Ball Bearing Garret "r" Series Turbos And Oil Feed Restriction

[Chris Wilson]

RB26 engine, Tomei oil pump, standard out of the box pressure relief valve shims, and two new Garrett GT2860-10 turbos. Stock oil feed lines to the turbos. Do they need any additional restriction? Here in the UK I have asked 5 people, all well versed in either Skylines or Garrett agents, and have had 5 different answers... I am told by 2 of them that the ball bearing turbos have restrictors inside them, after the oil feed female port, and invisible externally. Others say the Tomei pump delivers so much pressure a restrictor in each Banjo bolt on turbo female fittings of 1mm is vital. Others say no restriction is needed. Another says 1.5mm.... Real world experiences please

[paulR32gtr]

I have installed both -7's and HKS GT-SS's (based on R series) and they both have oil restrictors built in. You can actually see them by looking in the oil inlet.

Not sure about operation with the Tomei oil pump though.