I just installed my greddy type s bov and when I go full throttle it holds boost up to 21 psi but then it starts to flutter and then releases all the pressure as if I let off the throttle. I dunno what psi the previous owner was running. Do I need to tighten the adjustment bolt to make it stiffer to hold more boost? I'm running 22-23 psi right now, but I'm gonna raise it to 28+ psi within the next month or 2. Also I read that the bov will flutter a lot if I don't connect the lower vacuum port. Would it help if I capped it off or something?

 

don't cap off the lower vacuum port. You can connect it to another pressure source to better driveability. You may have it setup too stiff. The only way to know if it's leaking is if you pressure test your system and you hear leaks at the bov.(You may have a bad diaphragm.)

 

if it's leaking under boost, tigten it, that's putting more spring force against the piston to keep it closed.

 

It sounds like typical bov flutter which is inherent of using the stock turbo.

 

Yeah I think I fixed it. It seemed like the bov was too soft so I tightened it and drove it around. Then it seemed too hard so I loosened it a little and now it feels great. It holds 23 psi perfectly. I still feel a slight flutter, but it's just like the stock bov. I'll see how it feels on the freeway. I still wanna check the diaphragm and see if there are any rips or anything. Would it be okay to connect the lower vacuum port to the maf pipe?

 

NO

 

good deal

 

Lower vaccum goes to IC piping before throttle plate. It helps the valve open quicker and more fully. But from personal experience evos work better with the lower port just open to the atmosphere. I guess running it to the maf pipe would be the same thing. Go for it.

 

i thought i adjusted it properly, but on the way home from work i realized that it would only hold boost at full throttle. it wouldn't hold it during partial throttle. when i had the throttle 1/4 open my boost would only go up to 15 psi and then start flutterring like crazy. i just finished doing the single spring mod. i figured it would be okay to do since i'm running 23 psi right now. do you think i can run 28 psi with the single spring mod? i'm increasing my boost to 28 psi once i install my meth kit and fp green.

 

I think it's time to get the APS twin vent bov and move on with the fun stuff

 

APS, though may be a "ricer" BOV to some people works VERY well. Being twin vent does nothing but make more noise, BUT it's one of the best performing aftermarket BOV's on the market. Holds plenty of boost, recirculates, sounds like stock at partial boost (louder at full boost since it's tiwn vent) and great driveability. I defiantly recommend it if you insist on running an aftermarket BOV. I've had zero problems with my APS.

The ONLY reason I went with APS was because it was given to me and I run higher than stock boost. Turn down a FREE BOV, especially one of the best in the Evo market? Uhhhh no! Haha If I didn't go with APS, I would have went with a stock IX BOV.

 

i liove the greddy type s

 

Type S w/ single spring works fine. I had mine holding 23+psi at redline from a 28psi spike.

 

I hated the greddy, No matter what I did.Bought an APS and its perfect

 

how many times did you turn the adjustment bolt? i've tried 3 turns, 6 turns, 8 turns, and now i'm at 10 or 11 turns (havent tried driving it yet though). it holds 23 psi at full throttle for about 3-5 seconds and then starts to flutter or something. and it always flutters when i try to hold boost at part throttle.