Wastegate opening before BOV issue - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

TriniTT · 11-16-2009, 09:09 PM

Hey all, I have an s13 redtop in my 96 s14. I've had this motor in an s13 before as well, and originally it had a VG30DETT recirc valve as my bov. Well, over time I have read posts about the sound it makes when it releases air, and I began to get curious. I decided to install a Blitz DD bov to satisfy my curiosity. Suffice it to say, I'm even more curious now.

Basically, when the boost is let loose, it makes a fluttering sound (which I've come to learn is a form of compressor surge). I tuned the Blitz bov to open at a very light pressure.

Here is when my issue comes into light: the first thing to happen is the wastegate opens. I know it's the wastegate, because under heavy WOT, the bov will open and it's quite loud. However, under normal, average driving, the wastegate pops open and makes a loud fluttering sound, but the bov doesn't do anything.

I'm running stock boost, stock t25, stock wastegate and actuator, stock everything. I have no exhaust leaks anywhere, my gaskets are all good, esp. around the turbo. My wastegate vacuum line is coming from the lower left nipple on the intake manifold, and the bov is coming from the top right nipple. I even adjusted the wastegate actuator by turning the arm inward more, so I had to pull the actuator arm out hard to get it to reach to the wastegate arm.

Any help and input would be greatly appreciated. Also, I know a recirc is preferred, and once I figure this out I'll recirc this valve again; but for now, I need the noise to be loud so I can diagnose the problem best. Thanks!

11-16-2009, 09:09 PM	#1
TriniTT Zilvia Junkie Join Date: Jan 2009 Location: Birmingham, AL Age: 40 Posts: 444 Trader Rating: (6) Feedback Score: 6 reviews	Wastegate opening before BOV issue Hey all, I have an s13 redtop in my 96 s14. I've had this motor in an s13 before as well, and originally it had a VG30DETT recirc valve as my bov. Well, over time I have read posts about the sound it makes when it releases air, and I began to get curious. I decided to install a Blitz DD bov to satisfy my curiosity. Suffice it to say, I'm even more curious now. Basically, when the boost is let loose, it makes a fluttering sound (which I've come to learn is a form of compressor surge). I tuned the Blitz bov to open at a very light pressure. Here is when my issue comes into light: the first thing to happen is the wastegate opens. I know it's the wastegate, because under heavy WOT, the bov will open and it's quite loud. However, under normal, average driving, the wastegate pops open and makes a loud fluttering sound, but the bov doesn't do anything. I'm running stock boost, stock t25, stock wastegate and actuator, stock everything. I have no exhaust leaks anywhere, my gaskets are all good, esp. around the turbo. My wastegate vacuum line is coming from the lower left nipple on the intake manifold, and the bov is coming from the top right nipple. I even adjusted the wastegate actuator by turning the arm inward more, so I had to pull the actuator arm out hard to get it to reach to the wastegate arm. Any help and input would be greatly appreciated. Also, I know a recirc is preferred, and once I figure this out I'll recirc this valve again; but for now, I need the noise to be loud so I can diagnose the problem best. Thanks!