Greddy BOV possible boost leak?

[mieszkoj]

Hi. I have a question, i just installed my greddy type S BOV on a 98 eclipse gst. When my boost goes to about 5 to 10 psi, the BOV makes a funny output noise, like jitter noise. But when it boosts to 14+ psi it makes a nise "pppfewwwwwww" noise.. under the 14psi boost, it makes jittering sound, sounds like the valve rattles. Any idea? Could it be a leak in the boost?

Question 2: how do you adjust the greddy bov? make the bolt really loose, or tighten it with your fingers? To tight might blow the head gasket?

- Thank you for all reading my post.

 

[Boost95]

Sounds like compressor surge from what you posted. As far as at low boost levels its normal to have surge. Try to loosen it a little bit. To adjust it, just loosen the screw and turn the bolt in or out with an allen key. Dont worry about adjustments to your BOV blowing your head gasket Good Luck

 

[kottyking]

Adjust the bov to harder. You'll have to drive around a few times to get it right.

 

[mieszkoj]

thanks mike.. The screw is almost to the top. its as loose as it can be.. hehehe. So i dont know its set to soft.

 

[mieszkoj]

I tried to adjust the bolt to harder, and softer, still same problem.. I dont get as much surge when its bit tight, but still its pretty bad hehehe. Can u turn it even more harder? i tightened the bolt with my fingers. Mike you said to try tightening or loosening the allen bolts, you are talking about the 4, 5 allen bolts that are on the purple cap?

 

[ericbev]

Adjust the bov to harder. You'll have to drive around a few times to get it right.

Negative. If he is experiencing compressor surge at low throttle releases (which I am 99% sure he is) then you have to loosen your bov, not tighten (harden) it.

Is that a real greddy bov or is it one of those e-bay knockoffs? It is hard to tell by the picture. Also, you are not recirculating in your picture, is there any reason why not?

Here is one of my previous posts from another thread.

How do I adjust my BOV correctly?

The "harder" the setting (the deeper the adjustment screw), the less prone the valve will be to being blown open and the greater the change in pressure needed to open it. Set too soft, the valve could possibly be blown open under high boost. Set too hard, the valve may flutter or not open at all. Any fluttering from too hard of a setting will be most noticeable during light throttle changes since there is only a small change in pressure on either side of the valve. The more you let off the gas and/or the more quickly you let off, the greater/sharper the change in pressure and the increased ability for the valve to open flutter-free. In short, for the very least potential valve flutter, adjust the spring as light as possible without it being blown open for your setup and boost level. The fluttering sound you will hear is also known as compressor surge and is bad news. So basically, loosen it up enough that you dont hear fluttering at very low throttle releases, but make sure its hard enough that it doesnt start blowing off boost. It shouldnt be hard to find this "neutral" spot. The fulttering is very noticeable and so is the valve blowing off boost. Go on a backroad where its you and the road (nice and quiet), carry the allen wrench and box wrench with you, and play with it till you are satisfied

What is compressor surge?

Compressor surge is when the air pressure after the compressor is actually higher than what the compressor itself can physically maintain. This condition causes the airflow in the compressor wheel to back up, build pressure, and sometimes stall. In cases of extreme surge, the thrust bearings of the turbo can be destroyed, and will sometimes even lead to mechanical failure of the compressor wheel itself. It is commonly described as a chuffing or fluttering sound depending on the severity. You will know it when you hear it

 

[97GSTJake]

I have tightened my Greddy with my fingers as well, and thought that i had it on tight enough, but it was knocked loose from driving only 5 minutes afterwards. Make sure you use a wrench to tighten that thing down good, not your fingers. And dont tighten it to hard, the tops are known to strip out easily....

 

[Newlogics]

The key question is if your BOV makes those sounds while you're under constant throttle (that would indicate that your BOV is leak, possible damaged diaphragm.) or when you back of from the throttle (in that case, you need to adjust set screw).

 

[mieszkoj]

ericbev :: yes i am experiancing compressor surge at low throttle releases. And yes it is the ebay bov The reason why i am not recirculating back is for more sound.. When i do tighten the bolt very well, so you cant loosen it up with your fingers, the surge is gone. But shouldint this be the other way around? and at 14+ psi ill get the nice Woosh.. But i heard having that bolt tight to much is no good? POssibly blowing ## head gasket?? thats what i read on some forums... Also the only allen bolts that i can see on the bov is on the purple cap, you can adjust those bolts as well???

 

[mieszkoj]

The key question is if your BOV makes those sounds while you're under constant throttle (that would indicate that your BOV is leak, possible damaged diaphragm.) or when you back of from the throttle (in that case, you need to adjust set screw).

