SR Owners... More HP Easy Mod... Catch Can Setup

[quickdiversion]

it doesn't pour in, it kind puffs in and its not really much smoke, just light wisps. might be worth doing that though, the one way check valve.

[JDMgravy.]

Apologies for the bump guys, but thought theres plenty of info on here already rather than start a new thread.

What do people think of this setup?


Looks like everything is routed to a catch can, then back into the inlet post AFM. Bit odd to have the crank breather connected to a can then back in via intake? Most of the oil in the breather system is coming from crankcase no?

Also wen drilling the rear of the valve cover to weld on a fitting, what type of AN fittings are people using exactly and how do you avoid filling baffles with metal shavings??

[EsChassisLove]

That set up seems....wrong. To me.

It needs a PCV valve, and with that there needs to be a catch can on it also. The PCV valve gets more oil/vaper into your intake and combustion chamber than the other side.

Line-->catch can-->PCV-->intake manifold. PCV is on the catch can so that the can itself cannot get pressurized under boost.


It needs a 3rd fitting on the valve cover to run to the block, then the front line stays how it is.

Use a -12 for a 3rd fitting to the block. Mine is set up like this, except its to a breather filter and I have a 3rd fitting. I am going back to PCV system and hooked to the intake.

As far as the 3rd fitting goes, take the valve cover off to do it. Then clean it out. I've seen people put it on the side, and on the top. I don't know if it makes a difference but mine is on the side. The only difference I can think of it making is on top, it is above a baffle, so more area for oil to catch onto, and you don't have to worry about hitting moving parts.

[EsChassisLove]

Looks like a great setup for WOT, plenty of points to evacuate blow by. But nothing to help at idle.

[Kingtal0n]

Originally Posted by JDMgravy.

What do people think of this setup?


Looks like everything is routed to a catch can, then back into the inlet post AFM. Bit odd to have the crank breather connected to a can then back in via intake? Most of the oil in the breather system is coming from crankcase no?

Also wen drilling the rear of the valve cover to weld on a fitting, what type of AN fittings are people using exactly and how do you avoid filling baffles with metal shavings??

Bad. It needs a vacuum source.

[Def]

It goes to the intake tube. Going to a vacuum source (for low load evacuation) is for grocery getters, not for engines that get pushed.

[EsChassisLove]

Originally Posted by Def

It goes to the intake tube. Going to a vacuum source (for low load evacuation) is for grocery getters, not for engines that get pushed.

Still needs it. You will still spend a lot of time in vacuum if you track it.

[Kingtal0n]

Originally Posted by Def

It goes to the intake tube. Going to a vacuum source (for low load evacuation) is for grocery getters, not for engines that get pushed.

Ill bet you never put a gauge on the inlet tube for a turbocharger. There is nothing happening there, and barely anything during wide open throttle.

All engines need a vacuum source for pcv. There no good reason not to have one. It keeps the oil cleaner, and improves engine efficiency by lowering blow-by during off boost situations.

[EsChassisLove]

Nothing happening at the inlet of a turbo?

My GTX tries to suck my hand in at 1psi....that's not nothing lol

[Kingtal0n]

Originally Posted by EsChassisLove

Nothing happening at the inlet of a turbo?

My GTX tries to suck my hand in at 1psi....that's not nothing lol

The engine is trying to breath when the car is running, so you put your entire hand over the inlet of course its going to feel that way. You can stop the turbo from spinning and it will still try to suck your hand in. Im not saying the turbo doesn't help but the point of reference is not good. Remember that the turbo wont "pull" any airflow that the engine doesn't also ingest. Unless its leaking out somewhere.
The tube is connected via air filter to the atmosphere a short distance away; this automatically means the atmosphere will ALWAYS be "fixing" any actual vacuum you start to build in the tube.


the ONLY way to tell what vacuum you have there is to install a gauge. It doesnt matter how big the tube is; only the pressure inside the tube matters.

And I think you are going to need to measure the vacuum in Inches of water, not mercury or PSI. this would be a great experiment wouldn't it? because I dont think anybodies actually done it. I might try to set this up once and for all. I am thinking a 2L coke bottle filled with water, with marks up a long transparent tube connected into the turbocharger inlet would do the trick.

Lol I might be headed to wal-mart tonight because I am insanely curious.

[EsChassisLove]

My hand was an inch in front of the tube. Not completely blocking it.

Suction is suction. If it didn't work, then it wouldn't be hooked up like that.

[Kingtal0n]

Originally Posted by EsChassisLove

My hand was an inch in front of the tube. Not completely blocking it.

