Hi everyone so i have a issue that isn’t entirely an issue, so i bought 2 HKS ssqv bovs, that are genuine hks part. And i took my old recirc valves off, capped the recirculating ports, and installed my new hks bovs, i was really excited to hear the high pitched hks sound, but to my surprise they kinda sound the same but only a tad bit louder. Its only a flutter and not a high pitched sound. I did all the research i can but i cant seem to find out why they don't make the sound, people have had them break, and leak, and cause a surge, some say that their car wouldn’t idle with them, but mine acts just fine, it actually seems to run better. My only guess is not enough boost, because im only pushing about 8-9lbs of boost. Every other 300zxtt iv seen on YouTube and post with a hks bov sound high pitched, but mine just seems to flutter a tiny bit. I checked for leaks, and pulled up the step by step install from hks, and everything seems to be on right.

Im just confused , and a little concerned for my turbo, im worried that since it doesn’t make the high pitched noise that it isn’t working right, and might can hurt my turbo.

But just to clarify it makes boost just fine, and seems to run just fine. Thanks for reading and I would like to know yalls opinions.

Also i have pictures and videos but im new to this and dont know how to send them haha

If it's fluttering, the air is being pushed back to the turbo when you close your throttle, so your BOVs are not blowing off, hence no SSQV sound. Double check your install.

Assuming you are still running with a stock MAF setup then this might be of interest to you:

http://www.twinturbo.net/nissan/300zx/forums/general/view/2421113/I-do-not-recommend-blow-off-valves-on-the-Z.html

14 hours ago, Peage said:

If it's fluttering, the air is being pushed back to the turbo when you close your throttle, so your BOVs are not blowing off, hence no SSQV sound. Double check your install.

I will triple check it, and smoke test it to see if im leaking anywhere, iv doubled checked them and they seem fine, the vacuum lines seem to be nice and tight so im not sure what the issue is.

10 hours ago, AndrewG said:

Assuming you are still running with a stock MAF setup then this might be of interest to you:

http://www.twinturbo.net/nissan/300zx/forums/general/view/2421113/I-do-not-recommend-blow-off-valves-on-the-Z.html

Iv seen this forum before, but my issue isnt that its running rich, its that the Hks bov is not making its signature sound. Im am running a stock maf setup, but i do have a cold air intake on the car.

If the stock boost gauge is what you’re looking at, it’s a bit optimistic. Check your ECU for safety boost. If you’re only making 7psi I’d not be surprised.

My car runs on Baileys. At partial boost they chirp. That classic whoosh sound only occurs when I’m on the boost properly.

1 minute ago, Stephen said:

If the stock boost gauge is what you’re looking at, it’s a bit optimistic. Check your ECU for safety boost. If you’re only making 7psi I’d not be surprised.

My car runs on Baileys. At partial boost they chirp. That classic whoosh sound only occurs when I’m on the boost properly.

I have a stock gauge and a boost gauge on my console, they are both reading the same lbs, and i usually run about 8-10 lbs of boost, 10 being on a cold day. Im just a little bummed out that they aren’t making the hks noise they should be..