no, YOU can't do that with a Garrett
http://s8.photobucket.com/user/Runtmasterflex/media/http___makeagifcom_media_4-20-2012_QxTCE9.gif.htmlGood message from FP on the subject, and I concur completely.
This has been a very popular subject of late with each market pushing the envelope of what these small displacement motors can do. More often than not when we receive these calls people are convinced that their turbo has failed and will need to be repaired and 99% of them are mistaken. We receive at least 1 turbo a month from a person who is having issues with "blown seals" and we have to give him, the good or bad news depending on your outlook, that the turbo is fine and there is a deeper issue at play here.
First and foremost understand that your turbo does not have seals give it a second to sink in. What people refer to as "seals" are actually gas control rings (see the gif posted below for a visual) and these sit in grooves on the turbine shaft and the compressor side seal plate. These act much like piston rings their main function is not to keep oil in, they are in place to keep pressure from the turbine and compressor housings out of the center cartridge of the turbo. Seeing as how these rings ride in metal grooves there is no way for these to become damaged without a significant amount of shaft play. So the rule of thumb here is if your turbo doesn't have excessive shaft play your "seals" are fine.
So you're asking yourself well if the rings haven't gone bad how could oil get out? Well remember how we likened these gas control rings to that of a piston ring? Well just like a piston ring these have small gaps in them and there are a few reasons how oil can be forced through these gaps into the housings. We'll cover them from simplest to the most complicated in that order. Just to get the ball rolling here is a link to a GIF giving you a visual reference.
http://i8.photobucket.com/albums/a20/Ru ... QxTCE9.gif Your drain tube is not up to par.
What we mean by this is that normally most TC's we sell have about an 1/2" orifice to allow oil to drain out of the bearing housing. This is 100% gravity fed and has no pressure to push it through. So any sort of obstruction can throw the balance off and allow oil to back up inside the bearing housing and seep through the gas control rings. It could be something as simple as a kink, too much RTV, or just inferior tubing that is starting to collapse internally. A less common cause and is usually a problem on cars that weren't originally turbocharged is that the drain flange on the oil pan is below the fill level.
You're feeding the turbo too much.
This particular issue can be a little harder to diagnose as it usually requires a oil pressure gauge metering from the same place the turbo is feeding from. Most of the turbos operate under the assumption that they will see max pressure of 70/80psi. The restrictors we sell for our ball bearing units operate under this understanding as well so if you're running super high oil pressure a different restrictor might be required. If the car is supplying more than that there is a chance you can over run the turbos drain ability and will cause the bearing housing to back up and seep oil out of the gas control rings.
Your PCV system is not up to par.
This is a tricky one and is by far the hardest to diagnose but fixing it is relatively easy. Your stock system is typically a two vacuum system on vacuum pulled through the PCV valve on the valve cover through the manifold and another pulled off the valve cover to the intake of the turbocharger. The one of the PCV valve is used to control PCV during idle and cruising and the other is used under boost. A lot of people making 400+WHP ignore their crankcase or make it worse by removing these vacuum sources and this is a big mistake.
The fact is at stock power and stock motor a lot of people are able to skirt by without any issues and never know that they are leaving power on the table by not sorting it properly. However a lot of people just band aid the issue when they see their dipstick come out they put a vent there. Or they remove the vacuum and run a catch can in line vented through a mesh filter. These do not alleviate crankcase pressure they just give it more room to fill and possibly a little less resistance in certain places. If you were to measure the pressure in the crankcase you would see you still have some and it being in there is not helping you any.
The proper way to run this setup if the stock setup is no longer working for you is to enlarge the diameter of the hoses connecting to your system. Personally on my own car I ran 2 -10 lines via fittings welded to my valve cover to a catch can then another -10 line from the catch can to the intake. This allows for greater volume through the lines and still pulls a vacuum to ensure that all crankcase pressure is being alleviated. Is this over kill for a 400WHP car? Maybe but it guarantees that you'll never have to tinker with the PCV system again.
We also have people convince themselves it's the turbo from swapping from on turbo that does not smoke to one that does. Unless it's the same exact model of turbo charger this is not a valid test. Each turbo has a different bearing housing design some with giant valleys for the oil return like the Journal Bearing Red/Green/Black because they require a lot of oil to be properly lubricated. Some have much smaller cavities like the their ball bearing counter parts because they require much less oil to operate. When talking about this little of pressure 1psi or more it doesn't take much one way or another to either not have an issue or to have an issue with oil being forced out.
So in conclusion if your turbo is smoking and the wheels aren't clanking off the housings it's safe to assume that your issue lies elsewhere.
(I guess there is some truth in every joke 
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