The 4150 Super Sniper Stealth EFI system converts a carbureted 4150-flange engine to self-tuning fuel injection while keeping classic carburetor styling. Eight 100 lb/hr fuel injectors support up to 650 HP naturally aspirated or 1250 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.
Key Features:
- Bolt-on 4150-flange carburetor replacement
- Throttle body mounted ECU — no extra boxes to mount
- Eight 100 lb/hr fuel injectors, up to 1250 HP support (forced induction)
- Up to 650 HP support naturally aspirated
- Self-tuning calibration wizard — no laptop required for setup
- 3.5 in. high-resolution full-color touchscreen for tuning and gauge displays
- Integrated ignition timing control
- 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: Black
- Injectors: 8 x 100 lb/hr
- Horsepower Support: Up to 650 HP naturally aspirated, up to 1250 HP forced induction
- Handheld Included: No — self-tuning via onboard touchscreen
- Transmission Kick-Down: GM TH350/400, 200R4/700R4, Ford C4/C6
- Part Number: 550-877
For a complete installation with fuel system components, pair with a Sniper Stealth Master Kit or Holley's fuel system accessories.
FAQ
How much horsepower can the 550-877 Super Sniper Stealth support?
It supports up to 650 HP naturally aspirated or up to 1250 HP on forced induction applications with its eight 100 lb/hr injectors.
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 550-877 use?
It's a bolt-on 4150-flange system designed as a direct carburetor replacement.
Can this be expanded with other Sniper components?
Yes, it's part of the Sniper ecosystem and pairs with Holley's Sniper Hyperspark ignition, fuel systems, air cleaners, throttle bodies, and Digital Dash.