okay im using the easy route for right now..i have a LS im trying to boost. I went to the pet store and bought the check valves. on one end it says "air in" and the other side says "air out" I know this maybe a dumb question but I gotta know which way they are suppose to go...i already did the t fitting and everything just wanna know if im suppose to have the "air out" position facing the outside and the "air in" connected to silicone hose. thanks for any help

 

"air out" goes towards the intake manifold or any source the vacuum is coming from. those check valves dont work very well if your using them for the map sensor on obd1. If yours is on the throttle body you should have a missing link. Just a little advice.

 

i thought the air in should be connected to the vacuum source, oh well. ditch your check valves and fmu setup. uberdata

 

thanks guys its a obd2 no wonder it wouldn't boost i had it the other way around...

 

I second the air in part. You will have to run about 4-5 check valves to be able to run 8-9 lb's of boost. Your best bet it to get a missing link.