im planning on making up a new intake pipe for my car. i was just wondering which lines must stay connected to the intake pipe. theres the big hose that connects to the SMIC as well as the smaller line on the opposite side, do i need either of them?
I want to say no to both. The larger hole is for recirculation bypass valve, and a I think 1/4 inch small line is for venting the carbon canister. I believe there is a third line that is for the crank case ventillation. I would keep that line intact, but you can put an air breather on the hose insetead.
Darek
If this is for an sr, the only line you need are vaccuum for the fpr, the wastegate actuator and a bov if you are running one. I like to keep things stock, since they are usually there for a reason and probably won’t terribly hurt performance or emissions, so I’d just incorporate them into the new intake.
I’d keep the crankcase ventalation hooked up, also if you do the charge piping you’ll need to do the idle control line aswell.
is your car all apart now??? Sound like your going mad with your welder 
haha ya its somewhat apart. i still cant decide if i should make a few braces inside the car or do a 4 point cage or something… seems like my best bet is to leave all my lines on my intake. i was told you dont need the recirculation bypass valve. might just plug that off.
ya plug it off and same with the vaccume line going to it.
Weld said intake up to the intake turbo extension. That has all the crankcase ventilation lines you need.