Okay, I am in the middle of getting all my parts for my new turbo, and I am going to be running a Garrett GTX3071r on a worked 3SGTE.
 
I have been reading on garrett's website and they specify the the oilflow into the turbo should be no more than 40-45psi, and for most cars the oil restrictor should be a 0.040",
 
Apparantly too much oil will cause windage in the cartidge and slow the spool as well as leak past the oil seals, then I have also read on the US forum some people run GT35r's all day long for over a year without no restrictors.
 
Has anyone else got a ball bearing turbo on a MR2? What is your setup?

The oil line into the turbocharger is the only restrictor needed. The turbo normally comes with this as well.

I think the oil feed line on my old gt35r kit from KO Racing was 3an if it helps 

The Garrett turbos generally have an in built restrictor.

Use the -3 Teflon braided hose that's also used for exotic fuel and brake lines. It doesn't go hard like the normal nylon.

i have a GT3076. the restrictor is seperate and you will likely need it.
 
sometimes they coke up and seal but i found the oil continued to go through the seal and aside from losing a LOT of oil i coated the entire inside of my intercooler and it came out the BOV.
 
it's worth noting mine did this with a very old oil pump that failed shortly after... if you have decent oil pressure then i imagine it would be worse. 

I might ring Garrett today and get their input on this,
 
I will use a -3 teflon braided line as I have two at home removed from other Garrett's, if I am to run a restrictor I would like to use the largest one possible for good flow, I don't like the idea of accidentally starving the turbo of oil.

I've got a Garrett 2860rs on mine ~10'000km on it, got told they had a restrictor in them so never worried, never had issues with it pushing oil past the seals.