--- when i am under constant throttle no surge, everything is okay and smooth.. its only when i release from low boost it makes the surge...

 

[ericbev]

ericbev :: yes i am experiancing compressor surge at low throttle releases. And yes it is the ebay bov The reason why i am not recirculating back is for more sound.. When i do tighten the bolt very well, so you cant loosen it up with your fingers, the surge is gone. But shouldint this be the other way around? and at 14+ psi ill get the nice Woosh.. But i heard having that bolt tight to much is no good? POssibly blowing ## head gasket?? thats what i read on some forums... Also the only allen bolts that i can see on the bov is on the purple cap, you can adjust those bolts as well???

Sound schmound. My recirculated Type-S can be heard from a block away. I cant really imagine it being any louder than it already is. I would really advise you to recirculate that thing to avoid driveability issues among other things.

Here is a thread about those ebay units.

http://www.dsmtuners.com/forums/showthread.php?t=215445&highlight=type-s,+ebay

I know "You get what you pay for" is an overused cliche on this site, but it holds water in alot of respects, especially when we are talking about knockoff ebay parts. Paying 25 bucks for a brand new part that normally costs 150 raises some immediate questions.

Loosening (softening) the bov, is how you get rid of surge, not tightening it. Yes it should be the other way around. Having the screw tightened too much will lead to the premature destruction of your turbo, not blowing a headgasket.

The other allens on the top of the bov hold the cap to the body. Dont mess with these. They having nothing to do with the adjustment you are trying to get.

 

[mieszkoj]

DAMN ebay sellers ..

what is the best BOV. Meaning in the sound it gives out? any recommendations?

 

[Black94DSM]

Take the top of the BOV off and take out the inner spring of the two.....when you put it back together put a thin bead of silicone down around the bolt holes. Then do the steps of finding where it will be best at(driving around and tighten/loosen the allen screw).

Good luck. And yes you do get what you paid for. Recirculate please.

 

[ericbev]

DAMN ebay sellers ..

what is the best BOV. Meaning in the sound it gives out? any recommendations?

All bovs sound fine to me. I didnt buy mine for the sound. All of them sound a little different. I would worry about getting one that operates and adjusts properly instead of worrying about what it sounds like.

Take the top of the BOV off and take out the inner spring of the two.....when you put it back together put a thin bead of silicone down around the bolt holes. Then do the steps of finding where it will be best at(driving around and tighten/loosen the allen screw).

Good luck. And yes you do get what you paid for. Recirculate please.

I am not sure if the ebay units utilize a twin spring design like the real greddy unit. The "single spring mod" might not apply.

 

[zippyshoe]

Take the top of the BOV off and take out the inner spring of the two.....when you put it back together put a thin bead of silicone down around the bolt holes. Then do the steps of finding where it will be best at(driving around and tighten/loosen the allen screw).

Good luck. And yes you do get what you paid for. Recirculate please.

Here is some more information on this modification: http://www.evomoto.com/tech_info.php?tPath=1&tech_id=7

 

[mieszkoj]

Thank you guys for the info. I decided to take out the inner spring from the bov. Now everything is working as it should be. But i came across one small annoying problem. At low throttle discharge, the bov will whistle. Any way of eliminating that? Possibly putting in a lower tension inner spring?

 

[Black94DSM]

Thank you guys for the info. I decided to take out the inner spring from the bov. Now everything is working as it should be. But i came across one small annoying problem. At low throttle discharge, the bov will whistle. Any way of eliminating that? Possibly putting in a lower tension inner spring?

Awsome glad to hear you got everything working now. The wistle is the trademark Type-S sound. You will not be able to get rid of it.

 

[mieszkoj]

Ahhh. Thank you very much Bob for helping a newb here . I tried to recirculate the bov back to the turbo, but the wooosh sound is gone.. can barly hear it. Even not having it recirculate back to the turbo, will it damage anything?? Once again thank you guys for the help, much appreciated...

 

[kenamond]

Even not having it recirculate back to the turbo, will it damage anything??

Read this.

 

[2GeNTSi]

Ok so I just installed the greddy type-s on my car and it sounded as it did when it was on the vr-4 we had (I describe it as fireworks being shot in the air or like a laser gun ) and noticed that above 10hg but below 0psi, it would make an audible noise that I thought was a leak. I hardened it a bit from how it was adjusted on the vr-4 (a couple revolutions) and it helped maybe a little.

Is the adjusting screw adjustable through all those threads or what? I still have quite a bit of play if so.