bov question

[slidin40]

Ok I have sreached and havent got the answer i want. I have a rb20det swap in my s13. I had a ricirc stock bov on it and it never gave the "flutter" "compression surge". I bought a legit hks ssqv black edition installed it after getting the flange welded on, it started giving me that Noise I explained. The werid thing is that when i hook both of then up (just to see what happens) I "T" the bov's it doesnt make the noise. I uploaded pics so u can see if where it was installed is causing that "flutter". thanks in advance
http://i1251.photobucket.com/albums/hh552/slidin40/build/stockbov2.jpg
http://i1251.photobucket.com/albums/hh552/slidin40/build/hks1.jpg
http://i1251.photobucket.com/albums/hh552/slidin40/build/hks2.jpg
http://i1251.photobucket.com/albums/hh552/slidin40/build/stockbov.jpg
The noise is coming from here...
http://i1251.photobucket.com/albums/hh552/slidin40/build/maf.jpg

[4x4le]

If its brand new give it a day or so. I have seen a few ssqvs surge (not open enough or fast enough) when brand new but they usually calm down after a drive or 2.

[Kingtal0n]

The SSQV may never give the same performance as the OEM bypass.

Push type bypass valves, such as your OEM unit, are generally more responsive- due to their nature, as boost pressure helps to push them open when vacuum is applied above the diaphragm during throttle closure. The SSQV has no such assistance from boost pressure, from what I have read, and therefore tends to be less responsive, giving you the surge you describe.

Now, I have had SSQV that work great and give very little surge on RB25 engines. They are installed on the hot-pipe. Cold pipe installations tend to give surge more readily... and your bypass appears to be on the cold-pipe. Sometimes it is simply a vacuum signal issue, you can try running a dedicated vacuum source (do not T the source to ANYTHING ELSE) and see if that helps. Make sure the vacuum line is a good diameter and has no leaks.

My opinion for this situation- if a dedicated proper diameter vacuum line does not help- run them both. The OEM unit will do it's job, the HKS will make noise. The only problem is- if you turn up the boost pressure, the OEM unit may leak. But you have an RB20... you should keep the boost pressure as low as possible, regardless of the modifications.

[jacobs13]

My hks does the same thing, usually only in higher boost. Like Kingtalon said, make sure you have a good vacuum source. Whenever I had mine T'd, it was significantly worse.

[4x4le]

But you have an RB20... you should keep the boost pressure as low as possible, regardless of the modifications.

:rofl:

I really dont even know what to say to you sometimes.
I can only hope to have your wisdom someday.

[slidin40]

Thank u guys. Where would be a good (best) vacuum source? I do have it on the cold side. And yes it's a rb20. Good eye

[slidin40]

I have the vacuum line for the hks where the factory on was. And the hose is the same size as the port on the bov not the size of the vacuum port.

[Kingtal0n]

:rofl:

I really dont even know what to say to you sometimes.
I can only hope to have your wisdom someday.

One day, maybe.

[4x4le]

http://www.discounthotelbook.com

much appreciated

-bump-

Zilvia needs to change up the registration process......