I'm just finishing up my turbo and I'm wondering if you need to get check valves or use the missing link if your running the vafc hack?

 

you can run up to about 10-11 psi with no check valves.but if you want more,don't buy a missing link,just buy a borg warner ec601 check valve and run a line from the black side to the throttle body and the white side to the map sensor.slide the hose back a bit on the map side and drill the smallest hole you can in the tube.this will allow you to run as much boost as you want.the reason you drill the hole is that when you are boosted,the map sensor can see atmosphric pressure.if it were closed off,it would throw a code.with the black side to the throttle body,the map sensor will never see boost,it will see 0 psi.if you drill to big of a hole,it will have a big acuum leak at idle and idle very rich.