Well it is amazing what you can learn about a car on accident.
So i did a pressure test... NO leaks!!! Took out the car still fluttered.
Went out bought new clamps.... NO leaks!!!! Took out the car still fluttered.
Changed hoses.....NO leaks!!!! Took out the car still fluttered.
Double zip tied hoses.... NO leaks!!! Took out the car still fluttered.
....and then accidentally turned my MBC knob the wrong way, so i had to start over from the lowest setting which is 16psi. Took out the car at 16psi... NO FLUTTER????!!!!
Turned the knob a little at a time got it to 19 psi took the car out and still NO FLUTTER????!!!!!
Then brought it back turned the knob again got it to 20psi took out the car and it had a LITTLE FLUTTER!!!
The higher I turned the boost past 19psi the worse the flutter got. So my conclusion... Keep it at 19psi.

And anyone that writes in and says “well I knew that". Well then why didn’t you say anything??? BUT I am writing this to let everyone know that is what fixed my flutter. Make sure you are at 19psi and no higher.

 

i would think the flutter would have more to do with wga needing adjustment or your bov/dv

 

If you get the flutter at low boost, I don't think it would matter what your max boost is at. I think it has more to do with how you set up your DV.

 

This may be a stupid question, but everyone is aways talking about "flutter" but how do you know when the car is doing it? It always seems like a bad thing when people talk about it. I mean is it just considrered when the BOV vents, or is it something different. Does it make a distinct noise or make the car jerk or whats exactly going on here? Thanks.

 

I wouldnt take that as a fix. If I wanted to run 22 psi I would find a way to do it, not just lower the boost.

 

First to answer Dan628, trust me you would know if your system had a flutter...LOL....you would know. it would sound like your BOV is opening and closing really fast, about 6 times in 3 seconds, letting only 3 to 5 psi out at a time, but your turbo would still be building boost so your boost would jump up and down fast and your car would jerk. then all off a sudden, even though your foot is still on the gas pedal the BOV would release all your boost, even though your still driving and the car would jerk from a sudden lack of power. SO in a nut shell, you would know if you had a flutter.

OK and to respond to the people that said it isnt a fix. well maybe it isnt, maybe it is just a way to stop it, and yes i cant turn up my boost, so if i want to run 20 to 24psi then i cant...BUT until i know what is causing this flutter when i turn my boost up to 20psi or higher then this is a temperary fix. all i know is that i pressure tested the system and had it hold at 20psi with my air compressor in my garage and i didnt hear or feel any leaks. the only possible leak that i could still have is the the lower intercooler pipe that connects to the Turbo. that is if it is leaking between where the gasket is (picture 1). Also I have included a second picture explaining how i pressure tested my intercooler system (pcture 2). And I included a picture of what my pressure checker looks like (picture 3), it is a $0.79 PVC pipe end that I drilled a hole in and put a tire valve stem in the end of it....HEY it works. Then I just use my compressor and put 15psi to 20 psi in the system and listen and feel for leaks.

Feel free to include your ideas or comments on what might also be the fluttering problem or anything else you would like to add

 

Which BOV/DV do you have? I replaced one that I had where you put different springs in it. I put softer spring=no flutter but dosn't hold enough. If I put Hard spring in it held bosst but I had flutter. I have Forge now. When Iturn it up to high I get part throttle flutter.

Let me ask you this. Do you only get flutter when you let off the gas at certain RPMs? Does it happen when you let off quickly or only when you slowly let off?

 

I have a forge BOV from Buschur Racing. I have tried hundreds of combinations with the springs and spacers, from the weakest (yellow) to the strongest (red) with two spacers, and it flutters the same everytime.

 

OH and as far as the flutter goes... it doesnt happen when i let off the gas it is when i slowly push on the gas and slowly build boost. see at WOT it works fine and when i let off it works fine, BUT it is when i am slowly GIVING it gas (slowly pushing on the accelerator) that it flutters. see that is what i think people dont understand, it doesnt happen when i let off the throttle or when i push in on the clutch. it happens when i am driving and Slowly give it boost, like when it goes from 10psi to 20psi in 2 to 3 seconds.

 

i have the forge RS bov... I haven't found the exact least fluttering/boost holding sweet spot yet

 

It's odviously your BOV an/or WGA. Just buy Forge pieces to replace both and your problem is fixed with still getting the power you're tuned for.

There is no reason for a temp fix in this situation, we know the two main things that cause flutter like that, just address the problem.

 

i dont get it, maybe i am just a little slow. can you explain to me how it is my waste gate or BOV, if it DOESN"T flutter with the factory lower intercooler pipe with the nipple on the pipe, BUT it DOES flutter with the Buschur Racing Lower intercooler pipe without the nipple on it so i have to 'T' Splice into the line between the BOV and the intake manifold?

It just doesnt seem like it would be a BOV or wastegate problem just by changing lower intercooler pipes. but like i said in a couple other rooms i have never worked on turbo or supercharged cars. i am not saying you are wrong i just dont understand.

 

this is not flutter... this is your bov blowing open. flutter is when you let off the gas and your bov does the chug chug chug or psh pshpsh psh psh thing.

 

this is because the forge unit relys heavily on the pnumatic assist of the top nipple. you have to go wot if you want it to hold. otherwise you're really outta luck.

 

Howdy all,

I also have rapid "flutter" like sound at top gear freeway speeds. Sounds like air venting real fast. My boost guage does a crazy dance over a 10 psi range. It seems to happen mostly when I am tring to accelerate at 3/4 rate. I think it stops doing it if I really floor the throttle all the way. I have a GT3040 w/Forge Boost Controller and a 1G diverter valve. I have ordered a Forge RS to replace the 1G valve. Do any of you have experience adjusting the Forge RS? Will this solve my problem? Please let me know... Thanks in advance.