1/16NPT Male to 4AN Male Vac/Boost Reference

The 1/16NPT Male to 4AN Male Vac/Boost Reference adapter from REDHORSE PERFORMANCE is a precision fluid-transfer fitting designed for vacuum and boost reference line applications in automotive and motorsports systems. This straight adapter serves as a critical connection point where vacuum or positive pressure signals must be routed from engine sources to boost controllers, fuel pressure regulators, and air suspension systems. The fitting bridges two industry-standard thread types, allowing seamless integration in custom fuel system builds, turbo setups, and performance engine management configurations where reliable reference pressure communication is essential.

Constructed from stainless steel with a natural finish, this adapter combines corrosion resistance with durability in under-hood and fuel cell environments. The 1/16 inch NPT (National Pipe Thread) male port connects to metric or imperial threaded reference bosses on engine blocks or manifolds, while the 4AN male outlet accommodates standard AN hose fittings and gauge ports. The straight design minimizes flow turbulence in pressure lines and reduces dead-volume in signal circuits, helping maintain accurate boost or vacuum readings at the control module. Stainless construction ensures the fitting resists fuel vapors, coolant splash, and thermal cycling without degradation or leaking.

This adapter is ideal for tuners, fabricators, and enthusiasts assembling forced-induction systems, custom fuel injection setups, or adjustable suspension platforms that require discrete vacuum or boost measurement. It integrates seamlessly into PCV systems, boost-sensing fuel pressure regulators, and electronic boost controllers where NPT threaded reference ports exist. The compact form factor (2.8 x 1.1 x 3.9 inches) fits tight engine bay installations, while the light weight (0.055 lbs) adds negligible mass to the system. Verify NPT thread compatibility on your engine or manifold reference port before installation, and use PTFE tape or liquid thread sealant on the NPT male end for leak-free operation.