I didn't get that, his pic, and what I did read, mentioned the turbo inlet for the vacuum source. Same here, I agree on the oil. I personally won't be doing pcv, but the info is actually good if someone wants to do it, it's just not the best/only way imo.

 

After say 150k to 200k miles there is barely any oil near or on the turbo, none gets past the wheel as long as crankcase pressure is kept low enough to diminish crankcase gas density which is related to oil droplet size formation and number of oil droplets suspended. Low crankcase pressure just as with a vacuum pump has an oil droplet prevention effect, it helps oil return to the oil pan and frees up the oil drain of the turbo preventing oil from passing the turbo's seals.

I have to manually add WD40 to lubricate whenever I perform maintenance to keep it lubricated. Oil helps to seal the wheel within the center of it's housing exactly as oil molecules act to take up space between a piston ring and irregularities of the surface of a cylinder wall, and is beneficial to prevent oxidative surface stress as well. Borg Warner recommends oil the turbo compressor stage. And even if oil could pass it wouldn't be able to get through the intercooler or up the charge pipes lol. All turbo engines use the same OEM pcv system. All of them depend on routine maintenance of course. After 20k to 30k Miles I remove the intake and wipe out the inside with a paper towel and inspect the compressor wheel. By using the angle of the intake pipe you can force high molecular weight debris to become trapped before it can reach the compressor wheel. The human body uses the same feature at the oropharynx where an peyers patch which is a white blood cell conglomeration takes advantage of the sharp 90* turn air makes after it enters the mouth to flow into the trachea.

There is alot you can learn from the human body which applies to combustion engines, biology and chemistry is just as important as engineering. In the courses I am a teaching assistant for I always cover the chemistry and biology aspects which engineering books often fail to even mention such as the relationship of crystalline lattice covalent bonds within mechanical structures to which force and stress is applied. The book covers beam bending and failure but never mentions why and how failure occurs in terms of the atomic linkages. Something like decaying structures and heat related deformation based stress can be explained using a direct mathematical approach or via statistical relationship of internal bond chemistry.

 

The oil were avoiding is blown from the valve cover as the top end is oiled regardless of crankcase pressure.

 

Thats a myth. Crankcase pressure is directly related to oil droplet formation and gas density within the crankcase. Vacuum pumps pull oil off of engine parts and increase oil return to the oil pan. If I disconnect my breather hose from turbo inlet or remove the air filter the crankcase starts blowing oil all over the place. With a pressure drop on the crankcase no oil comes out of the valve cover.

 

To understand the difference between pulling and pushing takes chemistry and engineering.
In terms of chemistry we look at diffusion of a gas. At rest, gas molecules are moving 500 to 1000miles per hour, very fast. And yet we consider their net velocity to be zero, v=0. Consider a tire for a moment, is the gas inside going anywhere? No the V=0, gas stays inside the tire for the most part. Nevertheless the gas molecules are moving 1000mph inside the tire and colliding with the walls of the tire, causing it to remain inflated, seeking crevices of the tire. Some do escape but most remain inside.

When blow-by gas enters the crankcase it begins to diffuse from an area of high concentration to low concentration, in all directions at once, like air inside a tire. Velocity is close to zero because it moves every direction simultaneously, even though the gas is diffusing, passive diffusion is not organized gas flow velocity, the net velocity is zero. We call this condition PRESSURE. Pressure is a scalar unit, it has no direction associated with pressure. Pressure is a gas moving all directions at the same time. Thus, pressure is rising inside the crankcase and when the pressure begins to rise, gas density is increased. PV=nRT, we increase pressure we increase mass and therefore density at the same volume. This increase in pressure with no direction allows blow-by gas to diffuse into engine oil, and attack oil seals. Just like gas from inside the tire can escape so does blow-by and engine oil begin to escape through engine seals because of the pressure scalar. Diffusing of gas into engine oil allows the blow-by gas to circulate in engine oil and form deposits around the engine. Blow-by contains hydrocarbon partially reacted radicals and conglomerates which form deposits and disrupt oil flow, increasing engine wear as they settle out in various crevices. The size of carbon deposit molecules initially is just 100 to 800picometers, less than 1 nanometer, it can find small regions of bearing and oil flow orifices to stick and gradually accumulate leading to engine wear and catastrophic failure eventually once enough deposits collect. Similar to athersclerosis within a human body where a small deposit gradually accumulates more and more blocking an arteriole or capillary eventually or at least restricting flow. We've all seen stuck lifters with carbon deposits restricted oil flow, camshaft oil tubes clogged and bearings with specific wear streaks due to accumulate deposits & resulting trash which prevent a proper oil film from forming or directly damage the bearing by taking up the space where oil should be or limiting oil film thickness. Sometimes the trash comes from the air filter and sometimes it is related to the carbon deposits formed from blow-by: whats the difference? A pollen molecule for example mostly contains carbons and metals, it will partially react in combustion chamber and form a similar mass of sticky partially reacted hydrocarbon conglomerates as gasoline will, just more of them. Thus, poor air filtration and poor PCV control have the same resulting affects on blow-by gas and crankcase deposit formation, only the air debris tends to form much larger, stickier carbon deposits and damages the delicate ring seal and bearing surfaces more easily and in greater quantity than gasoline fragments which tend to be much smaller and more easily controlled by quality oil.

