Holley EFI Terminator X Max Stealth 4150 – GM LS Engines

Holley EFI Terminator X Max Stealth 4150 – GM LS Engines

The Holley EFI Terminator X Max Stealth 4150 – GM LS Engines is a high-performance EFI system designed to replace your carburetor with a clean, stealthy setup that supports up to 650 HP naturally aspirated or 600 HP forced induction on GM LS engines. It features advanced self-learning fuel maps, integrated ignition timing control, and plug-and-play transmission control for popular GM automatics, making it ideal for enthusiasts seeking reliable power and drivability improvements.

Key Features

• (4) 100 lb./hr. fuel injectors supporting up to 650 HP naturally aspirated or 600 HP forced induction
• 3.5” LCD handheld touchscreen for setup, tuning, and gauge displays—no laptop required
• Self-tuning fuel maps with Bosch LSU 4.9 wideband O2 sensor for real-time adjustments
• Integrated ignition timing control improves idle stability and wide-open throttle performance
• Plug-and-play transmission control for GM 4L60, 4L80, TH350/400, 200R4/700R4 transmissions
• Stealth wiring exits below rear fuel injector cover for a clean installation
• Bolt-on 4150 flange fits many factory intake manifolds with air cleaner locator provisions
• Supports boost, nitrous, knock retard, and advanced sensor inputs and outputs

Fitment

• GM LS engines with 24x or 58x crank reluctor wheels
• Universal 4150 squarebore flange intake manifolds
• Compatible with GM 4L60E and 4L80E automatic transmissions

Note: Requires an external fuel pressure regulator set to 58.5 PSI (Holley P/N 12-886 or equivalent). Distributor, fuel pump, fuel hose, and mounting hardware are not included. Verify compatibility with your vehicle and supporting components before ordering.