TheRealSy90

I know the factory S13 hoses off the vc T fitting have a restrictor "Pill" inside of them.
Do the S15 hoses have any restrictor? The rear vc to crank hose and the front vc to turbo intake hose.

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Kingtal0n

All engines requires some restriction to fresh air inlet or the pcv will never reduce the pressure inside a crankcase.

In chemistry there is a condition known as dynamic equilibrium, which is where the pressure differential inside a container is made up for by the evaporation of liquid molecules to a gas phase. For example if a cylinder is de-compressed by a piston (larger volume from small volume) there will be a pressure drop, but if the cylinder contains liquid phase solution, some of that liquid can evaporate to restore the pressure. This is called dynamic equilibrium. There is a great picture of this example in a typical chemistry book.

The goal of PCV is to take advantage of the partial pressures of liquid phase molecules, as in the dynamic equilibrium condition, within a set pressure drop (difference) as a steady state, thereby pulling the lighter liquid phase molecules (oil is heavy and stays as a liquid, while partially burnt gasoline and unburnt gasoline is light compared to oil so it can become a gas or stay as a gas) into the crankcase gas/air, so it can be removed easily by the PCV system, constantly. thus maintaining the oil quality. To put this another way, the flow rate of the pcv system by itself is not enough to pull contaminants from engine oil and remove them; there MUST be some pressure drop in the crankcase to pull light molecules from engine oil, taking them from liquid to gas state. Simply hooking a pcv valve to the intake manifold and connecting the other end of the crankcase to the air filter tract is NOT enough unless the orifice has been adjusted to accommodate the flow rate and volume of the crankcase pcv system to give the necessary drop in pressure.

The pressure drop also assists the piston ring seal, thereby reducing blow-by, and improving compression (tightness) of the sealing rings. That is why PCV is ultimately the most important system on an engine to be functioning properly; and why I go through great lengths to stress the importance of measuring it when you modify the intake filter or duct work. Without a pressure drop, the piston rings performance will suffer, the oil quality will suffer, the engine will deteriorate more or less rapidly depending how poorly the pcv is setup. All the engine's oil seals will suffer when PCV is poorly setup, but oil leaks can be pressure washed and oil seals can be replaced, so that is a secondary concern to the engine internals cleanliness and engine longevity.

Note that in many engines, the "restrictor" is simply an orifice diameter. For example in Chevrolet LS engines the "restriction" is provided by the size of the hose on the valve cover (approx 10mm~) from what I can see visually. Since the hose on the sr20 is huge (20mm~ or more diameter) it needs that restrictor to reduce the orifice diameter to create the pressure drop.

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TheRealSy90

My dog, I didn't need a term paper on fluid dynamics.
I'm asking if there is any factory restrictor in the two oem hoses on the exhaust side of the S14/15 valve cover. I don't have the oem hoses. I know S13 has them.

Care to show me how you personally have measured pressure drop in the sr20 crank case? You say this all the time but i've never seen you actually show how YOU do it.

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slider2828

S14 and S15 don't have that restrictor from crank case to valve cover.

The VC design is slightly different and the air oil separation is built in vs S13 needing that copper plug in the hose and the black box can.

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S14rebuild

Nonono.... dont get him all riled up.... here come 8 paragraph post with no info ull actually need/use

e30gangsta

Lmao this man knows.

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Kingtal0n

1. its not fluid dynamics, its high school chemistry from the entry level CHM1101 book. I Would never post fluid dynamics on an internet forum because nobody can use those PDE easily.
Dynamic equilibrium:

CHM1101 book:



2. It doesn't matter what kind of engine you have, they are all the same requirements designed by the OEM Engineers around the world.
You can measure using any 0-5v 2-Bar Map sensor, exactly the same way you measure intake manifold boost pressure.

So to recap, if you can measure boost pressure, you can measure crankcase pressure. If your ECU lacks the ability (OEM ecu or PFC) You can use Arduino ($22~) with any 2-bar map sensor (0-5v sensor). Since arduino can directly measure voltage, there is no need for resistor/voltage divider as with other resistance based sensors. If you'd like to see how I do it on my Chevrolet engine send a PM and I will give you instructions, videos, pictures, part numbers for all the components I Use to do this, In fact I even have extra Arduinos I can send you one for free.

cured13

I think I'm not the only one that appreciate your kindness and sharing.
Thank you and please post more pics and instruction here.

Ignore all haters.

TheRealSy90

No I want to see your sr20 with perfect crank case pressure.

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PoorMans180SX

This is pretty sweet... Radium has been developing cool parts for our rustbuckets for a while now! Their fuel line clamps and filter kit are dope as well as their fuel hanger!

http://www.radiumauto.com/Catch-Can-...S13-P2031.aspx

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e30gangsta

Pretty steep price, and cumbersome to have to run two catch cans. Neat non the less.

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PoorMans180SX

Necessary unless you delete the PCV valve or have lines running all over the engine bay. Yes, radium stuff is definitely pricey, but oh so nice, hah.

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mr.nismo.

I'm going to use the universal P/N for my PCV side (my bay is pretty packed). But I hadn't realized how compact their cans are.

Sent from my Note 20 Ultra using Tapatalk

slider2828

Wow that is really cool... I wish they had the option to run all the plumbing back to intake housing.... engine always like some extra vacuum under boost

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MPIracing

actually I don't know how to upload a photo on here...lol


been following this thread for years, love it, Here is what I did way back when, I had major issues on the track days with over flowing oil, streets was fine, yet changed the catch can to what you guys developed I only drilled 8 or so holes under the fitting welded in. and now on the track days, I don't have more than a tea spoon of oil in there after the whole day. just going for a new turbo set up now, gxt2867r on the sr, thanks again from the land of Oz!

MPIracing

slider2828

Glad it was helpful!

Just use imgur.com and upload a photo there and copy the picture URL back here... only free way to do it nowadays

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