Originally Posted by SPOHN (Post 2374879)

After discussions with Sam at GTM there is absolutely nothing wrong with putting filters on the intake side and leaving the others side completely vented to atmosphere and using no catch can at all. That's my plan. Maybe put filters on them so nothing can go in the holes.

Originally Posted by Kingbaby (Post 2374559)

Yea...I capped off the bridge on the crankcase, and the one on the driver side. Keep the one on the passenger side going to the back of the intake manifold.

thought?

EDIT:

I'm NA

Originally Posted by Sh0velMan (Post 2374722)

Air doesn't blow out of the outlet though, you have to put vacuum on it to draw it out.

That's why I said you'll run lean unless you plan on installing an electric vacuum pump to evacuate the crankcase.

I've tested this on my own car and confirmed that without vacuum on the PCV outlet, no air passes through the crankcase (other than blowby).

Originally Posted by wstar (Post 2374853)

Running breathers on the intake side as pictured is fine, IMHO. It's really not much functional difference from the stock configuration where the intake air filters play the role of that breather (and as a bonus - sometimes there is flow reversal and/or backfire through that line - at least that won't be going into your intake). But on the other side, you should hook up vacuum through a catch can. This will actively draw negative pressure on the crankcase and keep fresh air coming in through the breathers to replace it. If you were to vent the catch can to air and cap off the vacuum, the catch can won't really do anything (you might as well be venting both sides to air as above).

Originally Posted by synolimit (Post 2379909)

The yaw sensor has no bearing on drag racing correct? Must be a lateral force yes?

Originally Posted by synolimit (Post 2379845)

I've never known a race track that will allow this during tech inspection. If the motor blows oil has a direct line out of the motor and onto the track and your headers. I've only known OEM setups with a catch can not vented to atmos to be legal. If the motor goes everything's contained and will run through the motor and crop dust everyone as you blow smoke out the tail pipe. At least then the oils had a chance to burn up a little. Yes throwing a rod out the block will contain no oil but that's if it happens and un-foreseeable. Yes I also know that's not the normal flow of air when hooked up but a blown motor can change the dynamics of the flow. I personally wouldn't run anything to atmos on the track. On the street I do.




Pic?





On other cars I've let it just come out if it needed to; vented to atmos, never had issues. I do think you'd run lean though "if" it were still attached to the manifold because it'd be drawing in unmetered air.



Except the MAF sensor already accounted for the air brought in through the real air filters. That's not fine as pictured because the manifold will now bring in air into the motor from two (4 total) different locations. One metered, one not. Only way it will work is a 100% capped off system letting the pcv's just open from pressure building up behind them, or OEM with a OCC. as stated though, Its not track legal to just let crank pressure blow out to atmos. Oil on the track or headers if the motor goes = burned alive.

Originally Posted by Sh0velMan (Post 2380032)

Yes, but disconnecting or disabling the sensor will disable VDC completely, and cripple the non-LSD cars even more.

Originally Posted by Sh0velMan (Post 2380046)

I just want to say one last time that if you put breather filters on all four PCV connections, you will have no more positive crankcase ventilation.

Your crankcase will be ventilated, of course, and any pressure build up due to blow by will be relieved, but fuel and water vapor will condense inside your crankcase every time the engine cools and nothing will forcibly remove those vapors while the engine is warming up. PCV exists for reasons other than just emissions, it keeps potentially corrosive vapors from collecting inside your crankcase.

Sam is absolutely correct that it will not hurt anything short term, but think about what is going on inside there over the course of a year or more. Water and gasoline sitting on parts that were never meant to have water and gasoline sitting on them.

I just really think it's foolish to do the "elimination" when you gain absolutely nothing by doing it and cause a vulnerability in the process. Last I'll say on it, I promise.

:tup:

Originally Posted by Sh0velMan (Post 2380046)

I just want to say one last time that if you put breather filters on all four PCV connections, you will have no more positive crankcase ventilation.

Your crankcase will be ventilated, of course, and any pressure build up due to blow by will be relieved, but fuel and water vapor will condense inside your crankcase every time the engine cools and nothing will forcibly remove those vapors while the engine is warming up. PCV exists for reasons other than just emissions, it keeps potentially corrosive vapors from collecting inside your crankcase.

Sam is absolutely correct that it will not hurt anything short term, but think about what is going on inside there over the course of a year or more. Water and gasoline sitting on parts that were never meant to have water and gasoline sitting on them.

I just really think it's foolish to do the "elimination" when you gain absolutely nothing by doing it and cause a vulnerability in the process. Last I'll say on it, I promise.

:tup:

Originally Posted by Red__Zed (Post 2380572)

With FI it's probably smarter to eliminate it than to leave it. You're looking at a very different engine ecosystem with boost.