As pressure scalar unit rises inside the crankcase we have to start looking at engineering to see what effects occur inside the crankcase. Pressure in the crankcase will cause a few issues with ring sealing and create more blow-by. Pressure is forcing the piston ring up, and this causes early ring switching and ring flutter conditions depending on the engine and ring design. Pressure is reducing ring tension forces and allowing more blow-by to slip past the rings. These combined effects tell us that high crankcase pressure causes even higher crankcase pressure in a feedback loop where pressure on the rings will reduce ring tension and cause more blow-by which raises pressure and creates more pressure on the rings which causes even less tension and more blow-by and so forth until some maximum. This will raise crankcase gas density and increase oil droplet suspension in the crankcase gas, so any gas exiting contains much more oil and more blow-by gas. The energy to organize the gas as it is forced to exit some breather is coming from blow-by entering the crankcase, the blow-by requires more energy to exit the piston ring pack than it would otherwise. These effects can all be illustrated easily with two common examples. First, a vacuum pump allows the use of low tension piston rings, because high crankcase vacuum increases ring tension effects and pulls blow-by out of the piston ring pack, the vacuum pump supplies the energy to remove the blow-by gas and help force the ring against the cylinder wall. Second, when a piston is broken , literally apiece of piston is missing, the crankcase pressure will rise dramatically and oil will start blowing out of the crankcase at a high rate, allowing us to see the influence of crankcase pressure on oil blowing out effects.

So far this is mostly chemistry. We have to move onto the engineering aspect to understand how crankcase gas pressure, velocity, kinetic energy and component gas flow changes the situation dramatically.
With a vacuum supplied to the crankcase, as with a vacuum pump or via turbocharger-air filter suction, or in a naturally aspirated engine between the air filter and throttle valve pressure drop, this energy supplied to the crankcase imparts an organizational affect on blow-by gas, scavenging the blow-by gas before it can begin to passively diffuse. In other words energy supplied by the vacuum pump/turbo/piston suction is used to organize crankcase gas and impart a combined velocity component so V no longer equals to zero inside the crankcase, now the gas molecules are all forced to organize and flow in a specific singular direction: the exit. This preventing blow-by from accumulating in the crankcase and interacting with engine oil. This also preventing oil droplet formation and oil droplet suspension inside the crankcase gas, keeping the oil out of the removed gas which is then passed to the vacuum pump or turbo or throttle valve. Blow-by contains mostly H2O and CO2 which is harmless. With a reasonable crankcase vacuum the piston ring features are protected, preventing early ring switching, ring flutter affects, which reduces the blow-by gas and hydrocarbon components. With a crankcase vacuum present the oil droplet formation and oil suspension is reduced allowing oil to return to the oil pan instead of being ejects from the crankcase as in the broken piston example.

All OEM engines whether turbo or NA include some form of OEM pcv pressure drop for idle/cruise/WOT which can maintain at least 0.5" to 3" Hg for all conditions to achieve these necessary longevity and oil reducing / blowby reducing effects. The issue most people face is they fail to measure crankcase pressure and make changes to the PCV system such as air filter adjustments which negatively influence crankcase pressure and cause oil to blow from the engine, as if a piston were broken. There is no difference between oil blowing out due to broken piston and oil blowing out due to uncontrolled crankcase pressure for any other reason.

 

So.... an oil droplet passing a vacuum source won't get sucked into it? It happens on LS motors that are oem. Oil under the baffle getting sucked out the pcv.

Anyway I like the size of the turbo...........

