Girly Catch Can Mounted - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


DIY Turbo Discussion greddy on a 1.8? homebrew kit?

Reply
 
 
 
LinkBack Thread Tools
Old 05-28-2008, 11:44 AM   #21
Elite Member
Thread Starter
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,244
Total Cats: 291
Default

show me- I was using what I thought was a first gen supra turbo pcv valve (non OE). Had a metal valve core, but after 1k miles was already leaking.
m2cupcar is offline   Reply With Quote
Old 05-28-2008, 12:54 PM   #22
Junior Member
iTrader: (1)
 
Join Date: Sep 2006
Posts: 464
Total Cats: 0
Default

I'm refering to a turbo bypass valve. We make a replacement, the OEM piece should look like this but in plastic:
http://www.forgemotorsport.com/conte...duct=FMDVMSP02

Manifold pressure will open or close the valve when its needed. Under boost it will be shut, open under vacuum. You can get them online or at junkyards for a song. That and a few reducers should do the trick...

I plan on trying one of our fancy alloy jobbers once I get the turbo in my car...
PAT! is offline   Reply With Quote
Old 05-28-2008, 01:11 PM   #23
Junior Member
 
Join Date: Feb 2007
Location: 11368 miles from where i would like to be
Posts: 269
Total Cats: 92
Default

Quote:
Originally Posted by m2cupcar View Post
no, the problem was there were rockers in an mx6
LOL

Quote:
I think the real problem was that the vent hole is about 1/8" - hard to blow through, so I'm sure it's equally difficult to vent blow-by thru
Agreed, for extreme use (of whichever type) it is far too small in there. Hence open it out, add another on the other bank, and do what you wish with them, BUT, leave the pcv system in place and in good condition.

Fred.
rb26dett is offline   Reply With Quote
Old 05-28-2008, 01:51 PM   #24
Junior Member
 
Join Date: Feb 2007
Location: 11368 miles from where i would like to be
Posts: 269
Total Cats: 92
Default

Quote:
Originally Posted by PAT! View Post
I'm refering to a turbo bypass valve.
You don't think the idle might be a wee bit high with a 19mm hole to breath through and bypass the throttle do you? How else would you use it?
rb26dett is offline   Reply With Quote
Old 05-28-2008, 02:01 PM   #25
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,900
Total Cats: 1,792
Default

wouldn't the simplest solution be a one way check valve inline with the pcv. that way the pcv can still work as intended, and the check valve would be extra insurance that the crankcase will never get boost.
Braineack is offline   Reply With Quote
Old 05-28-2008, 02:10 PM   #26
Junior Member
 
Join Date: Feb 2007
Location: 11368 miles from where i would like to be
Posts: 269
Total Cats: 92
Default

Quote:
Originally Posted by Braineack View Post
wouldn't the simplest solution be a one way check valve inline with the pcv. that way the pcv can still work as intended, and the check valve would be extra insurance that the crankcase will never get boost.
But but but, that's exactly what a pcv IS :-) I good nice softly sprung good sealing check valve would be excellent, you could always bring the flow down if you wanted to by using some sort of restrictor inline with it.
rb26dett is offline   Reply With Quote
Old 05-28-2008, 02:41 PM   #27
Elite Member
iTrader: (3)
 
AbeFM's Avatar
 
Join Date: Aug 2006
Location: San Diego, CA
Posts: 3,048
Total Cats: 8
Default

I couldn't find a good check valve, but I did put two in there, hoping the pressure drop across the first would be enough to leave one left. Probably crap, but it's what I did.

Quote:
Originally Posted by m2cupcar View Post
I've yet to see it, but word is under very harsh conditions (track events) the captured oil gets heavily contaminated with water, creating an oily froth. So that might be a reason not to dump it back in.
That makes total sense. People who take short trips like me get water in their oil, when you drive for a long time, the water should boil out. Ok, it would be awesome to seperate it, but you can probably change your oil less often if you don't dump it back in.

I think you can dump it back in by hand if it's clean. After the water comes out.


Quote:
Originally Posted by rb26dett View Post
Dip stick was 4 inches too high after a lap. The hose from the end of rocker went straight down and out the bottom with no bottle/restriction at all. NO turbo. ie its marginal in stock form when thrashed hard. Of course that must have been caused by magic boost dust leaking past the pcv valve right...
Isn't boost-dust something you can pour in the tank? I'm kinda wondering about the lack of suction....

