Slash cuts, whos got the info?
 

Hey guys,

There is a bit of info on googles, not much, whos done one, specifically I want to know angle, location in downpipe, and how long the metal tube needs to be so the rubber hose isnt heat affected.

Thanks,
Dann

I'm doing this right now. I got a vibrant performance slash cut with an angle cut o2 bung. I'm cutting off my secondary o2 sensor mount that is on my FM downpipe, and that's where I'm welding my new bung. It has a -10AN fitting on it cause I'm using a stainless braided line instead of a rubber hose with clamps.

actually, faefae of all people is the one person I distinctly remember running this.

and it sucks (both literally and figuratively)

And the rubber hose just 2 inches or so from the main exhaust will be fine?

Im talking about heat travelling up the metal components.

Dann

More info please.

Dann

True miata turbo style you give me almost 4000 posts to wade through.

Ill try to search from here, thankyou.

Dann

it doesn't work as well in application as it does in theory
it introduces lots of potential failure points and clutter
it makes your exhaust stink and smoke at times
you spew oil outa your exhaust pipe at times

Ive never ran one so this is all info I'm getting from the interwebz

ask Brain or soviet who have both seen fae's setup in person

Not really. OPen thread, go to tools, search within thread, profit

lol, sorry but I don't want to wade through them any more than you do. IIRC he put it in around the time that he switched to the S366 setup, so that should narrow it down a bit (not really).

:dealwithit:


Wow, I've never used that because I assumed it was rubish like the other search tools on the site. That's useful, because Google indexes the threads @10/page and I view at 60/page, so it's useless for finding things within threads.

Nah, he had it way before then, even with his begi 30r setup.

I think he revised it with check valves or something, but in typical fael fashion just made it worse LOL

I intend to run a big catch can with it and stock pcv valve as check valve.

I can make the can myself so I can do whatever I want in terms of design, hence trying to narrow it down a bit.

1/2 inch hose, big baffled catch can, both sides of cover vented to catch can... win?

Dann

To make it not smoke you need good baffling in the head, and you need to not pull from the intake manifold side. You dont want a catch can on it because that will reduce the effective vacuum. My ultimate crankcase vent system goes a little like this.

-12 port on the rear intake side of the block where Bundy has one, this is the block not the head.
-10 port on the head where the exhaust side port is
-10 port on the rear exhaust side of the head, add a baffle in the head here

Run the -12 port to a slashcut with a check valve in the downpipe, no catch can.
Run the front exhaust side port to a good baffled catch can and then to a slash cut in the turbo inlet.
Run the rear exhaust side port to a pcv valve to a different baffled catch can to the intake manifold (can be substituted with a vacuum pump if you really want to ball hard, but you ditch the pcv and put a vac regulator on the turbo inlet slashcut line).

Hopefully over the winter I'll switch to this setup, I need to pull the engine and the oil pan anyways to fix the multitude of leaks so I might as well drill a massive hole in the block.

Interesting, Prepared specifically disallows this, but not SP or SM.

https://www.miataturbo.net/attachmen...ine=1376490787

Subscribed.

I take it a vacuum pump is not an option?

LOL I wasn't gonna ask, but now I gotta: are you seriously measuring a ton of pressure in the crakcase?

I mean if we're gonna go as far as suggesting vacuum pumps, this better be some 800hp monster that creates massive crankcase pressures

From what I've seen in my limited research only the mechanical vac pumps flow enough air, but at that point you might as well spend a little more dough and go with the complete drysump system. The electric one of choice (oem corvette?) cant seem to pull enough vac on its own, which is why I suggested only using it to supplement the other two sources.

You dont need a 800hp monster to benefit from always having the crank case under vacuum. Even a normal car should be able to gain a noticeable amount of power due to better ring seal.

When this was first brought up a year or two ago the info showed that it wasnt about crankcase pressure, it was that vacuum helped the rings seal better.

wat?

I don't think I'll have The opportunity (read budget) to do an awesome setup, because its not on my car and Ill be getting paid a finite (read tiny) amount to do it, basically because I volunteered myself to build a catch can.

I have alloy on hand, and the correct drill and tap to use cheap brass push fittings, so I can build the catch can however I want with all the ins and out i want, and I can drill and tap the cam cover all I want but I have to keep fancy fittings to a minimum.

I was thinking 3/8NPT x2 out of the exhaust side of the cam cover, with 3/8NPT x1 outlet from the top of the can to a slash cut, with a single 3/8NPT at the bottom to either go directly back to the sump like an MSM or to a tap.
I can baffle the can however I want.

Make suggestion I'll build it.

Dann