machron1

iTrader: (1)

That is unlike any flutter I've ever heard. I highly doubt it is something normal. It sounds as if pressure is never applied to the other side of the BOV keeping it open...but for some reason my browser can't see video only audio...

Edit: I was just looking at your pictures. Source the MBC air supply from a different place than your BOV. When air is bled out to your wastegate from that line by your MBC, it creates a pressure differential between the top and bottom of the BOV letting it open. Basically you are having the opposite of compressor surge. Your BOV is opening too easily as opposed to not easily enough. This is why lowering the boost to close to the pressure threshold of the WGA spring helps get rid of this problem. When the system is closed such that no air is making it to the WGA, your BOV is equalized. However, the more pressure that builds, the more the valve tries to hold the wastegate open, the more air is bled away from your BOV, and the less pressure it has holding the valve closed. Then when the wastegate opens, less pressure is made by the turbo, so less pressure is pushing the BOV open, so then the air can start going to your engine again, which makes more boost, repeat repeat etc. However, as boost comes on even harder, the manifold pressure is high enough to supply that little line with enough pressure to hold your WGA open and keep the BOV pressurized, not to mention the WGA pressure is not fluctuating as much as it was during transient boost levels, and is now holding steady, so there is less need to vent air back through the MBC while opening-closing-opening the wastegate. Remember at part throttle the throttle body butterfly is slightly closed so as the engine revs there is likely to be fluctuations in the pressure differential of the air on either side of it.

Hope that helps!

Edit #2: If what I said above isn't obvious, here is what I recommend you do:

• Run a dedicated line from the Intake Manifold to your BOV with no T.
• Run a line T'd off of another line running off the intake manifold to your MBC, or drill a nipple into your lower intercooler pipe and use that air supply.
• Problem solved.

BigBADGSX

iTrader: (11)

glad to see you fixed it. I could tell by your previous posts that it was pissing you off big time.

WEVO

iTrader: (5)

Hi, drewblueeye, not trying to hijack your thread. But I'm experiencing similar problem with my bov as well. Whenever I go WOT with my GFB bov, it would go off with three chew chew chew sound. It's not the regular partial throttle fluttering, it's a distinct sound. It has never happened before until recently. Sounds like my bov is leaking or something, or maybe I have a boost leak and it's causing the bov to go off earlier? I'm not too sure what's going on, I just need some help thanks. Once again, drewblueeye, I'm not trying to hijack your thread, I'm just really desperate and need some hlep as well.

drewblueeye

WEVO,
Has this problem just started? or has it always been this way since you installed the BOV? Have you tried a different spring? I dont know about your BOV but mine came with 4 different ones... yellow, green, blue and red. the yellow is the weakest and that is what i run. Mine does a three spurt too IF i am letting off the gas really slow, but i mean really slow. BUT See my flutter problem that i am having at low boost happens with any spring that i have in.

lexat20

iTrader: (24)

check my previous post. I had this exact same problem with my forge

machron1

iTrader: (1)

Hey drewblueeye did you try out what I posted above? I'm about 99% sure it will fix your problem and then you can run whatever boost you want.

drewblueeye

yeah i had a nipple installed on my lower intercooler pipe and guess what! the flutter is gone. weird... but i called Forge Motorsport and they told me the same thing you did Machron1. All i got to say is thanks for your help Machron1, i appreciate people that answer questions and help when they can.

machron1

iTrader: (1)

No problem, glad I could help.

justchil

iTrader: (44)

Where did you get the nipple at? I haven't found a small enough one for 4mm vac lines...

occultworks

iTrader: (6)

Glad you got it fixed. Maybe this will help more people in the future with the same problem. It seems like it might be pretty common.

drewblueeye

i took the BR lower intercooler pipe and the factory lower intercooler pipe into a welding shop had them cut off the nipple from the factory pipe and weld it on the BR pipe in the same place, it cost me $10.00. but if you are a real DIY kind of guy, i guess you could go to a BIG hardware store like Menards or lowes and go to the plumbing section and try and find a smaller nipple and some rubber washers and drill the hole yourself. I wouldnt trust it not to leak that is why i had mine welded.

20psiMR

iTrader: (6)

Good ole quality buscher products!

machron1

iTrader: (1)

Yeah I don't know why they wouldn't just put a nipple there...and I don't know why they don't put flanges on their exhaust systems...that's why I don't go with their products, they seem sort of under-engineered to me. Like why do everyone else's UIC pipes clear the stock battery, and everyone else's downpipes clear the stock cross braces? Their parts work and they are affordable, but they just don't seem to have the fit & finish I've come to expect from mass-produced aftermarket parts from other companies.

justchil

iTrader: (44)

Just for the record their exhaust do have flanges now... you can even get the quick release vband type clamps Granted their stuff isn't the best looking stuff on the market.. but it's light.. performs and won't cost you an arm/leg.

machron1

iTrader: (1)

Good thing about the flanges, without them there is too much fiddling...