So i recently purchased a evo 9 bov for my evo 8 off a member from here this week. Put the bov on and when it blows off it shutters. I don't know why or what this means so any help would be greatly appreciated.

 

Try turning it around, you might have it installed backwards.

 

Ok I'll have to check that out i thought they only go on one way

 

When I bought my evo 9 it made a really loud fluttering noise when trying to recirc the air, a lot like when a hose blew off the boost gauge on my old car and the air couldn't recirc, and even though the previous owner said it was fine, I wasn't convinced. I took the valve off and the piston was VERY stiff so I ordered a forge recirc valve. The piston in that was quite a lot easier and smoother to push open and since fitting that the recirc is one nice whoosh like it should be. In my experience the evo 9 bovs may not leak like the old crappy plastic ones but they're certainly not as indestructible as people seem to think. That's just my opinion

 

Ya i feel ya man i found out it was indeed installed backwards problem fixed i appreciate the advice and help.