Blow Off Valve! Return (Bypass Valve?) or atmospheric?

[quadracer111]

GTR runs 2x stock BOV behind bumper on drivers side. Synapse BOV is the only BOV I could find that has no diaphram and can recirculate when using MAF. If ECU has MAP sensor, you can recirculate or dump to atmosphere. But recirculating provides the best transient response and increase in transient hp (when coming back onto throttle after gearchange), etc.

There have been a few cases of 20-24hp gains from fitting this Synapse BOV over leaking BOV (increase in hp, torque throughout powerband) and 9hp gain in transient hp on one of the cars with 20-24hp gain in hp. Can see a leaner A/F ratio on dynograph, so BOV is doing it's job by letting boost reach engine, not being recirculated by leaking BOV and making turbo work harder.

Synapse BOV on a R32GTR with single turbo at Almasi (Canada?) getting dynoed (550rwhp) -

http://www.youtube.com/watch?v=VM_og71DCyw

When driving (can hear BOV and no surge sound) -

http://www.youtube.com/watch?v=IP0IV0sZgHE

I assume port C is connected (older type Synapse BOV before revisions were done).

This is what a Synapse BOV sounds like on RB20DET without port C connected (Port C helps BOV open quicker) -

http://www.youtube.com/watch?v=H0OBVk_UTMI

Even without Port C, Synapse BOV opens.

Just wondering what this port c is? Advantages/disadvantages to having it hooked up/not hooked up?
I am getting that car in the video on the 26th and would like to know whats up? I read in the manual that if you are running more than 7psi you have to hook up port c, this car is running 13psi, help?

Thanks

[Skym]

Port C makes the BOV release the same, no matter what boost level you run.

This videoclip from Synapse shows what happens if Port C is disconnected -

http://www.youtube.com/watch?v=71L1w77xC-M

One way is welding a 1/8" NPT metal boss fitting from Autometer on steel intake piping (intake piping that's painted black) -

http://www.autometer.com/cat_accessorieslist.aspx?pid=9

Then buy the Synapse Boost Connect Kit with 1/8 NPT fittings x2, 4mm ID hose to suit port C on BOV.

Or find a aluminium version of the Autometer 1/8" NPT metal boss fitting and weld onto J pipe (intake pipe that goes over top of engine), next too BOV which makes the distance shorter that boost signal has to travel. Basically should make BOV react faster.

[quadracer111]

Alright.
I am not to sure if port c is connected on this car.
But if I want to run it VTA, can I just buy the anti stall kit and remove the recirc hoses from the end of the bov?
Thanks

[NismoS-tune]

i bought 2x HKS SSQV this winter and will be installing them in the coming weeks,
bought these to correct boost leak at higher rpm, and because the SSQV design releases pressure faster than common BOVs
they will be recirculated, for better back-on-throttle response, and fuel economy

though i still have to source the recirc fittings, since they did not come with..

You shoulda bought the newest HKS SSQV which is 1 BOV but has 2 valves and better technology then the older twin BOVs. I had a used one for sale :S

[Kras]

if you wanna sound fast vent to atmo, if you wanna go fast recirc

[frankiman]

You shoulda bought the newest HKS SSQV which is 1 BOV but has 2 valves and better technology then the older twin BOVs. I had a used one for sale :S

whuh?
the ones i have are the 3rd generation, theres no other model since

[Skym]

Quadracer, Port C (fitting on side of BOV facing firewall) isn't connected in the videoclip and photo's I've seen in build thread. But in earlier photo's in build thread it was connected to somewhere down the front of car (intercooler piping???). He had problems with BOV leaking (boost feed hose might have been too long), so that could be why he disconnected it.

If you run MAF sensor, yes you can vent to atmosphere via using antistall kit and removing recirc hose. But with MAF, recirculating the air to behind MAF, before turbo is best for response, etc. But ECU with MAP sensor is best when venting BOV to atmosphere, as it measures air at intake plenum, so can adjust to amount of air entering engine.

[quadracer111]

Ok thanks Skym.
I will probably buy the anti stall kit for shits and giggles. Im not big on performance right now (first car).
Thanks for the help.
Braden