Quote:
Originally Posted by PAT! View Post
I'm refering to a turbo bypass valve. We make a replacement, the OEM piece should look like this but in plastic:
http://www.forgemotorsport.com/conte...duct=FMDVMSP02

Manifold pressure will open or close the valve when its needed. Under boost it will be shut, open under vacuum. You can get them online or at junkyards for a song. That and a few reducers should do the trick...

I plan on trying one of our fancy alloy jobbers once I get the turbo in my car...
What does something like that cost? If the megasquirt had more channels, you could make it electronic. :-)

Anyway, having a suction would help - with a decent catch can, you could plumb it back into the intake, ahead of the turbo, and that can't hurt. But perhaps a bigger bung would help.

There's not as much use to sucking off when not on boost..... And on boost, all these check-valves are closed. If it switched to atmospheric would work....
AbeFM is offline   Reply With Quote
Old 05-28-2008, 02:55 PM   #28
Junior Member
 
Join Date: Feb 2007
Location: 11368 miles from where i would like to be
Posts: 269
Total Cats: 92
Default

Quote:
Originally Posted by AbeFM View Post
I couldn't find a good check valve, but I did put two in there, hoping the pressure drop across the first would be enough to leave one left. Probably crap, but it's what I did.
Probably not a bad idea at all!

Quote:
Isn't boost-dust something you can pour in the tank? I'm kinda wondering about the lack of suction....
You have to lift to get suction :-) nurburgring = extended periods at WOT and 120+ mph

Quote:
There's not as much use to sucking off when not on boost...
Not true :-p (least, that's not what that red head of yours told me the other night ;-) )

Fred.
rb26dett is offline   Reply With Quote
Old 05-28-2008, 03:36 PM   #29
Junior Member
iTrader: (1)
 
Join Date: Sep 2006
Posts: 464
Total Cats: 0
Default

I used to get them free from Supra owners after they installed an upgraded valve. Maybe 5-10 from a junkyard.

The valve should pretty much exactly mimic the operation of a check-valve but without the leaking and blowing open.

I'm proposing installing it off of the valve cover, flow should be restricted by the size of that orifice.

Sorry I didn't quote, I'm feeling lazy...
PAT! is offline   Reply With Quote
Old 05-28-2008, 03:45 PM   #30
Junior Member
 
Join Date: Feb 2007
Location: 11368 miles from where i would like to be
Posts: 269
Total Cats: 92
Default

If it were a steady state flow it would mimic it exactly, but being a pulsed flow it will not. It will puff out and then back in again. With the check valve it works like a small pump removing gas with each pulse.

Think about a piece of elastic with a ratchet on it.
rb26dett is offline   Reply With Quote
Old 05-28-2008, 03:54 PM   #31
Elite Member
iTrader: (3)
 
AbeFM's Avatar
 
Join Date: Aug 2006
Location: San Diego, CA
Posts: 3,048
Total Cats: 8
Default

So... Why not hook it in backwards.

You have a check valve to the intake manifold, so when in vacuum, you get suction into the motor. When on boost, there's no flow (unless your crankcase pressure is higher than boost pressure). No catch can here

Also, have a boost actuated valve, when the engine boosts, it would open, the rest of the time it's closed. This would have a catch can, and vent to atmosphere (or maybe between air filter and turbo). The giant opening wouldn't matter since it would only be open on boost, and doesn't go to the manifold so it won't effect idle.

So there's no vacuum leak to worry about, you're covered under boost and vacuum, you're not leaking all over the place, and your crankcase is well vented.
AbeFM is offline   Reply With Quote
Old 05-28-2008, 04:26 PM   #32
Junior Member
 
Join Date: Feb 2007
Location: 11368 miles from where i would like to be
Posts: 269
Total Cats: 92
Default

The big thing with the FE3 at least is just totally insufficient area to exit when the pcv is shut at WOT or on boost. The hole is just too small. Enlarging it and adding a second is a good way to go IMO.
rb26dett is offline   Reply With Quote
Old 06-11-2008, 06:41 PM   #33
Junior Member
 
Join Date: Sep 2007
Location: Brisbane, Australia
Posts: 58
Total Cats: 0
Default

I have a similar setup, but I used an electronics jiffy box w/rubber seal, stuffed it full of stainless steel wool, and put a screen in so no strands would get sucked into the motor. It seems to be trapping a very small amount of oil post PCV...
Fra66L is offline   Reply With Quote
Old 06-11-2008, 07:16 PM   #34
Elite Member
iTrader: (3)
 
AbeFM's Avatar
 
Join Date: Aug 2006
Location: San Diego, CA
Posts: 3,048
Total Cats: 8
Default

I just got a box, a nice one, and I'm stoked!

