAP sensor Integrated ignition timing control Programmable launch control via 2-step and timing retard. Both can be triggered by a trans-brake input Gen 3 Ultra Dominator-style 4-bolt air cleaner flange -8AN fuel inlets High-resolution full color touchscreen for initial setup, tuning, and gauge displays Simple calibration wizard--answer a few questions about your engine and it creates the base map, then starts tuning on its own! No laptop required Self-tuning ECU means you don't have to be a computer/tuning wiz to have EFI The included genuine Bosch LSU 4.9 wideband oxygen sensor provides real time Fuel Map Learn Built-in single-stage wet or dry progressive nitrous control Three programmable 0-5 V sensor inputs for oil/fuel/dome or nitrous pressure or other critical information Six programmable ground outputs, five programmable ground inputs. These can be used to trigger or control external devices, such as nitrous solenoids and boost control solenoids. Or to provide the ECU with an input to turn on function, such as an ignition timing One +5 V reference output, +5 V power supply for 0-5 V sensors, one sensor ground supply for 0-5 V sensors Throttle body mounted ECU--no extra boxes to mount Only 4 wiring connections required--battery +, battery -, switched ignition, and rpm Required external fuel pressure regulator, 12-848 is recommended Customizable secondary fuel pump output (TPS, rpm, or boost enabled) User-friendly boost control with handheld adjustability Free software included--comprehensive data logging tool to help you maximize the performance of your engine Real-time data logging to the included 3.5 in. touch screen allows you to save information to the SD card without needing a communication cable Programmable target air fuel ratios per boost level Advanced boost control available via free Sniper EFI tuning software, including boost vs. rpm and boost vs. time OEM-style TPS/IAC, for years of dependable service Included clamp-on oxygen sensor kit ensures a leak-free oxygen sensor installation, with stainless steel T-bolt clamps and a stainless steel (weldable) oxygen sensor flange
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: 50413718991

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Paige
Battle Creek, US
★★★★★ 5
Definitely worth the price
Size: 6.5, Color: Black/Black
Absolutely love these boots! I originally bought them to wear in NYC in December & they did not disappoint. They were comfortable, cute, durable and worked well in the slush/snow. The traction on the bottom is also nice! They kept me warm with wool socks. I wear them almost daily now. Perfect for everyday. easy to wear with variety of outfits. Good every day shoe.
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Reviewed in the United States on January 3, 2026
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Kimberly
Boise, US
★★★★★ 5
Snagged a deal
Size: 7, Color: Redwood/Gum 10
I waited and waited to get these boots! I knew I was chancing it, but they went on sale, and I snagged them! I am a size 7, and they fit nicely with socks. a little loose, barefooted, but what psycho wears boots without socks? They are comfortable and really well-made.
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Reviewed in the United States on April 8, 2026
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ashlynnk
Lowell, US
★★★★★ 4
Cute, comfortable waterproof boots (a little snug to put on)
Size: 7, Color: Velvet Tan/Gum 2
These are really cute Chelsea-style boots and feel very comfortable once they’re on. The waterproof material is great for wet weather and the sole feels sturdy with good traction. They look stylish enough to wear casually but still feel practical for rainy days. The only downside is they can be a little difficult to put on at first because the opening is somewhat snug, but once they’re on they fit well and feel supportive. Overall they’re a great waterproof boot and I’ve enjoyed wearing them.
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Reviewed in the United States on March 17, 2026
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Abby B
Charlottesville, US
★★★★★ 5
Surprisingly great for my wide feet and high instep!
Size: 10.5, Color: Velvet Tan/Gum 2
So thrilled I took a chance on these. Finding boots is impossible for me. I have wide feet, a super high instep, a bunion on one foot, and I wear a hard to find size (10.5). I ordered the 10.5 and 11 in these expecting I might need to size up for width (if I could even get them on). It was a struggle getting the 10.5s on the first time, and once I did they were somewhat uncomfortable on the top of my left foot. But I read that they would relax so decided to give it a go because I need waterproof boots for an upcoming trip and the 11s felt too long. After two days of light wear, they are already breaking in and I have no more discomfort. Getting them on is already easier and they are plenty wide enough and very comfortable to walk in. These are true to size. Super happy and worth a day of mild discomfort to break them in!
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Reviewed in the United States on March 7, 2026
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EE
Lowell, US
★★★★★ 5
Comfortable, sturdy, waterproof
Size: 9.5, Color: Black/Black
Loce, love, love these boots. Have walked ten miles with no foot pain around NYC. They go with everything and and are so comfortable. As they are waterproof/resistant, they get a little warm in high temps, but perfect three-season boots.
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Reviewed in the United States on May 17, 2026

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