The 4150 Sniper Stealth EFI system converts a carbureted 4150-flange engine to self-tuning fuel injection while keeping carburetor styling. Four 100 lb/hr fuel injectors support up to 650 HP naturally aspirated or 600 HP under forced induction, and the throttle-body-mounted ECU handles fuel map self-learning and ignition timing control for improved idle stability, drivability, and wide-open-throttle power. For a complete installation, Master Kit part # 550-870K adds a full fuel system.
Key Features:
- Bolt-on 4150-flange carburetor replacement
- Throttle body mounted ECU — no extra boxes to mount
- Four 100 lb/hr fuel injectors, up to 650 HP support
- Includes high-pressure fuel crossover line
- All wiring exits below the rear fuel injector cover
- Integrated ignition timing control
- Self-tuning calibration wizard — no laptop required for setup
- 3.5 in. high-resolution full-color touchscreen for tuning and gauge displays
- Fuel map self-learning for improved idle stability and drivability
- Transmission kick-down provisions for GM TH350/400, 200R4/700R4 and Ford C4/C6
- Compatible with the Sniper ecosystem — Hyperspark ignition, fuel systems, air cleaners, throttle bodies, and Digital Dash
- Designed for at-home installation with just 4 simple connections
Specifications:
- Product Type: 4150 EFI Throttle Body System
- Flange: 4150
- CFM: 870
- Base Fuel Pressure: 58.5 PSI
- Finish: Shiny
- Injectors: 4 x 100 lb/hr
- Horsepower Support: Up to 650 HP naturally aspirated, up to 600 HP forced induction
- Transmission Kick-Down: GM TH350/400, 200R4/700R4, Ford C4/C6
- Part Number: 550-870
For a complete fuel system installation, Master Kit part # 550-870K includes an external fuel pressure regulator, 20 ft. of Vapor Guard fuel hose, fuel pump, filters, hardware, and a bulkhead fitting.
FAQ
How much horsepower can the 550-870 Sniper Stealth support?
It supports up to 650 HP naturally aspirated or up to 600 HP on forced induction applications with its four 100 lb/hr injectors.
Does this kit include a fuel system?
No — the base 550-870 does not include the external fuel system. Master Kit part # 550-870K adds the regulator, hose, pump, filters, and hardware for a complete installation.
Do I need a laptop to tune this system?
No. A self-tuning calibration wizard walks you through a few questions about your engine and begins self-tuning automatically, using the onboard 3.5 in. touchscreen.
What transmissions does it support kick-down for?
It includes kick-down provisions for GM TH350/400 and 200R4/700R4 transmissions, as well as Ford C4/C6 transmissions.
What flange does the 550-870 use?
It's a bolt-on 4150-flange system designed as a direct carburetor replacement.