Suction is suction. If it didn't work, then it wouldn't be hooked up like that.

naw man, you got to check the physics. Suction is not suction lol. think of an engine running without a turbocharger. Before the throttle body, there is suction right? Because the engine is breathing. But there is no VACUUM. The engine is pulling air molecules into its intake manifold- past the throttle body, yet before any actual vacuum can be built the air molecules are replaced by the atmosphere.

The same thing happens to the inlet of a turbocharger. The air filter defeats any actual attempt at building a vacuum. You get a SLIGHT pressure drop- but Its got to be less than 2" of vacuum. No ones actually measured it right? So we are guessing until I do an experiment.

The factory uses it because its the ONLY place to get ANY vacuum at all anywhere on a turbocharged engine in boost. Notice the inlet tube is small, the hose is small, the whole thing is lengthy. This would help acquire a slight vacuum during boost, when compared to the atmosphere.

whats funny is, you could always install a more restrictive air filter to get more of a vacuum in the tube during boost. It would hurt power output but improve PCV during boost.

[Sirius]

Hey dudes I was curious what my options are for KA dual cam,, non turbo
i had the valve cover routed to the intake right before the throttle body on my aem intake ,,, How its "supposed to be" and noticed a lot of oil accumulating by my throttle body and i just did not like the idea of oil going into my intake manifold.

sooo i thought it would be a good idea to do what the turbo guys do and just put a little breather filter on my valvecover ,,, so i did this and capped the hole in my intake...
then of course to my surprise it just became messy, oil every where and just looks unprofessional.
not cost effective bec that oil is lost, also makes spots in my driveway,, and also no hp gain .

any tips or advice for a ka guy on how i can solve this problem without spending big money on a catch can that may not even work well? and without getting oil in my intake!? any input will be appreciated.

[KA240SX808]

What's your idea of big money?
A nice Saikou Michi OCC starts at $85, very affordable IMO.
If not look up the Home Depot one using a Air/Water separator for Air Compressors.

[Sirius]

Originally Posted by KA240SX808

What's your idea of big money?
A nice Saikou Michi OCC starts at $85, very affordable IMO.
If not look up the Home Depot one using a Air/Water separator for Air Compressors.

as cheap as possible id prefer to go home made
any links to a write up ?

[EsChassisLove]

I'll post my catch can set up in a little bit. Completely custom and puts a can between the PCV valve and intake also.

[EsChassisLove]

So I got the idea to put a catch can between my PCV and intake because our PCVS system sucks ass and constantly leaks oil into the manifold.

My fresh built engine had a pool of oil in the intake manifold and in my MAP sensor after not even 3000 miles. My can I had between the valve cover and intake tube was bone dry.

So I decided to do both in one. This can is fully custom and fully baffled.

Here's how it routes. As if you were looking at it from the top-

Top left hose-Contains the PCV valve and routes to the intake manifold
Top right hose-to the turbo inlet
Bottom left hose-to the "T" on the VC that is now an AN
Bottom right hose-goes to the original PCVS location on the cover.

The PCV is on the can because during boost you don't want the can to be pressurized. It's already been on the dyno, made a measly 402whp before the rear end gave out. Works like a dream!

[MPIracing]

After year's of playing with can cans, all with no luck after 2/3 laps finally this actually worked for me,

did over 30 laps on a track day and no oil in my can what so ever,

sorry for the bump,,

only thing was my dipstick popped out a bit at first, but just cable tied it down and had no problems after that

[5280VertDET]

Isn't your dipstick popping out a bad sign of vacuum or pressure?

That being said, on my FWD SR20DET my dipstick kept popping because I didn't realize that my intake line was kinked.

PS I've have read this whole thing and my mind still can't really grasp most of whats going on...


EDIT: Fucking GORGEOUS engine bay!

[jr_ss]

If your dipstick is popping out, it's because you have, A. Worn out o-ring on the dip stick or B. Excessive crankcase pressure from bad rings or a failed PCV.

[quickdiversion]

I have not been on this thread for some time.
I have switched from the steel braided line off the exhaust for the e-vac and I am disappointed in myself for not seeing how much of a nightmare that was going to become.

Here is my new e-vac setup.





Once I changed over to this setup the transition from vacuum to boost actually become much faster and the car pulled much harder simply from the great increase in flow.
NOT saying it gained power, but feels stronger.

[PoorMans180SX]

Originally Posted by Kingtal0n

naw man, you got to check the physics. Suction is not suction lol. think of an engine running without a turbocharger. Before the throttle body, there is suction right? Because the engine is breathing. But there is no VACUUM. The engine is pulling air molecules into its intake manifold- past the throttle body, yet before any actual vacuum can be built the air molecules are replaced by the atmosphere.

