I have a T3/T4 turbo with a -3an line and i was wondering if i should run a restrictor.

 

no if it's non ball bearing.

 

Typically no. but you want to check your oil pressure at the feed line first before that is definate. I've had a few in which under normal circumstances, no restrictor would be required only to find out that the oil pressure was just blowing past the seal rings on a brand new unit, and one is required. (this happened when all other factors of the setup were correct.)

Try it and see. check oil pressure.

 

Just for my knowledge, how much pressure do you want to see at the line? And what would be the best way to go about checking it? hook up a pressure gauge to the end of it?

 

Yes. about 35-50psi of oil pressure. If its a little over or under, that's no problem, but it should not be over 70psi of oil pressure at WOT.

 

no other way to check unless i buy a oil pressure gauge?

 

put it together and try it out. you won't destroy it immediately, but you have to see if you don't have a pressure gauge.

 

is it better to be safe to just get a restrictor?

 

I wouldn't say that.. Until you check. If you need one, you don't one any smaller than 80 thousandths.

Again, 9 times out of 10, it is not needed. but you might be a rare one. It is better to be unrestricted and put one on later, than to be restricted with the wrong size and cause bluing on the shaft, ruining the turbo.