Right, which is why I think OP can easily just stick w/ stock

Stock setup with a catch can to avoid blowby being picked up, it'll catch what little you'll have move and not screw up normal operations.

Here is the current deal. I was an idiot and wasn't thinking with what I did before. Vent filter on exhaust and intake side goes to catchcan and catchcan goes to intake. Maybe not perfect, but it should suck the poison out now.


https://www.miataturbo.net/attachmen...ine=1444961254


Yes i need to loom the harnes and etc. Still a work in progess.

No, before you had it right. Now it's wrong.

EDIT: misread his post

I don't know, sounds like he had it right all along. Vent filter on exhaust, can between intake and pcv. There's only two lines on the catch can, so the exhaust side can't be hooked up there too.

It's pretty perfect for a street car!

Before both valve cover hose did a YY, connected together, and then to the catch can and then to intake. No flow only vacuum. Now air can flow through and go in pre throttle. I after the throttle would piss with idle as it would be a massive vac leak. Both in a Y under vac only idled OK ish.

It's not a massive vac leak though, it's a steady controlled crank cleansing stream that can be compensated for. The stock PCV valve is designed and sized accordingly, and it works stock.

At least that's how it should be, the catch can hooked up post-TB to the stock PCV hose port on the intake manifold.

What you've got now sees no vacuum most times. That would be a much better location for the exhaust side vent, if you didn't want a breather filter.

I have a slash-cut. Works well. Order of operations is :

Fresh Air > Moroso filtered VTA catch can (intake) > AN10 to Valve cover > ENGINE > AN10 to sealed Mishimoto Baffled Can > Vibrant Check Valve > Vibrant Slash Cut.

Sooooo Slash cut pulls vacuum, Fresh air comes in from Filtered VTA can, no nonsense in my intake manifold.

Car is NA right now, but will be turbo soon. The way I figured it is that as volume of exhaust gas increases, so will vacuum being pulled. Should work well when needed in boost/full throttle.

Do you have data on how much vacuum it pulls?

Nope. Not yet at least. Would like to get some data from it, but priority has been getting trubo going. :likecat:

Now it won't idle below 1200rpm. Even with the idle valve closed. I think it is the stock style route with out a pcv valve. Just don't have one here is all. Vent filter on the exhaust side. Starting to think a VTA would just be easier. I just wanted to suck the nasty out of the crank case. Most things I've read say vacuum on the crank case is good.



https://cimg8.ibsrv.net/gimg/www.mia...29288b6f79.jpg


This has no real vacuum under low load and idle.




https://www.miataturbo.net/attachmen...ine=1445203104


This I think is basically how the factory route is. EXH side goes pre throttle/post filter, intake valve cover port to catch now to intake mani. Won't idle even with valve closed and spaz idle. I imagine the stock PCV introduces enough restriction maybe to idle or I'm all screwed up.

Vibrant slash cut? I'm going to buy one and put a map sensor on it.

If vacuum is the important bit hen why not run both valve cover vents to the catchcan and then to the intake mani? No pre throttle post filter? Been reading through threads and so many pissing matches. I seems getting rid of the blow by crap is the the big issue. I'd think some air flow would be required for that, but I'm guessing the "flow" is from the continual addition of blow by gasses. Not from an outside source like a VTA filter. Stock both sides are on vac of one sort or another.


https://cimg2.ibsrv.net/gimg/www.mia...e09597878e.jpg


Always vac.

Pulling vaccum is cleaning out the crank case and pulling in cleab air. This won't work when under boost.

Just bought a slash cut to try out and see if it actually pulls vacuum.

They work at high load VERY well. Very common on circle track cars I watched when I was younger, everybody ran them to pull a vacuum on the crankcase for extra power. Those usually had them right at the collector of the headers with a 5/8" or so hose hooked to it.

Do these pull significant enough vacuum? Seems like this would be a really nice solution. Just run the passenger side valve cover hose to a can, and the other end to the pump. Keep your intake nice and clean.

Because there is no flow.

I don't know what's wrong with your car, but if it won't idle with a stock PCV setup with extra catch can something is terribly wrong.

Anything other than stock with a catch can is a waste of time. Normally one side is on the intake at vac, and the other is at ambient pressure to introduce flow, it can be vented to the atmosphere if no MAF. I am not saying this again.

I don't know, but it's not a PCV pump but a brake booster pump. I imagine it puts out a massive amount of vac at a really short duty cycle.

I agree that it needs vacuum, deezums. For anyone else disagreeing, do you have any long term results to show for anything else that doesn't use a vac source (at least for a street car)?

I posted my HF/PrimeFit can in another PCV catch can thread but I can't find it now. I recently took a look of the inside of the IM (on my other car) that has had a Husky can between PCV and IM since 2007, about 50k miles later, it is not that much dirtier (wish I started with a brand new IM). I can post a pic before/after but it is not a Miata manifold.