I just installed a Blitz SS BOV on my S13.
I have a few questions regarding the tuning.
I rev the car just standing under the hood and looking down into the BOV.
Loose setting:
Mild revving, the is a deep rattlesnake-like whoosing in the pipe. The blow off valve piston is not moving at all.
Medium revving results in some more whooshing (surge I believe) and the BOV is still not not moving.
Some harder revving releases the blow off valve but only a little bit.
Medium setting:
Mild reving - the whooshing in the pipe is more of a continuous sound, the BOV piston isn’t moving here.
Medium revving results in a louder whooshing sound with a bit of resonance inside. BOV piston isn’t moving.
Hard revving opens up the valve. Loud.
I’ve adjusted the screw from very long (loose) to very short (tight) and I have no idea what the correct setting is.
Shouldn’t be BOV piston open up a little bit even if it’s making like 2-3psi boost at the time?
Could there not be enough vacuum? On this particular vac line I have the fuel pressure regulator and the BOV. On the SR20DET how many vacuum lines do I have and which ones can I use?
When driving (under load):
When I rev the car up hard under load in 1st gear up to 6000RPM+ the BOV opens up and is loud.
Continuing onwards, there is about 1s lag (foot to the floor) and in 2nd gear. At 6000RPM+ the BOV is barely releasing any air. I am running full boost (7psi) because I am WOT and I can definately hear it spooled.
From third gear, WOT and letting off there is no BOV sound. I just hear a deep whoosh. Any ideas?
My ARC Super BOV also behaved in the same way so I think it may be a weak vacuum.
I am going to get the recirculation kit as soon as I can find one for this BOV but for now I want to know why it isn’t opening at very small psi? Maybe if anybody has any vacuum hoses kicking around I might pick those up to replace a few of my lines.