Hey guy's, getting close now. After sealing and Torquing my intake manifold I realized I should of addressed the PCV (Positive Crankcase Ventilation) System first. I'm finishing up my Turbo 3800 in my Fiero. And learning as I go. So I know that I have to re-configure since the intake manifold is seeing pressure instead of vacuum, I obviously don't want to pressurize the crankcase, and don't want to just disable it and keep the Valve Cover Breather I have now. I've done my homework, and just want some reinforcement.

My Plans...

1. Being the F-Body intake I have, and others have the PCV inside I have to plug the port inside the UIM that sucks the oil vapor from under the LIM, through the PCV Valve and into the Intake charge. Best to Tap or JB.Weld/Silicone a plug in?

2. I Assume I have to plug the stock PCV Breather tube that goes to the Throttle Body, Since I already have a Breather for the Valve Cover, that will filter in clean air.

3. I'd like to drill a hole in the diamond shaped PCV Cover, and add a fitting and hose to suck out the Oil Vapor/Fumes from that point. Or should I block off that whole passage and suck the fumes from the other (Non Breather) valve cover instead?

4. I decided I want to suck out the Vapor/Fumes by using the vacuum from exhaust flow by using a "Slash Cut" Pipe with a inline check-ball. I do not want a catch-can, or to burn the fumes through the intake at all.

5. For those with Wastegates did you have the outlet go straight to atmosphere with a short "Screamer Pipe" or did you tie it into the exhaust post-turbo? (Obviously quieter but worth the extra money/fabricating?)

6. I'm thinking if the WG vented straight to atmosphere I should put the Slash Cut PCV Pipe into the normal exhaust. But If I had the WG discharge into the exhaust I should mount the Slash Cut tube into the WG outlet pipe for more Vacuum?

Thoughts?

-Obviously the Crank Case will mostly be under vacuum when boosting, but should still have no built up pressure internally from my Breather in the Valve Cover. And driving it, I will be under boost a lot. So should keep the oil clean.
-Since I'd be using the Valve Cover Breather as fresh air inlet, should I worry about it sucking in condensation?

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1987 Fiero GTX 3800 Turbo... My Build, ST3 Cam, Lowered, Wheels, and pics enjoy!https://www.fiero.nl/forum/Forum1/HTML/089483.html

You may be over engineering. A PCV valve is a one way valve and being that the car operates 99% of the time without boost, an occasional 10 or 12 second WOT run shouldn't hurt anything. With a good breather source, pressure cannot build up in the crank case.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

I used a Turbo Supra PCV valve (buy Toyota)
https://www.fiero.nl/forum/Forum2/HTML/000541.html

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Calgary time/temp

3.4L Supercharged 87 GT Click me
Super Duty 4 Indy #163 Click me

I'm thinking I should come take a look... I'm over in Novi and would like to do a swap like that someday.

quote Originally posted by Dennis LaGrua: You may be over engineering. A PCV valve is a one way valve and being that the car operates 99% of the time without boost, an occasional 10 or 12 second WOT run shouldn't hurt anything. With a good breather source, pressure cannot build up in the crank case.

I'm not worried about pressure really, like you said with the breather. However if I don't modify the stock system under boost that breather will be puffing out oil vapor, hence catch cans. But they are messy, and you have to drain em. and I'd rather not mess with them. The bigger thing is I want to suck that oil vapor, water vapor, combustion fumes out of the engine. Venting is not enough, I want that crap out an fresh air in. Makes a huge deal on keeping the insides clean, and expelling water condensation fast.

You should keep the pvc valve operational. Without it moisture will build up inside your motor rapidly. I like the exhaust scavenge idea. I've wanted to do it for a long time but the way my exhaust is it would be difficult to put it after the wideband o2. I had my wastegate vent to atmosphere for a while and I like it MUCH more recirced back into the exhaust.

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Turbo 3800 E85 F23 5spd spec5
10.91@133.1

quote Originally posted by Justinbart: You should keep the pvc valve operational. Without it moisture will build up inside your motor rapidly. I like the exhaust scavenge idea. I've wanted to do it for a long time but the way my exhaust is it would be difficult to put it after the wideband o2. I had my wastegate vent to atmosphere for a while and I like it MUCH more recirced back into the exhaust.

Exactly^^ Before your wideband? You would tie in the PCV after the turbo, before the turbo is pressure, and who wants an oily turbo... I forgot to mention I have a top mounted turbo over the transmission so I have plenty of downhill pipe to scavenge that pcv...