 

1. Oil droplet is not to be confused with oil gas state. Oil droplets can be 10uM For example which is 10000nM. Whereas an oil molecule as a gas state is 200 to 800pM or 0.2 to 0.8nM , around 1/10000th the size of some smallest droplet of oil.
Pressure determines the force of collision between gas molecules. High pressure allows more oil molecules to smash together cohesive forces hold it together and create larger droplets the longer it is suspended. High pressure also increases collision rate which prevents the action of gravity from returning oil to the oil pan in wet and dry sump engines. An oil droplet falling in a vacuum falls much more quickly than an oil droplet falling in a dense high pressure environment.


2. The OEM engine is configured to supply gas state (800pM) oil residue molecules to the OEM turbocharger and OEM throttle valve at some rate which protects and lubricates those parts. Without lubrication the throttle valve may stick and become worn, it depends on the air quality and environment the vehicle is operated in. The OEM assumes the worst case environment (Dry and harsh) so the oil film supply is typically a slight excess. Without lubrication the turbo/throttle valve materials will oxidize more quickly. Metal requires oil film lubrication as oxidation protection and lubrication, all metal requires this, no matter where or what, oxygen and abrasive substances will attack metal materials and the only way to protect them generally is with an oil film.

So yes, every 50k to 100k miles I find and wipe out a slight oil residue from the back of intake pipe. I run my finger through it here in this video after 25k miles during the camshaft swap, see I can leave a streak from my finger but when I turn my finger towards the camera there is no oil on my gloved finger.

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The oil streak is caused by accumulation of gas state oil molecules (NOT oil droplets) which collect as a dry film within the rough surface feature of the intake pipe, helping to trap debris. It is a useful additional air filtration aspect if pulled off well using the bend in a tube as a collection duct. OEM turbo ducts often contain convolutions and similar bends to help trap debris and isolate oil molecules from air in case the owner never cleans the tube.

Here is the compressor wheel
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Spotless. I had to add oil manually, I Put motor oil on the (rusty ass) nut hardware and WD40'd the rest of the compressor stage. The only reason it rusted in the first place was because there is no warning in the box when you buy a brand new BW turbo to oil it so it immediately rusted once on the car before I even realized what was happening. Why they supply a super dry exposed ferrous metal hardware I don't understand but now I warn people.

Borg Warner engineer says oil the damn thing. If PCV is done properly it won't spray enough oil onto the compressor stage at all you will need to manually oil it yourself.

 

so now that I have the turbo, how do I calculate what size wastegate and BOV that I need? I believe BOV sizing can be somewhat location-dependent? But even so, is there a cant-miss size?

 

The smaller the gate, the easier it will want to produce higher boost pressure. Use a tiny gate if you want super high boost pressure. Use a giant gate if you want to use low boost pressure sometimes. A large gate can still make high boost its just more difficult to control. It depends on your boost control strategy. Using a 4-port solenoid, a quality controller and a proper internal spring the large gate can usually provide high boost pressure without issue.
I always go for the large gate because I'd rather not have boost creep condition with the gate fully open. Bigger is better unless you know what you are doing and have done this sort of thing before.

A bypass needs installed as close to the turbo as possible. Some turbos come with integrated blow-off to give you an idea of how close, it should be right on the housing if possible. It needs to be close to the compressor for two reasons. One is because the less volume between bypass and compressor the faster the pressure can drop between them and the more effective the bypass will become. Two is you don't want to load the intercooler by releasing air that you've intercooled, it is thermodynamically wasteful and kills intercooler efficiency, the air that is cooled raises intercooler temperature and you just throw it away. Garbage

 

Dual 40s or a single 60. Whatever is easier for you to fit.

 

Just thought I'd post a quick update -- I still dont have the turbo installed, but I did make it down the quarter mile at Dragway 42 last weekend with a N/A setup.

 

Good numbers, for the slow 60 ft.
That glide got a brake in it?

 

Yeah, first car I've had with a t-brake. I was using the launch control in my MS3 for my 2-step. But I was pretty happy for my first two passes ever in this car.

 

Figured I would post a little update.. much progress has been made! Should be ready to hit the dyno in another week or two!

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Took my first turbo test drive yesterday. Nothing exciting, I still have issues to work out, but it runs!

 

Got my first real passes in at the dragstrip with this setup and I wasn't disappointed! Still have a bunch of chassis work to do, but this was nice payback for all the work I've put into this. I appreciate the input you guys have given over the past couple years.

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Here's the 10.55 pass,