The same thing happens to the inlet of a turbocharger. The air filter defeats any actual attempt at building a vacuum. You get a SLIGHT pressure drop- but Its got to be less than 2" of vacuum. No ones actually measured it right? So we are guessing until I do an experiment.

The factory uses it because its the ONLY place to get ANY vacuum at all anywhere on a turbocharged engine in boost. Notice the inlet tube is small, the hose is small, the whole thing is lengthy. This would help acquire a slight vacuum during boost, when compared to the atmosphere.

whats funny is, you could always install a more restrictive air filter to get more of a vacuum in the tube during boost. It would hurt power output but improve PCV during boost.

The point is not to build vacuum, as what you're stating is correct. The point is to generate flow. You can then use the intake like a venturi in a carb, and draw air through the system using the intake flow. The closer to the turbo the better essentially, as long as your catch can is able to keep the oil and vapors separated.

This is why exhaust evac works as well, no vacuum, but lots of flow. Again, as long as you can keep oil from disappearing out the exhaust.

You should always use a nozzle with a slit in it for either. Like this:



This guy has tested it. No vacuum, but less crank case pressure with his compound setup.

http://www.dsmtuners.com/forums/cust...on-system.html

[Def]

Originally Posted by Kingtal0n

Ill bet you never put a gauge on the inlet tube for a turbocharger. There is nothing happening there, and barely anything during wide open throttle.

All engines need a vacuum source for pcv. There no good reason not to have one. It keeps the oil cleaner, and improves engine efficiency by lowering blow-by during off boost situations.

No, I didn't put a gauge on it because I can do basic math. The pressure there under boost is far lower than the pressure in the crankcase. If you're smart you also put the fitting at an angle so that the dynamic pressure helps create a lower total pressure in the crankcase evac.

Originally Posted by EsChassisLove

Still needs it. You will still spend a lot of time in vacuum if you track it.

You don't need vacuum in the crankcase when you're making 5 HP putting down the road or in the pits. It just dumps oil in the intake manifold and makes you knock on track due to the octane reduction. I'm telling you, SRs will be just fine running a decent sized line through a catch can and to the intake tube. Put it 60 degrees angled towards the compressor wheel - lots of suction.

[quickdiversion]

Originally Posted by PoorMans180SX

The point is not to build vacuum, as what you're stating is correct. The point is to generate flow. You can then use the intake like a venturi in a carb, and draw air through the system using the intake flow. The closer to the turbo the better essentially, as long as your catch can is able to keep the oil and vapors separated.

This is why exhaust evac works as well, no vacuum, but lots of flow. Again, as long as you can keep oil from disappearing out the exhaust.

You should always use a nozzle with a slit in it for either. Like this:



This guy has tested it. No vacuum, but less crank case pressure with his compound setup.

http://www.dsmtuners.com/forums/cust...on-system.html

That is the exact piece in my exhaust 7 inches from the outlet of my HX35

[MPIracing]

Originally Posted by jr_ss

If your dipstick is popping out, it's because you have, A. Worn out o-ring on the dip stick or B. Excessive crankcase pressure from bad rings or a failed PCV.

Got a new dipstick, motor is just rebuilt,

Guess my pcv has failed ??
Any way to test it or shall I just get a new one

[MPIracing]

Originally Posted by 5280Vertidea ET

Isn't your dipstick popat least bad sign of vacuum or pressure?

That being said, on my FWD SR20DET my dipstick kept popping because I didn't realize that my intake line was kinked.

PS I've have read this whole thing and my mind still can't really grasp most of whats going on...


EDIT: Fucking GORGEOUS engine bay!

Yeah thanks, just want it yo be stealth & work, still registered car and cops hate import here in AUS.

Same I have no idea what these guys are on about, but atleast I stopped my catch can filling up

[jamg]

so my fuel rail has no part to connect to the PVC. it's currently just left out in the open.

what do you have it connected to?

[MPIracing]

Originally Posted by jamg

so my fuel rail has no part to connect to the PVC. it's currently just left out in the open.

what do you have it connected to?

My one is in the stock port to my greddy intanke manifold

[quickdiversion]

Hopefully this diagram will help you all explain it to him. This is from the JAP version of the 180sx .pdf manual



Here is a shot of the back side, as you can tell, it is not on the fuel rail. It is behind it.



And for good measure, here is a breakdown

[Options13]

so when running that vibrant venturie does that slit in it need to be exposed? I was just going to make a plate and run the venturi thorough my o2 on my turbo elbow, but the metal is so thick that the slit in the venturie won't be revieled.. is this a big deal?

also should i run a 1 way check valve too?