I want to get a much bigger outlet. Then I guess I'll go from that, to the can, to a T which goes to a vent or the intake manifold, with appropriate check valves.

And I should stuff the box with steel wool and screens.
AbeFM is offline   Reply With Quote
Old 06-11-2008, 11:26 PM   #35
Newb
 
Join Date: Apr 2008
Posts: 34
Total Cats: 0
Default

m2cupcar, where abouts GA are you?
^tyrant^ is offline   Reply With Quote
Old 06-12-2008, 12:23 AM   #36
Cpt. Slow
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,110
Total Cats: 518
Default

alright, so I have the stock pcv valve in, and a little filter on the driver side of the valve cover. am I using barrowed time with this setup, much like my 6" diff? I know the filter is supposed to give a sketchy idle once in a while, but I only idle when there's a spec miata infront of me on the track

mostly I road race my car, although it still sees a couple thousand (2 or 3k) street miles a year. whats the best option for this pcv issue? 323 valve? catch can? from how much everyone seems to know about the situation, I think I missed a previous thread...
curly is offline   Reply With Quote
Old 06-12-2008, 10:57 AM   #37
Elite Member
Thread Starter
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,244
Total Cats: 291
Default more testing

Near Emory U.
Went out and made a couple of ~15psi runs (sans pcv valve) from low rpm to rev limit using the OE vent and the pcv vent to the catch can. Still got oil seepage from the cam cover gasket. The passage at both ports in the Mazda cam cover is not quite 3/16" (~9mm). So I swapped in my modded Kia valve cover (post documenting cam cover mods here - and here - original thread).

Went back out and made the same runs and had zero visible oil seepage and there was no noticeable increase in the can oil level. Yes, the cam cover gaskets weren't the same- but the Kia gasket is about 3 years old and the other a year. Both feel similar. At ~9psi (waste gate actuator base) there's no problems - but the higher boost changes all that.
m2cupcar is offline   Reply With Quote
Old 06-12-2008, 11:23 AM   #38
Junior Member
 
Join Date: Feb 2007
Location: 11368 miles from where i would like to be
Posts: 269
Total Cats: 92
Default

Great test rob, and exactly as I thought it would be. Now, leave the kia top on, put the ordinary pcv back in and call it a day :-p

Fred.
rb26dett is offline   Reply With Quote
Old 06-12-2008, 11:27 AM   #39
Elite Member
Thread Starter
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,244
Total Cats: 291
Default

I need to buy a proper mazda turbo pcv. I had a third party supra unit on and it couldn't take over the base WG boost. Same with all the other OE units I have laying around... Though I haven't tried them with the new cam cover... maybe that was your point.
m2cupcar is offline   Reply With Quote
Old 06-12-2008, 11:31 AM   #40
Junior Member
 
Join Date: Feb 2007
Location: 11368 miles from where i would like to be
Posts: 269
Total Cats: 92
Default

No, I was just giving you **** :-)

Fresh OEM FTW :-)

I look forward to you having it all working properly.

HMMMMMMMMMMMM, I wonder if my leaking rear main seal is because of this?? Perhaps I didn't stuff up the install, perhaps my 17psi pushed it out!??

Fred.
rb26dett is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 59 12-15-2017 09:00 PM
Back to Stock Part Out!! Turbo Parts, MS2 Enhanced 01-05, Suspension, and MOAR! StratoBlue1109 Miata parts for sale/trade 16 10-02-2015 10:39 AM
Moroso Air Oil Separator Catch Can Aroundcorner Miata parts for sale/trade 2 10-01-2015 04:20 PM
01-05 Fab9 PNP COPs (used) FrankB Miata parts for sale/trade 6 09-30-2015 12:48 PM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 11:34 PM.