Originally Posted by Sh0velMan (Post 2380598)

Also, in case you're trying to suggest that not having a way for backpressure from blow-by to be relieved while under boost is going to cause issues... I really think that's taking it a bit too far.

It's the same conundrum you're in with a vacuum operated brake booster. Eventually you have to go back into vacuum briefly, or **** stops working. Same deal here. I'd bet you'd need to be in boost for several minutes without a single swing into vacuum for it to even become an issue.

Edit: OH lmao, and, if it got really bad, the pressure would escape the breather inlet anyway, as that isn't valved. So there you go, pressure can't really build up anyway. At least having the outlet plumbed to vacuum means you get a good purge of the crankcase every time you go into vacuum.

Originally Posted by Sh0velMan (Post 2380598)

Also, in case you're trying to suggest that not having a way for backpressure from blow-by to be relieved while under boost is going to cause issues... I really think that's taking it a bit too far.

It's the same conundrum you're in with a vacuum operated brake booster. Eventually you have to go back into vacuum briefly, or **** stops working. Same deal here. I'd bet you'd need to be in boost for several minutes without a single swing into vacuum for it to even become an issue.

Edit: OH lmao, and, if it got really bad, the pressure would escape the breather inlet anyway, as that isn't valved. So there you go, pressure can't really build up anyway. At least having the outlet plumbed to vacuum means you get a good purge of the crankcase every time you go into vacuum.

Originally Posted by synolimit (Post 2380628)

Yeah it's not an issue. My subi ran the valve covers and crank vent to a AOS that vented to atmos. No PCV and manifold blocked off where it was running. Car ran 23psi without issue. Also what I loved was the valves and crank ran into the AOS, but the bottom of the AOS Tee'd back into the crank vent line so under boost whatever came out of the valves or crank, under vacuum it would all get drained right back into the block. This is how Crawford runs their AOS too on ken blocks car. This way its 100% maintance free and during a long race you lose no oil as a OCC will fill up leaving the motor with less in it.

Originally Posted by Red__Zed (Post 2380621)

You get the same purge everytime you go into boost, as the crankcase is positive relative to atmosphere, with none of the pressure build up while under boost (which can actually be rather substantial).

I've not messed with this on a VHR, but just offering my opinion from the bit of experience I have with FI.


You can go pre-impeller and probably get something working, but that likely gets you into other issues.

Originally Posted by Red__Zed (Post 2380635)

The EJs are a completely different animal than the VQ.

Originally Posted by Sh0velMan (Post 2380636)

It's only positive relative to atmosphere if there is, in fact, substantial blow-by. This engine is not like older examples where there is a mechanism at work pressurizing the crankcase with intake manifold air so that all you need is a single vent, it requires vacuum from the manifold to draw out said air. Without that vacuum, there is no evacuation of the crankcase, as I've said over and over.

And as I addressed in my reply, any true pressure buildup would exit via the breather, so that's a non issue.

Originally Posted by synolimit (Post 2380642)

PCV and crank vents work no different though :tup:

Originally Posted by Red__Zed (Post 2380644)

If you logged pressure in a VQ crankcase over boost, I bet you'd be surprised.

Here's one for you:

Crankcase Ventilation Mod w/Pics - Page 18 - MY350Z.COM Forums

Originally Posted by Sh0velMan (Post 2380650)

Wow, 15psi got him a 1.5psi crankcase pressurization.. that's loose as hell.

Originally Posted by Red__Zed (Post 2380646)

but the system they are connected to is designed to be operated differently

Originally Posted by synolimit (Post 2380657)

Not really. Bottom end of PCV goes to crank vent, other end has a hose running to manifold. Actually they're 100% the same as with every PCV system.

Originally Posted by Red__Zed (Post 2380659)

The boost to crankcase pressure curves look vastly different between the motors.

Originally Posted by wstar (Post 2380702)

Piston rings are never a perfect seal. That's how we get blow-by in the first place. It stands to reason that with boost coming into the pistons, a whole lot more blow-by will happen.

Originally Posted by Dzel (Post 2386281)

Looking good! Did you do all the work yourself?

Sent with TapAhoe

Originally Posted by SPOHN (Post 2386285)

Sure did. I do all my own work.

Originally Posted by SPOHN (Post 2386285)

Sure did. I do all my own work.

Originally Posted by Baer383 (Post 2386309)

And I made a PBJ sandwich for lunch.;)

Originally Posted by Dzel (Post 2386341)

Lol Baer are you "that" guy that just stands ghere and watches while everyone else works?

Sent with TapAhoe

Originally Posted by Baer383 (Post 2386346)

I've been working on cars for 28yrs it's about time I can watch.:hello: