Turbo Vacuum lines and what can be plugged guide

[Mastrcruse]

Is there a turbo guide that would give me guidance on what lines need to keep vacuum and what can be plugged? I ask, and maybe my question isn’t specific enough, because I was told yesterday that the valve cover vacuum that goes to the bottom of the throttle body is supposed to be vented and the TB plugged. I was told if this was kept as a vacuum it would blow all my gaskets. I obviously want to avoid this but there are so many connections, instead of asking one by one, was wondering if there was a guide.

Thanks!

[Mastrcruse]

Maybe a different way to ask - which OEM connections (like the valve cover one) if not done correctly is gonna blow my sh** up or melt my sh** down?

[hhspunter]

You'll want to follow that advice about the valve cover. If you want to keep your brake booster functional, leave that one as is (I'm not 100% sure you can leave it totally untouched, but I had no issues with that strategy). The rest of your setup (i.e. engine management) will determine the rest of the lines. There aren't too many on the e30 so that should mostly cover it. I know I plugged at least one port on the throttle body, and tee'd off the vacuum port on the exhaust side of the intake manifold for my Megasquirt, fuel pressure regulator, BOV, and the boost control solenoid.

[citizen_insane]

For some reason my first post got marked as spam, hopefully this doesn't end up double posted:

Here's everything I can think of regarding the TB connections on my car:

• PCV line (from valve cover to TB)
  • Best thing to do is send to a catch can and pull vacuum on the can from before the turbo comp inlet. This means any oil vapor that doesn't condense into liquid in the canister will be burned by the engine.
  • Alternatively you can vent to atmosphere (with a filter on the end of the hose from the valve cover), but it's not ideal from an environmental or engine bay cleanliness standpoint.
  • You will need to plug the TB (obviously), so you can either pull out the pressed in tube and then use a cover plate, or just use a length of plugged hose.
• Evap Line (gas tank to TB)
  • Need to add a one way check valve to prevent boosting your gas tank! The one I used is here: https://www.usplastic.com/catalog/item.aspx?sku=64174
  • Make sure there are clamps on this setup, it likes to blow off if you don't.
• IAC
  • Leave it alone. I'm using mine to control idle, seems to work fine (Megasquirt MS3X)
• Brake booster line
  • I eliminated the venturi pump line that bypasses the throttle plate and just connected the brake booster one way valve to behind the throttle plate. Here's a picture of what I mean: https://imgur.com/bWRPe9F
    • The line w/ the bolt plugging it used to go to the intake piping (now charge pipe), but this would have caused boost to bypass the throttle plate. I believe it's only there to allow boosted brakes in case the throttle plate is stuck open, so just be aware you're deleting a safety feature (even if it's not super important).

I'd make sure and double check that the metal elbows (for the IAC and the brake booster) are not loose, they are a common place to get boost leaks. If they are loose, pull them out, clean them thoroughly and use JB weld to glue them back in and seal them.

[zwill23]

For some reason my first post got marked as spam, hopefully this doesn't end up double posted:

Here's everything I can think of regarding the TB connections on my car:

• PCV line (from valve cover to TB)
  • Best thing to do is send to a catch can and pull vacuum on the can from before the turbo comp inlet. This means any oil vapor that doesn't condense into liquid in the canister will be burned by the engine.
  • Alternatively you can vent to atmosphere (with a filter on the end of the hose from the valve cover), but it's not ideal from an environmental or engine bay cleanliness standpoint.
  • You will need to plug the TB (obviously), so you can either pull out the pressed in tube and then use a cover plate, or just use a length of plugged hose.
• Evap Line (gas tank to TB)
  • Need to add a one way check valve to prevent boosting your gas tank! The one I used is here: https://www.usplastic.com/catalog/item.aspx?sku=64174
  • Make sure there are clamps on this setup, it likes to blow off if you don't.
• IAC
  • Leave it alone. I'm using mine to control idle, seems to work fine (Megasquirt MS3X)
• Brake booster line
  • I eliminated the venturi pump line that bypasses the throttle plate and just connected the brake booster one way valve to behind the throttle plate. Here's a picture of what I mean: https://imgur.com/bWRPe9F
    • The line w/ the bolt plugging it used to go to the intake piping (now charge pipe), but this would have caused boost to bypass the throttle plate. I believe it's only there to allow boosted brakes in case the throttle plate is stuck open, so just be aware you're deleting a safety feature (even if it's not super important).

I'd make sure and double check that the metal elbows (for the IAC and the brake booster) are not loose, they are a common place to get boost leaks. If they are loose, pull them out, clean them thoroughly and use JB weld to glue them back in and seal them.

I hadn't considered the evap line! I was just about to bolt my throttle body and everything back up as is. Thanks for the tip!