The Holley Sniper EFI Stealth 4500 converts a carbureted dragster or pro-street engine to modern fuel injection while keeping the classic look of a 4500-flange throttle body. It's built around eight 100 lb/hr fuel injectors that support 800-1500 HP naturally aspirated or up to 1250 HP with forced induction, and the self-tuning ECU walks you through setup on a bright 3.5" touchscreen — no laptop or tuning background required.
Key Features:
- Supports up to 1500 HP naturally aspirated or 1250 HP forced induction
- Eight 100 lb/hr fuel injectors
- Compatible with draw-through or blow-through forced induction setups
- 2.125" throttle plate flowing 1440 CFM
- Integrated ignition timing control
- Programmable launch control via 2-step and timing retard, triggerable from the trans-brake input
- Dominator-style 4-bolt air cleaner flange
- -8 AN fuel inlets
- Full-color touchscreen for setup, tuning, and gauge display
- Simple calibration wizard — no laptop required
- Self-tuning ECU that learns and adjusts without deep tuning experience
- Bosch LSU 4.9 wideband O2 sensor for real-time fuel map learning
- Built-in MAP sensor rated at 2.5 BAR
- Designed for at-home installation with Holley's manuals and video support
- Compatible with HyperSpark, air cleaners, and digital dash accessories
Specifications:
- Injectors: (8) 100 lb/hr
- Throttle Plate: 2.125", 1440 CFM
- HP Support: 800-1500 HP naturally aspirated / 800-1250 HP forced induction
- Air Cleaner Flange: Dominator-style, 4-bolt
- Fuel Inlets: -8 AN
- MAP Sensor: Integrated, 2.5 BAR
- O2 Sensor: Bosch LSU 4.9 wideband
- Controller: 3.5" full-color LCD touchscreen included
- Tuning Cable: USB-to-CAN included
- Software: Free downloadable Sniper EFI software
- Finish: Polished
- Part Number: 550-841
Designed for dragster, pro-street, and other aggressive race applications, with multiple input/output channels available for sensors, switches, and external relays.
FAQ
What horsepower range does the Stealth 4500 support?
It supports 800-1500 HP on naturally aspirated engines or up to 1250 HP with forced induction.
Do I need a laptop to tune this system?
No. The Stealth 4500 uses a self-tuning ECU with a simple calibration wizard on its built-in 3.5" touchscreen — no laptop or prior tuning experience is required.
What size throttle plate does it use?
It uses a 2.125" throttle plate flowing 1440 CFM.
Does it support forced induction?
Yes, it's compatible with both draw-through and blow-through forced induction applications, supporting up to 1250 HP.
What's included for tuning and monitoring?
The kit includes a full-color touchscreen controller, a USB-to-CAN tuning cable, a Bosch LSU 4.9 wideband O2 sensor, and free downloadable Sniper EFI software.
Can I add launch control?
Yes, it offers programmable launch control via 2-step and timing retard, which can be triggered from the trans-brake input.