Turbo feed

Hey guys, I am at the point I need to assemble my turbo feed hose, I have searched alot and can't find my answer. I have found where alot of guys seem to be using -4, but my factory hard line is nearly identical to -6.

I have alot of -6 hose and fittings but a slimmer selection for the -4. Is there a certain reason guys switch to -4 which is nearly half that of the factory hard line? I have searched and can only come up with what guys are using but I also have to ask why because less oil flow through a journal style turbo just seems wrong to me.

i've had the same concerns yet there are thousands of turbos happily spinning with aftermarket -4 feed lines, including my own van.... that being said if you can come up with a -6 line from your parts bin why not ?

what turbo are you planning on using? I have put many turbos in many places they didnt belong. I've put car turbos on tractors, truck turbos on cars etc. I always use -4 feed lines. Your mileage may vary.
IMO, the drain line sizing and design is quite a bit more important than the feed line (so long as your feed actually gets the oil to the turbo).

The OE oil feed pipe over to the Turbo is larger inside, however, the hole in the fitting on the center of Turbo CHAR is small like the #4 braided hose.....

Here are some pics to compare.

The pic below is of the VNT 15 and OE oil feed pipe. The banjo end is used to show size comparison of the holes...



The pic below compares the braided hose to the fitting on the VNT 15



The pic below compares the OE pipe to the braided hose, #4



The pic below compares the banjo end of the two pipes.



Considering the oil holes in the two shaft bushings are much smaller, I see no problem. The TDI engine in my Vanagon has about 55 psi oil pressure at 2500 RPMs and up at operating temp. Idle oil pressure is at or above 25 psi with fully warmed up engine.