Are you speaking of the Forge RS Diverter? Does this mean that the "flutter" can't be adjusted away via the knob and the "flutter" situation at part throttle is normal/unavoidable??

 

You never said anything about LICP before, so now i have no idea.

 

I have read many a time about the flutter on cars equipped with the Forge BOV. The deal is it is a single chamber design, versus stock which is a 3 chamber. This allows the unit to hold more boost than stock. I think we will all experience some level of flutter when giving PARTIAL throttle. This can be adjusted to happen minimal, but it will take some doing on the users part to find the sweet spot. I actually had my BOV turned down to low setting with the spring pressure, when I happened to turn it up for an autox and then drove home, I experienced minimal boost flutter. So I adjusted high and have really improved the flutter situation, because I have to try and make it happen, kind of less sensistive to my throttle input. BTW, I have Forge BOV, MBC and WGA, all of which are adjustable.

 

I would also check to make sure there aren't any kinks or obstructions in your vacuum line going to the BOV. Also make sure it's as short as possible.

 

try a 1G BOV.. im sure that will solve the problem!!

 

99% of the time "flutter" (the effect of compresser surge or compressor stall) is because of your BOV. I'm not certain why most aftermarket springs are so heavy, since the pressure on the top of the diaphram should equalize the pressure inside the system for the most part when the butterfly is closed. I have the Greddy type RS and took the biggest spring out and have almost no tension from the screw and I rarely get flutter. With both springs in I got a ton.

 

this is precisely the problem they're describing. at partial accel (not wot) the pressure on top of the diaphram is not enought to hold down those weakly sprung valves for those running "street" boost.

what needs to be done is a DUAL pnumatic assist. this would assist when venting and assist when holding. only the mitsu style valves do this. search the end all bov thread for more info.

 

Wow everyone has different answers to the problme, and this weekend i tried them all. First i thought, lets try a different BOV so i tried the factory one... still flutters!!! so then i changed the hoses for the 5th time... STILL FLUTTERS!!!! so then i thought that i would try ANOTHER size of 'T' ,which i have already tried 3 different sizes, and guess what... STILL FLUTTERS!!!! the higher the boost the worse the flutter. when i first turned my boost down on my Buschur Racing MBC to 19psi, i thought the problem was gone, but it wasnt, it was just not as bad. and I know for a fact that i have no leaks between the Buschur Racing lower intercooler pipe that connects to the intercooler and the intake manifold. so the only place that i could have leaks is either in the lower intercooler pipe that connects to the turbo or between the lowerintercooler pipe and the turbo where that gasket is. And just a FYI, i have tried to use the gasket that was included with the Buschur Racing lower intercooler pipe, then i tried to use the factory one, then i tried to use both together.... STILL FLUTTERS!!!. OHH and as far as my clamps to the intercooler pipes. I took all the facotry ones off just because i wanted to know for sure that there was no leak and replaced them with ones that i bought for $7.00 EACH, from the Tractor/deisel supply store...(picture included) now these are some heavy duty clamps and the guy sells the T-bolt clamps too and he said to go with these if i wanted to be positive that it wouldnt leak.
All I know is I am about to the point to drive the 12 hours to Ohio and have Buschur Racing take a look at my car, so People stop thinking I am crazy. There is a flutter and it is driving me crazy. I would put the factory Lower intercooler pipe back on jsut so the flutter isnt there but it doesnt fit 100% correctly on the Buschur Racing Race front mout intercooler... I just want my baby running right

 

drewblueeye, What about modifying your driving style. I know that some may say that is crazy and why should you have to do that. The fact is maybe you have to accept that partial throttle in these cars does not work. Either your sort on it, on it or totally letting off. I try and drive like that and that really helped the problem. This is only a problem for me on the highway or in heavy traffic where I have to change throttle input all of a sudden.

 

the flutter is not coming from your BOV but from your intake. The flutter noise is air being push out of your intake from the turbo. Thats why when u left of the throttle and dont get on gas agian it will fluttter(turbo is releasing air out) but when you get back on the gas right away it goes away( the turbo is now sucking air in).

I have the same problem. Still dont have a solution. Im told AEM EMS with MAS air delete.

 

I think your flutter is coming from your dv. You have the old style piston in it that needs to be replaced. I had the same problem. Call Mike at forge he will help you.

 

well i went out and video taped what happens with my BOV, this is slowly giving it boost. at no time am i letting off the throttle, at no time am i pushing on the brake, and at no time am i pushing in on the clutch while it is sputtering.
Here is the link to the site i uploaded the video too.

http://videos.streetfire.net/video/0...c4e7d25edc.htm

Any suggestions?

 

thats pretty bad...thats definitly your BOV. i would try to take off your BOV and cap the opening some how. if it goes away its the BOV,my car use to do that on a fifth gear heavy load.

 

i have drawn out two pictures showing the factory set up of an EVOLUTION 8 and the Buschur Racing setup of an EVOLUTION 8. I really hope there isnt any confusion. The first picture is the factory setup, the second picture is the buschur racing setup. also i will include the link to the video

http://videos.streetfire.net/video/...0c4e7d25edc.htm

Also this happens when slowly accelerating and slowly building boost. I am not letting off the gas, i am not braking and i am not pushing in on the clutch.
This does NOT happen when I am WOT (pedal to the floor) it holds boost fine if i am WOT (pedal to the floor).

Also the higher i set my boost the worse it gets. i keep it around 19 to 20 psi, but it still does it.

I really cant think of anything else to repeat. i think i covered everything. all i ask is one thing... if you have a question please be sure that i havent already answered it in this forum cuz i am getting a little frustrated, BUT I do want to say thank you for everyone's help and ideas. all ideas are welcome and i will answer any questions you have and am willing to do about anything ot fix this problem.

 

You know, I know this sounds strange but have you looked at your MBC? I have seen a case before similar to yours. Not as bad (only fluttered a little) but it looks like you are bouncing almost all the way down to the Wastgate holding pressure. Try a different MBC or removing it (if you still have the stock lines with the pills). I bet that could be your problem if it is not the BOV.