is there a big size difference between a water cooled turbo and a non water cooled one? i have a t3/t4 that is NOT water cooled and my friend has a t3/t4 that IS watercooled and our oil feed line doesnt have the same size. Mine is a little bigger than his. what size oil feed line do i need? (the one that sticks in the turbo) its a T3 stg. III turbine T4 .54 a/r? i have no idea if i wrote that down right but for some reason i recieved a turbo with a blue back plate..even though i didnt order it that way!

 

Use a -3 or -4. I have an oil only but I think my turbo is getting too much oil with the -4 line and may swap it out after I work with the oil return a bit.