[milfriez]

Hey everyone,

Just installed a Stett CP along with a Synapse BOV this weekend. I looked all over the place and couldn't come to a complete decision.

I replaced the hose from the manifold to the Y and then replaced the Y and both hoses to the BOV inlets with silicone hose from Verocious Motosports. I read and looked all over the place, and it looked as if having both ports A&B connected on the synapse BOV provides the best seal (and apparently sound). But mine doesn't even make a peep unless I'm well into 4-5k RPM and then its a gentle hisssss. Not the giant chirp/WHOOOSH other people have commented on Synapse making.

Am I doing something wrong?

I should also note that im currently troubleshooting some half/engine light issues over at n54tech also. But was asking on here about Synapse since Ive seen it was a popular option in the past.

Anyone have any ideas?

btw- also running catless, stett CP, synapse BOV, BMS DCI, and JB4
2007 335xi


Thanks!

[Jeff@TopGearSolutions]

Snap a pic

[milfriez]

It's all buttoned up right now, it's hard to see. The stett CP has the Synapse sitting pretty low.

I'll see what I can get but without taking everything out again its hard to show.

Basically its
Manifold--->Single silicone hose--> Y removed from DVs ---> One hose to each side of Y ---> both inlets on the rear of the Synapse

If you look at this pic, on the rear of the Synapse are the two inlets. I Y those to a single hose going into the intake manifold.

[Jeff@TopGearSolutions]

http://www.synapseengineering.com/su...V%20manual.pdf

Check out these instructions here.

[milfriez]

Thanks for those.

I actually read those a while back, which is where I got the idea for connecting both ports. The C port they mention on there has actually been eliminated with their V2 version, so it doesn't exist any longer.

http://synapseengineering.com/suppor...-c1-pg2-p.html

The T it shows on there is almost identical to mine. Long tube from the intake manifold to the T, and only about 2 inches to port A&B on the Synapse. So according to that document, aside from the port C being gone, that is how I have mine setup.

I'm starting to think that I might have a leak elsewhere in the system. When I got WOT in 2nd or 3rd, sometimes I get a half/engine light, but it doesn't go into limp mode. When that happens, it struggles to build boost, but no codes show up in JB4 aside from possible catless detected (which is true); even with auto-clear turned off.

I am using the verocious motorsports 4mm silicone hoses for the plumbing, but all the rest of the hoses are the original ones.

[mattgu40]

I think synapse is a terribely design Bov..

first read the Troubleshooting guide on their website,

second ensure the oring placement on the flange is correct the oring goes in the Bov and not in the recess on the flange neck.

If still struggeling pop the back plate off and ensure the valve isnt stuck
there is 2 ways it can get stuck the preload spring (little one ) fails and stays stuck. you can remove without any major negative effect as they say,

then the whole Valve can stay stuck on the back cap (which happens to me all the time), where i think the design is terrible.

hope this helps

[milfriez]

Thanks for the info.

I bought the CP and BOV second hand from a member on here, so I can't comment as to the functionality of it historically.

I did happen to notice that they have a new V3 out, with some updated parts and different barb on the back. I might try and rebuild the current unit I have and see what happens.

The problem is trying to get ahold of anyone at that company. I submitted a ticket and still no one has gotten back to me yet. So it will be hard to get any info on what I need to rebuild the unit. Plus, I'm not real keen on drilling out my intake manifold for the larger 1/8NPT barb. Afraid I would destroy my manifold.