Holley 550-841 Sniper EFI Stealth 4500 - Polished

Supports Up To 1500 HP - 3.5 in. LCD Touchscreen - 8 x 100 lb./hr. Injectors

Part Number: 550-841

Make your classic drive like a modern fuel injected vehicle, including better cold starts, smooth drivability, and improved fuel economy. Sniper Stealth 4500 was designed to be installed at home in your garage with a few tools and the support of Holley's comprehensive installation manuals and online videos. The high resolution 3.5” LCD touchscreen user-friendly setup wizard has you answer a few simple questions about your engine and the system will begin self-tuning with no laptop or tuning experience required. If you're looking for a high-performance fuel injection system that delivers power, efficiency, and ease of use, look no further than the 4500 EFI system. Take full control and make the conversion to EFI with ease with many additional accessories such as HyperSpark, air cleaners, digital dashes, and more. Featuring (8) 100 lb./hr. fuel injectors, the Stealth 4500 is a great option for any build looking to make between 800-1500 HP naturally aspirated or 1250 HP forced induction engines. This is a great pairing for dragster, pro street, and other aggressive applications with multiple input and output options for sensors, switches, and relays. Flowing 1440 CFM for larger cubic inch engines, the Dominator style main body four bolt air cleaner flange keeps increased amount of air moving. Included is a built in MAP sensor rated at 2.5 BAR and programmable launch control via 2-step along with a timing retard option, which can be triggered by the trans-brake input.

Features and Benefits

• (4) wiring connections required for throttle body installation (Battery+, battery-, switched ignition, and RPM)
• Customizable secondary output for fuel pump activated by throttle position, RPM, or boost signal
• Single stage pulse width modulated progressive or nonprogressive nitrous controller that’s capable of controlling nitrous and fuel solenoids for wet or dry nitrous setup
• -8AN fuel inlets for greater fuel delivery
• Integrated timing control for assisting with heavy boost, load conditions, or idle
• (3) programmable 0-5V sensor inputs for oil and fuel pressures or monitor nitrous and other critical information
• 1440 CFM for large cubic inch engines with 2.125” throttle plates
• Programmable boost control available, software includes Boost vs. RPM, Boost vs. Time Curve, set Target Launch Boost Control Pressure, and Target Air/Fuel Rations in relation to boost control levels
• (6) programmable ground outputs and (5) programmable ground inputs used to control external relays, switches, and other devices
• Bosch LSU 4.9 Wideband O2 Sensor provides real time fuel map learning, with a no welding stainless steel O2 flange and T-bolt clamps
• Compatible with blow through or draw through forced induction applications
• Supports up to 1500 HP naturally aspirated or 1250 HP forced induction
• Self-tuning ECU with intuitive setup calibration wizard creating a base tune
• 3.5” LCD touchscreen handheld for real time data logging, initial setup, tuning, and gauge displays to view and monitor parameters with SD card to save key information
• Dominator style 4 bolt air cleaner flange
• Programmable launch control via two-step along with a timing retard option, triggered with trans brake input
• OEM designed Throttle Position Sensor and Idle Air Control module for dependable reliability
• ECU mounted to throttle body removing extra mounting
• Built in 2.5 MAP sensor for improved performance

Not to be used on engines producing 800 HP or less. Racing fuels may shorten the service life of the O2 wideband sensor. Required Holley P/N 12-848 for external fuel pressure regulator or Holley P/N 12-848KIT that includes a gauge. For marine installations, a flame arrestor is legally required. We recommend Holley P/N 720-1 or 720-11 Flame Arrestor, along with Holley P/N 720-31 or 720-33 Flame Arrestor Vent Tube to ensure proper function, safety, and compliance.