Fitting size:
-4AN
If you have ever needed to restrict fluid flow in a -3 or -4 line, Speedflow now has the answer!
Check out these 399 Series Restrictor Inserts that simply slide into a -3 or -4 hose end and held in place by the adapter screwing into the hose end.
The restrictor has a 1mm ID hole making it perfect for oil restrictors on Turbos.
Commonly used in ball bearing turbo oil feeds when oil pressure will exceed the recommended 40-45psi pressure rating such as Garrett, BorgWarner EFR, Mitsubishi, GReddy, Trust, HKS, Tomei, Precision, Holset etc
