problem solved

 

The 9 valve makes part-throttle / on-off transition a little funky.

Your BOV will still release a little pressure when you abruptly lift, however it will not hold pressure that well either when "in boost". When "in boost", the pressure on the back side of the diaphragm helps the valve stay closed as well as aid in opening when in vacuum.

 

It's a combination of both, pressure on the valve face and vacuum from that line that opens the valve.

 

My plastic 8 bov broke when the guy in the auto parts store said "can i see it to compare it to the vacuum hose bins in the back?"....1 minute later "I...umm, it slipped out of my hand when I opened the door"

Love the evo 9 valve though, not too incredibly noisy though.

 

I have my stock 8 valve you can have ... just pay shipping.

 

Good to know there's still good people out there! I just purchased a 9 valve though, I appreciate it very much tho sir