How to Make your own oil restrictor for journal bearing (non-BB) turbos

I recently installed a new T04b Garrett turbo on my 2G. I am feeding the turbo with a 4AN stainless braided line coming off of the oil filter housing. The CHRA of this (and many other) Garrett turbo likes the oil pressure in the inlet to be between 30-50 PSI. I was worried that I might be over-oiling or over-pressurizing it which would eventually cause premature failure. That prompted me to begin searching for a restrictor to place inline with the turbo's inlet and the oil feed line. My search came up short. I then decided to make my own kit.....
Parts include:
(1) Aeroquip adapter fitting- NPT to AN - (I used -04 AN to 1/4" NPT. NPT side may vary per application.)
(1) Nitrous Jet - size is personal preference. I used .078.

The flare angle on the fitting and the nitrous jet are both 37*. Basically what you need to do is turn-down the fitting end until it has no tapper and it is flat.


1st step - You will need access to a lathe. Turn it down far enough until there is no longer a flared angle on the end. Clean up all edges - no burs.

2nd step - slide the nitorus jet into the hole. The seat of the jet should be flat with the surface of the machined area.

And you are done. Basically, you have the same fitting, with the same 37* end, but now it will restrict flow to whatever size jet you are using. I will get more pictures of this restrictor on the turbo.....