I realize that the combination of the lines equals out to a theoretical -15 line (2x -10 = 0.614in^2) and drops the effective vacuum of the intake side on each port, but the logic at the time was more ports with some vacuum can improve vapor collection versus one port all the vacuum.

Also I ordered the Valve Cover with 2 ports without fully thinking out the plumbing situation.

 

The logic behind the tee with the 8mm check valve -

I'm thinking about removing it, I just haven't made a decision either way.


See above post, not really.

So, you're saying you didn't appreciate the aesthetic of an early twin turbo RX-7's vacuum routing?

 

Well ****, you basically just have the 8mm check valve vta over what I have now... Maybe I do have other issues.

 

I added another line from the VC to the intake and now once my car reached op temp it started idling rich and kinda rough. I didn't try to drive it as I needed to get to work and didn't want to deal with issues on the 45 minute drive. Could that be from getting too much blow by gas into the intake that didn't go through the MAF? All I changed from it running fine, albeit smoky, was adding the additional line... When I get home I plan to just VTA the new line with a 1/2 boomba check valve in case there is ever vacuum in the crankcase to see if that helps.

Tried to work out the rear pcv fitting and that thing is in there solid, I can only get the elbow to rotate in the aluminum(?) pressed in portion, but that pressed in piece isn't budging.

 

You may need to take the VC off so you pull the pcv fitting out, then use something else to tap the aluminum piece out from the back, or use a screwdriver to pry out. Just be careful to not crack the VC.


Any air in the crankcase is metered air, so running another line shouldn't effect the car, unless it putting a bunch more fuel vapor in the intake.

 

The backside is blocked by the baffling, I haven't removed that and don't plan to. I've been in a hurry every time I've gotten to work on it. My wife doesn't quite see the importance of this hobby and with a 6mo old, the little time I have to work on it is precious.

Well it was metered, but then assumed burned, correct? its mass flow going into the engine that was assumed to have gone out the exhaust. But maybe it doesn't matter since it should have low or no oxygen since it was combusted? I don't know... I agree with you and don't know what the deal is. I'll investigate more this evening. Wife and kid will be out for a few hours when I get home. Maybe I just missed plugging something back in.

 

Well, you said it got richer, which implies there is too much fuel. If you were getting addition, un-metered or un-accounted for air, it would have went lean. So, you're either pulling oil and fuel vapor from the port, or its something else.

 

For those of you running a PCV....what fitting/fittings did you use to run the PCV valve in the larger line? In particular, the threaded side (I believe 1/8 npt) if I use the STM -10 fitting and a radium catch catch with 3/8 hose, I've searched and can't seem to find a proper fitting. My brain could also be a little fried from reading this entire thread... Thanks.

 

I have a boomba check valve. Ditched the stock PCV.

 

Those look nice. I should've looked those up earlier. I believe mrfred wrote somewhere that ditching the stock PCV could cause idling issues. Do you have any issues with just the boomba valve? Right now I'm still running a stock turbo with bolt ons and a tune, with plans to upgrade soon.

 

I run the 3/8" valve, and Idle is fine right 1,000-1,200 with the GSC S2's with tweaks to the idle settings in the ROM, and I think my BISS is fairly closed to closed (maybe only 1 or 2 turns out).

 

Great. I have no idea what BISS is, but I get the gist. I'll go with the boomba to make my life easier and I plan on getting S1 or S2 cams so I'll have to tweak the idle settings anyway. Thanks again.

 

Be Idle Set Screw. Its a little screw on the throttle body that control an air bleed port. You use Evoscan to disable the IACV, play with the BISS so the motor idles a touch above your target idle. Then the IACV can usually compensate, or may need minor tweaks in the tune.

 

OEM PCV
3/16" BSPT Female x 1/8" NPT Male
1/8" NPT Female x 3/8" Barb

The BSPT female fitting alone made it expensive enough that I should have tested my luck out with the Boomba check valve.

 

Thanks for the info guys. I'm going to go with the boomba valve and see how it works out.