Ok This is odd. I installed my Synapse BOV and its hooked up to Recirc. It holds boost under WOT at 25psi just fine. While regular driving it will flutter around 12psi and on the highway its awful. I took a video and have it hooked up both ports going to the Y and into the Intake Mani. Stock routing from the stock BOV..

I have an EVO IX MR with Stock Turbo HKS Intake, Muse UICP, ETS IC, ETS LICP. 269 cams. Works DP and exhaust. Just to give u the quick and dirty mod list.

I have adjusted the middle screw on the BOV all the way down and all the way up. Not much of a change at all. Hopefully the video will show it better. Let me know your thoughts on how to fix this. Thanks.

http://youtu.be/01SJjnhXeSE
http://youtu.be/aSKxsIcs7OA

 

i dont see a video or a link. is it an older larger bov or the newer smaller unit.

 

Sorry was having some embeding issues. Its the Older big version. Posting pics of the install as well.

 

Bunp any thoughts

 

Bump

 

what turbo you running?

 

Stock IX turbo

 

Have you tried just the A port or just the B port?

 

edit

 

By new do you mean without the C port? That's the same one I have, unless there's a third, newer one. At first I only had the A port connected and it behaved similarly to how yours is now. I tried just the B port and it was the same. When I connected both A and B with a Y, it was perfect.

Are you sure that disconnecting just one of the 2 ports causes the car to stall? (You have to take out the Y as well)

 

Sorry no sleep. Took off the Y on port A right now. Flutter is worse. Will try B. with both connected its awful

 

With just port A it flutters during every shift. I have the pre load spring all the way down. Tryin port B now.

 

Ok just with B worst yet.

 

Ok stupid question. Took the BOV off and noticed the hose from the head that goes into the intake was off the intake. Isn't that just the pcv valve hose. Would that cause the BOv to flutter like that? I know a stretch. Didn't have time to bolt it back up yet.

 

I do have a Synchronic BOV that is the original version (coke can size) like yours. They both function very similarily from what I have seen just size redesign is evident in the latest compact model. Also what was know as port "C" has been deleted in the newer version.
This port "C" deletion was supposed to address some of the part throttle issues associated with this BOV although I have still heard some users are saying it is still evident.

I just want to throw out what has had the biggest influence in dealing with part throttle issues in my dealings with this BOV.

* I removed completely the preload spring inside the valve through disassembly. (This was also recommended by Synchronic) This takes preload adjustment out of the picture altogether. verify that all fittings and fasteners are tight!

* Removed small factory vacuum hard line from Evo intake to BOV and replaced with larger diameter vacuum line. I use nylon which is rigid and will not colapse or expand under boost.

* I used port "B" to control the valve and leave port "A" open VTA. Try just "A" or just "B"
or both to see what works best for your case.

* I noticed valve responded better when placed in a position level to the ground...in otherwords not mounted in upright position. Mine lays parallel with my UICP.

I still do have some part throttle flutter at times and I personally do not think it can be 100% resolved when using a smaller stock frame style turbo. (i.e. FP green, BBK full) FP reds and BBK-B's and larger seem to notice far less flutter if any.

Hope this helps