Pub science NA-T oil lines, lol.

Hey guys, quick question, I was having a chat with some buddies who are also into cars last night down the pub and we got talking about NA-T conversions, anyway somebody mentioned how you have to either remove the engine or drop the subframe to install oil feed/drain for the turbo, at which point one guy asks: "why can't you just fit an oil filter relocation kit, and run the return line through the turbo?".

Now I know that must be a bad idea because if it wasn't then everyone would do that, but I have no idea WHY it's a bad idea and neither did anyone else, we just settled on the fact it must be wrong otherwise nobody would go to the trouble of doing it the "normal" way.

Anyone care to fill me in so I can explain it to the guys?

Thanks.

*EDIT*

Just realised my avatar has passed away since my last post, sad times

Try it and you'll fill the engine bay with hot oil and probably set fire to the car (if it lasts long enough for things to get hot).

There is far to much flow from the oil pump to pass the full flow through the turbo bearing housing so something would let go. Some turbo manufacturers require that a restrictor is fitted into the oil feed to limit the flow if you are using a large bore feed line.

That makes a lot of sense, thanks

On that logic, route the return to a catch can and stop every fifty feet and refill the engine from the catch can.....