So like the topic asks...
Does anyone think a -3AN feed line for the turbo is too small? Please give reason as to why you think it might be too small as well.
I am having a bunch of problems with a smoking turbo. My seals are pretty much shot on the turbo which is causing this. But the turbo is brand new, well about 6000 miles on it. But still, it shouldn't be bad yet. Anyhow, there is a ton of shaft play and the bearing is certaintly damaged.

Any advice?

Oh, I have a -12AN drain line. THe i.d. on the 1/2" drain fittings is 7/16" if you guys are curious about that. And the drain is a straight as possible, although not perfectly straight.

Thanks!

What type and brand of turbo do you have? Some requre oil pressure to be around 30-40 psi going into the turbo and our cars usually run about 60-70 psi when fully warmed up. Only thing I can think of is to use an oil restrictor on the oil feed. I am using one of those and a -4 AN oil feed line and am having no problems.

You will probably have to get your turbo rebuilt or buy a new one if there is substantial shaft-play and the oil seals are gone.

And -12 AN oil drain? -10 is what the average people go with.

-3 is fine.

Thanks for the feedback.

When you say you used an oil restrictor... what size (approximately) was the hole?

Do you guys think that a 7/16" drain is large enough as well?

Originally posted by bzoss
Thanks for the feedback. When you say you used an oil restrictor... what size (approximately) was the hole? Do you guys think that a 7/16" drain is large enough as well?

ATP sells .065" oil restrictors for T3 CHRAs. Most returns i've seen are 1/2" or so. I use -10 myself and have never had any problem.

Is it possible that this restrictor is too much? I have a T3 with the 360 degree thrust bearing. Recently I put a .030" nitrous jet in line with the supply to act as a restrictor because I thought that I was 'overpressurizing' my turbo with oil causing oil to spew past the seals.
I believe that this ultimately is what wiped my turbo's seals and bearing.

Basically the T3's are already restriced on the inside of the cartridge/bearing housing, and I am not sure that it is a good idea to ristrict the oil at all before this.

Any further thoughts?

I think your restrictor is a little too small. Per the following source, it appears as though 0.078" or around that is a good restrictor size for Garrett turbos that require it:

http://www.dsmtuners.com/forums/showthread.php?t=171317

Many people get away with just drilling out an oil inlet flange to their desired specifications. While over-lubrication can be a serious problem, for standard journal bearing turbos, under-lubrications seems much more harmful.

Ball bearing turbos are the ones you'd want to use such a small restrictor for...