surging issues and the BOV seems to flutter

[CamaroKiller]

I have a 98 GST with a 16g turbo, GReddy FMIC, GReddy Type-S BOV, MBC, and Autometer Boost gauge. I have the MBC tapped into the J-pipe. And the lower nipple on the BOV is unconnected. I'm new to the DSM worls and have a few things I'm unsure of. My problem is this. My turbo has some surging issues and the BOV seems to flutter. Soon after buying the car I realized that the screw in the top of my BOV was stripped out. So I retapped it. I tried to reset the BOV to where I thought it should be but I really don't know. I've done a lot of research on setting a BOV. My question is this is it better to do the single spring mod, or just try to adjust it according to "Wobble's guide to setting up your BOV correctly" using both springs? Any help you guys can provide me will be greatly appreciated. Sorry for the long post.

Thanks,
Seth

 

[b00stedtalon2]

For adjusting the BOV, I would start with making the spring tight than take it for a test drive. Most likely you will hear the "fluttering" noise which is compressor surge. Keep loosening the spring until it goes away.

 

[Boost92awd]

I have a greddy type s on my car and have both springs in it and the lower nipple disconnected. The only good place to connect the 2nd nipple is to the UICP. I'm on stock boost and I'm not having any problems at all with the BOV. Have you checked for boost leaks after your retapped your BOV?


As for setting your BOV, thats all I did was more of a test and tune. Set it and drive around and listen to it go off and then make changes from what you hear. I found this is the best way to do it.

 

[CTP]

First off, when you say surge do you mean real surge during acceleration or surge during throttle closing because the BOV isn't venting correctly?

As for the BOV setting, I've beaten this to death a few million times in the past, but here we go again...

The setting on GReddy BOV's is for VACUUM. It has nothing to do with how much boost you're running, the BOV leaking, or what you want it to sound like. If you don't believe me (and no one ever does) call GReddy and ask them. Motors that pull high vacuum need the spring tightened down to prevent the BOV from hanging open at idle/low throttle. This is all the adjustment is for. It has nothing to do with your BOV leaking.

Start with the screw all the way out. Let the car idle and tighten the screw until the BOV isn't open. That's it, you're done. I have my RS set at full soft (screw is only on enough to seal the hole) and I run 27psi with no leaks.

 

[CamaroKiller]

It actually does surge under hard acceleration. If this is not related to the BOV what typically causes this. Like I said I'm new to the whole turbo scene so any help is appreciated.

Thanks,
Seth

 

[95CarbonEclipse]

First off, when you say surge do you mean real surge during acceleration or surge during throttle closing because the BOV isn't venting correctly?

As for the BOV setting, I've beaten this to death a few million times in the past, but here we go again...

The setting on GReddy BOV's is for VACUUM. It has nothing to do with how much boost you're running, the BOV leaking, or what you want it to sound like. If you don't believe me (and no one ever does) call GReddy and ask them. Motors that pull high vacuum need the spring tightened down to prevent the BOV from hanging open at idle/low throttle. This is all the adjustment is for. It has nothing to do with your BOV leaking.

Start with the screw all the way out. Let the car idle and tighten the screw until the BOV isn't open. That's it, you're done. I have my RS set at full soft (screw is only on enough to seal the hole) and I run 27psi with no leaks.

This may sound stupid, but... how can you tell if the BOV is open during idle? I'm just assuming that you have to listen for the sound of air rushing through the BOV, but that's just an assumption.

 

[CTP]

It actually does surge under hard acceleration. If this is not related to the BOV what typically causes this. Like I said I'm new to the whole turbo scene so any help is appreciated.

Thanks,
Seth

That's definintely not normal and also has nothing to do with the BOV. At what RPM's and throttle positions does it surge and what kind of boost are you seeing at the time?

This may sound stupid, but... how can you tell if the BOV is open during idle? I'm just assuming that you have to listen for the sound of air rushing through the BOV, but that's just an assumption.

Simply looking in it would be the main way, or stick your finger in there and feel if the valve is slightly open, or put your hand over it and see if it's sucking air.

 

[95CarbonEclipse]

Simply looking in it would be the main way, or stick your finger in there and feel if the valve is slightly open, or put your hand over it and see if it's sucking air.

Ah... without the recirc tube installed, duh!

 

[CTP]

Ah... without the recirc tube installed, duh!

Haha, yup. Just remember to plug the hole in the intake or you probably won't even get the car started.