Item # 22876 BRAND: Holley

Holley Sniper EFI Stealth 4500 - Classic Gold Finish 550-843

Sniper EFI Stealth 4500 - 8 Injector - 800-1500 HP
Sniper EFI Stealth 4500 - 8 Injector - 800-1500 HP
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Sniper EFI Stealth 4500 - 8 Injector - 800-1500 HP

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Holley Sniper EFI Stealth 4500 - Classic Gold Finish 550-843

Product Overview:


Introducing the Sniper Stealth 4500 EFI System! Wanting to convert your Dragster or Pro-street vehicle to Fuel Injection? Look no further! The Sniper Stealth 4500 EFI system from Holley features 8, 100LB/HR Fuel Injectors capable of supporting 800 to 1500 HP naturally aspirated, or 800-1250 HP on forced induction applications. The Sniper Stealth 4500 also features multiple Input and Output options for sensor inputs and switched outputs to control external relays. This system also comes with a USB to CAN tuning cable and free downloadable Sniper EFI Software give you unlimited control of your engine


  • Supports up to 1500 HP Naturally Aspirated or 1250 HP Forced Induction with Eight 100 Lb/Hr Injectors
  • Compatible with Draw through or Blow through forced induction applications
  • 2.125” 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 realtime Fuel Map Learn
  • Built-in Single Stage Wet or Dry progressive nitrous control
  • Three Programmable 0-5V 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, boost control solenoids. Or to provide the ECU with an Input to turn on function such as an ignition timing
  • One +5v Reference Output - +5V Power Supply for 0-5v Sensors, One Sensor Ground – Ground supply for 0-5v Sensors
  • Throttle body mounted ECU – no extra boxes to mount
  • Only 4 Wiring Connections Required! (Battery +, Battery - , Switched Ignition & 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 datalogging tool to help you maximize the performance of your engine
  • Real-time datalogging to the included 3.5” 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
  • Patent Pending


1 Year Manufacturers Warranty


Brand: Holley Sniper EFI<br> CFM: 1440<br> Coast Guard Approved: Yes<br> Emission Code: 3<br> Finish: Classic Gold<br> Flange Size: 4500<br> Flange Style: 4500<br> Fuel Pressure: 58.5 PSI<br> Height: 3.85"<br> Injector Size: 100 lb/hr @ 58.5 PSI<br> Inlet / Outlet Size: 8AN<br> MAP Sensor: 2.5Bar<br> Max Horsepower Rating: 1250 Forced Induction, 1500 Naturally Aspirated<br> Product Type: Sniper EFI Stealth 4500<br> Throttle Bore: 2.125 inch<br> Part Number: 550-843<br> <b>EMMISIONS</b><br><br> <p>This part is legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles and Racing Use Only Vehicles.</p><br /> <p>The following vehicles are considered Uncontrolled (Non-Emissions Controlled) Vehicles:</p><br /> • 1965 and older U.S. manufactured California Certified vehicles<br /> • 1967 and older U.S. manufactured Federally Certified vehicles<br /> • 1967 and older Foreign manufactured vehicle<br /><br /> The following vehicles are considered Racing Use Only Vehicles: <br /><br /> • Racing Use Only Vehicles are vehicles that are used exclusively for competition and that are not registered and that may never be used on the street<br /><br /> <b><u>WARNING: It is against the law to install this part on an Emissions Controlled Vehicle</u></b><br /><br /> The following vehicles are considered Emissions Controlled Vehicles: <br /><br /> • 1966 and newer U.S. manufactured California Certified vehicles<br /> • 1968 and newer U.S. manufactured Federally Certified vehicles<br /> • 1968 and newer Foreign manufactured vehicle

In the Box


(1) Holley Sniper EFI Stealth 4500 - Classic Gold Finish 550-843

Guides & Accessories


<p><a href="" target="_blank"><i><b>Instructions for 550-843</b></i></a></p> <p><a href="" target="_blank"><i><b>Quick Start Guide for 550-843</b></i></a></p><br /> ***Not for use with engines producing less than 800 horsepower ***Gasoline Only ***Use of leaded race fuels may shorten the service life of the WBO2 sensor


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Questions & Answers

Will this work on the M9424-G429 motorsport intake on a 514cu in with 639hp?

Asked by: Shorty
That intake has the 4150 style flange, for that you'd want this option: The 800 CFM Main Body will support 700 Horsepower for a Naturally Aspirated engine
Answered by: Bart
Date published: 2022-06-13
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Holley Sniper EFI Stealth 4500 - Classic Gold Finish 550-843
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