stock blowoff valve leaks? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

sevenstar · 10-21-2009, 11:38 AM

I am wondering if the stock blowoff valve is prone to leak at 12psi? has anyone noticed their car hissing under boost over stock psi? i have not pressure tested the stock bov yet, but after reading your responses might have to

g6civcx · 10-21-2009, 12:03 PM

For a 10-15 year old engine, I wouldn't pull it pass the stock piping to have a leak somewhere.

dongoesby · 10-21-2009, 09:05 PM

i just got my swap done with stock piping and stock recirculating valve. And it does not make any sound (pssh) under boost. I'm not sure if it suppose to make a sound when you let go of the pedal, but mine does not make any sound so matter what or when.

sevenstar · 10-25-2009, 01:03 PM

You might have a problem if yours makes no sound at all.l I have after market piping

guitaraholic · 10-25-2009, 01:06 PM

There is a bleed hole in the stock BOV, So its actually made to leak a little bit, why I have no idea. I tapped mine and fit in a set screw, boost builds faster now. I'm going to reverse it here shortly and turn it into a pull style when I get the hose thing figured out.

sevenstar · 10-25-2009, 01:26 PM

You might have a problem if yours makes no sound at all.l I have after market piping

dongoesby · 10-25-2009, 05:32 PM

Quote:

Originally Posted by sevenstar

You might have a problem if yours makes no sound at all.l I have after market piping

so you are saying it supposes to make a sound?

well, i just got the swap done with everything stock. Recently, I hear a tiny sound when I let go the throttle. I'm really not sure how should it sound. Do you or anyone got a sound clip for stock bov?

sevenstar · 10-25-2009, 06:27 PM

Quote:

Originally Posted by guitaraholic

There is a bleed hole in the stock BOV, So its actually made to leak a little bit, why I have no idea. I tapped mine and fit in a set screw, boost builds faster now. I'm going to reverse it here shortly and turn it into a pull style when I get the hose thing figured out.

can you post a pic of this bleedhole thing?

Def · 10-25-2009, 06:53 PM

Stock bypass/blow off valve sucks. Mine would build boost about 300-400 RPM later than with one that would hold shut.

I adapted an aluminum "Bosch style" bpv to the stock location and love it. No surging under partial throttle boosting(like modulating throttle in the middle of a corner), and has adjustable springs so you can fine tune how much seat pressure it has. Has o-rings all over so it doesn't leak. I just had to epoxy on a slightly larger tube for the stock sized bov/bpv inlet hose to be secure(it's a 1" inlet/outlet, stock has a bigger inlet - ~38mm IIRC).

dongoesby · 10-25-2009, 08:23 PM

Quote:

Originally Posted by Def

Stock bypass/blow off valve sucks. Mine would build boost about 300-400 RPM later than with one that would hold shut.

I adapted an aluminum "Bosch style" bpv to the stock location and love it. No surging under partial throttle boosting(like modulating throttle in the middle of a corner), and has adjustable springs so you can fine tune how much seat pressure it has. Has o-rings all over so it doesn't leak. I just had to epoxy on a slightly larger tube for the stock sized bov/bpv inlet hose to be secure(it's a 1" inlet/outlet, stock has a bigger inlet - ~38mm IIRC).

could you give more in-depth info on the "Bosch style" bpv? Where can we get it, and how does it work comparing to stock bov? Is it a complete replacement?

I'm continously searching for a recirculate valve that can replace my stock recirculate valve, because I constantly thinking mine does not work.

lazysk8er2 · 10-25-2009, 08:29 PM

possibly get a new pipe and put a greddy on or an hks or even a synchronic bov

guitaraholic · 10-25-2009, 08:50 PM

It's inside the BOV itself. It is a small hole about 3-4 mm in diameter. Why its there I don't know. But connects the High and Low pressure side. You can physically blow from one side to the next by mouth. I blocked it off, and now my turbo is spooling at like 2.5k hell, it almost spools when I don't want it to. Its not that hard to take apart the BOV, its 3 screws, then just tap it with a 10mmx24 tap, and put in a set screw (put some paint on the screw so it doesn't come out) and you're done. No more leaks. Flip the hoses (will need to adapt the sizes) and now its a pull instead of a push style (will be doing that in the near future)

RbPowered240z · 10-25-2009, 09:34 PM

I dont mean to thread jack, but i just put on my blitz bov and supposedly the bov release's on high rpms, but i notice everytime that theirs a hissing sound before it goes off, i cheacked my boost gague and its right??

anyone know what this might be?

