Oil Restrictor Fitting -4AN x 1/8in NPT

The Oil Restrictor Fitting -4AN x 1/8in NPT from VIBRANT PERFORMANCE is a precision flow-control component designed for turbocharger and supercharger oil feed systems. This fitting restricts oil delivery to the turbo bearing to prevent over-lubrication, bearing damage, and excessive carbon buildup—critical concerns in high-performance engine builds where oil pressure can exceed safe limits. Whether you're upgrading a forced-induction system or servicing an existing turbo installation, this restrictor ensures optimal oil flow rates that protect bearing longevity and maintain engine reliability.

Constructed from black anodized aluminum, this oil restrictor fitting features a hex head design with a dedicated Allen key (hex socket) and stainless steel jets that meter oil flow with precision. The -4AN to 1/8in NPT thread conversion allows seamless integration into existing turbo feed line architectures, accommodating both -4 Autosports Naptune AN-spec hose connections and standard NPT threaded ports. Anodized aluminum resists corrosion and oxidation in high-temperature engine bay environments, while the stainless jets maintain dimensional consistency across thermal cycles, ensuring stable restriction characteristics over the vehicle's service life.

This restrictor benefits street and track enthusiasts running turbocharged or supercharged engines who demand refined oil management without complex external regulators. Installation is straightforward—thread the NPT side into the turbo supply line port and connect the -4AN side to your pressurized oil feed hose using standard AN fittings and hose clamps. Compact dimensions and lightweight construction (0.03 lbs) make it suitable for engine bay installations with space constraints. Compatible with any turbo or supercharger system featuring 1/8in NPT oil supply ports and -4AN feed line infrastructure.