Precision Oil Restrictor (-4AN) for Garrett Ball Bearing ...
Precision Turbo's Oil Feed Restrictor fitting with -4 AN Male Flare x 7/16-24 thread and a 0.035' orifice. This thread is designed to thread directly into Garrett Turbos. Turbo oil restrictors are often a necessity for ball bearing turbos to restrict the flow and pressure of the oil reaching the CHRA. By reducing this excess windage on the bearing you can achieve optimal boost response ...