RbPowered240z · 10-26-2009, 04:03 AM

bump!!!!!!

sevenstar · 10-26-2009, 02:54 PM

yeah i got the hissing sound too, on high boost.

RbPowered240z · 10-26-2009, 07:59 PM

anyone????????

Tom25666 · 10-26-2009, 08:31 PM

the stock smic bov recirc'ed is basically silent

Def · 10-27-2009, 10:08 AM

Quote:

Originally Posted by dongoesby

could you give more in-depth info on the "Bosch style" bpv? Where can we get it, and how does it work comparing to stock bov? Is it a complete replacement?

I'm continously searching for a recirculate valve that can replace my stock recirculate valve, because I constantly thinking mine does not work.

Bosch Turbo Bypass Valve for Audi Porsche VW Diverter:eBay Motors (item 360102436125 end time Nov-22-09 18:15:32 PST)

Like I said, it's not a drop in replacement. I epoxied on a 1.375" tube I beaded for the inlet, or you could get a reducing coupler - something. The inlet/outlet of the stock BPV is ~1.3"/~1"(I think, been a while since I messed with a stock one), the Bosch style one is 1"/1" so you have to make the inlet bigger. The packaging is similar. I've got mine in the stock location on my GReddy VSPL IC kit recirculating to an aluminum intake pipe I fabbed up.

Like I said, it works great, and you can adust the spring inside for whatever boost you're running and vacuum you draw at idle. I have the middle one in and it works just fine. No more compressor surge like the HKS SSQV was giving me on partial throttle lifts, and much faster response.

dongoesby · 10-28-2009, 10:58 PM

Quote:

Originally Posted by Def

Bosch Turbo Bypass Valve for Audi Porsche VW Diverter:eBay Motors (item 360102436125 end time Nov-22-09 18:15:32 PST)

Like I said, it's not a drop in replacement. I epoxied on a 1.375" tube I beaded for the inlet, or you could get a reducing coupler - something. The inlet/outlet of the stock BPV is ~1.3"/~1"(I think, been a while since I messed with a stock one), the Bosch style one is 1"/1" so you have to make the inlet bigger. The packaging is similar. I've got mine in the stock location on my GReddy VSPL IC kit recirculating to an aluminum intake pipe I fabbed up.

Like I said, it works great, and you can adust the spring inside for whatever boost you're running and vacuum you draw at idle. I have the middle one in and it works just fine. No more compressor surge like the HKS SSQV was giving me on partial throttle lifts, and much faster response.

Well I'm comparing it to my stock sr20 recirculate valve. Do you think it will work?

After reading the link, I noticed that it is an upgrade for stock rubber bov and those that are using diagrams. I know our factory SR ones are metal, but I'm not sure if it is a diagram type. Could you confirm on that?

As for a mulfunction bov, besides leak, what other symptoms would it gives? My vacuum looks fine at idle (-8psi), and the car drives fine, no lost power between shift. It just makes no sound. Is it operating fine?

Def · 10-29-2009, 09:03 AM

YES IT WILL WORK IN PLACE OF THE STOCK RECIRC VALVE WITH SOME MINOR MODIFICATION!!!!!

I don't know if anything is wrong with your stock BOV, I'm not a psychic. Take it out and inspect it.

10-21-2009, 11:38 AM	#1
sevenstar BANNED Join Date: Sep 2009 Location: japan. california Age: 51 Posts: 156 Trader Rating: (1) Feedback Score: 1 reviews	stock blowoff valve leaks? I am wondering if the stock blowoff valve is prone to leak at 12psi? has anyone noticed their car hissing under boost over stock psi? i have not pressure tested the stock bov yet, but after reading your responses might have to

10-25-2009, 06:53 PM	#9
Def Post Whore! Join Date: Apr 2004 Location: Houston, TX Posts: 2,701 Trader Rating: (16) Feedback Score: 16 reviews	Stock bypass/blow off valve sucks. Mine would build boost about 300-400 RPM later than with one that would hold shut. I adapted an aluminum "Bosch style" bpv to the stock location and love it. No surging under partial throttle boosting(like modulating throttle in the middle of a corner), and has adjustable springs so you can fine tune how much seat pressure it has. Has o-rings all over so it doesn't leak. I just had to epoxy on a slightly larger tube for the stock sized bov/bpv inlet hose to be secure(it's a 1" inlet/outlet, stock has a bigger inlet - ~38mm IIRC). __________________ S13 Hatch - Goes around tracks quickly DEFSPORT

