compressor surge?

[CSX153]

when i first put on my hks ssqv, it sounded like it should. fast foward a few months and it kinda sounds like its surging. so i swapped in another ssqv to see how it would sound, same thing, if not worse. i've tried adjusting the screw on top, which doesnt seem to do anything. im using vacuum from the vacuum block, so i tried using the vac from the tb and even that made it sound like its wasnt even working at all. i pulled apart the bov to see if maybe something was wrong internally, but it seemed to be in working order. im not sure what to try next. any ideas?

[mark]

there are two nipples at the T, did you try both of them. one of them will never open the bov.

how much vacuum are you getting on your car, and when.

[CSX153]

18 at idle, havent looked at what it is when i let off. keep in mind, this is under normal driving. 0 vac or maybe 1-2lbs. under full boost, i guess it sounds ok.

and its the smaller fitting that i was using on the tb

[mark]

sounds like bov too tight?

[CSX153]

18-20 vac, when I let off. I'll try loosening it.

[CSX153]

loosened it, didnt help much.

[Dusty_Duster]

Sounds like your BOV broke. Get a different brand other than HKS. I recommend TiAL.

[cordes]

Does the valve open ever so slightly when you open the TB some and then let it slam closed? That should cause a bit of a spike in your vac opening up the valve just a little bit. If it isn't opening you need to loosen it up some.

[Dusty_Duster]

Does the valve open ever so slightly when you open the TB some and then let it slam closed? That should cause a bit of a spike in your vac opening up the valve just a little bit. If it isn't opening you need to loosen it up some.

I'm not so sure that would work on an HKS SQV. The design on those units is pretty weird.

[cordes]

I'm not so sure that would work on an HKS SQV. The design on those units is pretty weird.

That's how I have my old style one setup and it has functioned flawlessly for 6-7 years now.

[CSX153]

Sounds like your BOV broke. Get a different brand other than HKS. I recommend TiAL.

ya but i said i switched it with a known working one, and it does the same thing.

[Dusty_Duster]

ya but i said i switched it with a known working one, and it does the same thing.

It wouldn't surprise me if two HKS SQVs were both broken...

Where is your BOV located on the intercooler pipes? Is the vacuum line ran directly to the intake manifold?

[CSX153]

The other hks works and sounds fine on the other car, so I doubt it. The bov is on the cold pipe, maybe 8" from the tb. And the vac line is coming off of the vac block on the intake manifold.

[Dusty_Duster]

What is your idle vacuum with the car in gear?

[CSX153]

5spd, 19" in neutral. 19-20 when i let off

[Dusty_Duster]

If the BOV isn't opening, it might not be seeing vacuum properly when you let off the throttle. Hook a boost gauge to a tee on the line going to the the BOV and make sure it's seeing vacuum immediately after closing the throttle. Check for vacuum leaks, as well.

[CSX153]

Put a gauge on it and it's 15 at idle, 20 when I let off.

[OmniLuvr]

15 is the border line low for some bov's to work properly, i had 14 and my greddy type-s didnt want to work, only one i got to work correctly at the vac. level was the gen1 mitsu. maybe you can remove the back of the hks unit, remove the spring and either cut some coils off or find a softer one?

[CSX153]

thats an interesting concept, but seems risky?

[cordes]

15PSI at idle? You don't have an auto trans do you? Is that reading in P/N or in gear if you do?

15PSI would be very low vac for anything but a very radical cam. If you don't have a radical cam, auto trans in gear, or some such, I would suggest that the cam timing is off a tooth.