Fuelab 51506-1-L-E Series EFI Adjustable Fuel Pressure Regulator Large Seat - 515 Black

The Fuelab 515 Series Adjustable Fuel Pressure Regulator (PN 51506-1-L-E) is an EFI-spec, large-seat regulator engineered for performance fuel injection systems requiring precise pressure control. Designed with both performance and installation flexibility in mind, the 515 Series accepts port-style and non-port-style union fittings without interference. The -E configuration covers a 25–90 PSI adjustment range, making it ideal for a wide range of EFI applications. The regulator features a black anodized billet aluminum body (anodized per military specification MIL-A-8625, Type II) and a bottom-mounted -6AN return port for clean plumbing layouts.

Key Features:

• EFI pressure range: 25–90 PSI adjustable with fine-thread pitch adjustment screw for precise tuning
• Large seat design for increased flow capacity — rated at 1.25 GPM
• Two -6AN inlet ports and one -6AN return port (bottom-mounted); compatible with port-style and non-port-style union fittings
• Fuel compatibility: gasoline, diesel, methanol, and ethanol
• Billet aluminum construction with black anodize per MIL-A-8625, Type II for corrosion resistance
• 1/8 NPT gauge port with plug for an external fuel pressure gauge
• 1/8 NPT pressure reference port with barbed fitting for MAP sensor referencing
• Includes versatile mounting bracket with stainless steel hardware
• Backed by a 2-year limited warranty

The Fuelab 51506-1-L-E is sold individually and suits high-demand EFI builds where accurate, stable fuel pressure is critical. The 515 Series line also supports configurations from 1 PSI (carbureted) up to 125 PSI, offering a regulator solution for virtually any fuel system application.