10-29-2009, 09:03 AM	#20
Def Post Whore! Join Date: Apr 2004 Location: Houston, TX Posts: 2,701 Trader Rating: (16) Feedback Score: 16 reviews	YES IT WILL WORK IN PLACE OF THE STOCK RECIRC VALVE WITH SOME MINOR MODIFICATION!!!!! I don't know if anything is wrong with your stock BOV, I'm not a psychic. Take it out and inspect it. __________________ S13 Hatch - Goes around tracks quickly DEFSPORT

10-21-2009, 12:03 PM	#2
g6civcx Post Whore! Join Date: Apr 2004 Location: Virginia, USA Posts: 5,764 Trader Rating: (5) Feedback Score: 5 reviews	For a 10-15 year old engine, I wouldn't pull it pass the stock piping to have a leak somewhere.

10-21-2009, 09:05 PM	#3
dongoesby Zilvia Addict Join Date: Mar 2007 Location: San Francisco Age: 38 Posts: 756 Trader Rating: (17) Feedback Score: 17 reviews	i just got my swap done with stock piping and stock recirculating valve. And it does not make any sound (pssh) under boost. I'm not sure if it suppose to make a sound when you let go of the pedal, but mine does not make any sound so matter what or when.

10-25-2009, 01:03 PM	#4
sevenstar BANNED Join Date: Sep 2009 Location: japan. california Age: 51 Posts: 156 Trader Rating: (1) Feedback Score: 1 reviews	You might have a problem if yours makes no sound at all.l I have after market piping

10-25-2009, 01:06 PM	#5
guitaraholic Zilvia Junkie Join Date: Jun 2006 Location: Spanish Fort, AL Posts: 430 Trader Rating: (0) Feedback Score: 0 reviews	There is a bleed hole in the stock BOV, So its actually made to leak a little bit, why I have no idea. I tapped mine and fit in a set screw, boost builds faster now. I'm going to reverse it here shortly and turn it into a pull style when I get the hose thing figured out.

10-25-2009, 01:26 PM	#6
sevenstar BANNED Join Date: Sep 2009 Location: japan. california Age: 51 Posts: 156 Trader Rating: (1) Feedback Score: 1 reviews	You might have a problem if yours makes no sound at all.l I have after market piping

10-25-2009, 08:50 PM	#12
guitaraholic Zilvia Junkie Join Date: Jun 2006 Location: Spanish Fort, AL Posts: 430 Trader Rating: (0) Feedback Score: 0 reviews	It's inside the BOV itself. It is a small hole about 3-4 mm in diameter. Why its there I don't know. But connects the High and Low pressure side. You can physically blow from one side to the next by mouth. I blocked it off, and now my turbo is spooling at like 2.5k hell, it almost spools when I don't want it to. Its not that hard to take apart the BOV, its 3 screws, then just tap it with a 10mmx24 tap, and put in a set screw (put some paint on the screw so it doesn't come out) and you're done. No more leaks. Flip the hoses (will need to adapt the sizes) and now its a pull instead of a push style (will be doing that in the near future)

10-25-2009, 09:34 PM	#13
RbPowered240z BANNED Join Date: Jul 2009 Location: los angeles Posts: 233 Trader Rating: (1) Feedback Score: 1 reviews	I dont mean to thread jack, but i just put on my blitz bov and supposedly the bov release's on high rpms, but i notice everytime that theirs a hissing sound before it goes off, i cheacked my boost gague and its right?? anyone know what this might be?

10-26-2009, 04:03 AM	#14
RbPowered240z BANNED Join Date: Jul 2009 Location: los angeles Posts: 233 Trader Rating: (1) Feedback Score: 1 reviews	bump!!!!!!

10-26-2009, 02:54 PM	#15
sevenstar BANNED Join Date: Sep 2009 Location: japan. california Age: 51 Posts: 156 Trader Rating: (1) Feedback Score: 1 reviews	yeah i got the hissing sound too, on high boost.

10-26-2009, 07:59 PM	#16
RbPowered240z BANNED Join Date: Jul 2009 Location: los angeles Posts: 233 Trader Rating: (1) Feedback Score: 1 reviews	anyone????????