I have searched and searched and can't find a solution to my problem. I've seen many threads about it....but no solution, except to switch bovs or go back to stock evo 9 bov. Anyways, I recently switched from an hks vta bov to a turboxs rfl vta. I'm running 24 psi of boost, but if i only give it partial throttle and boost around 18-20 psi i hear a horrible flutter/leaking noise and my boost gauge goes crazy.

If i stay in vaccuum its fine, and its also fine when at WOT. I've tried various springs and washers...but to no avail. For daily driving this is unacceptable. It sounds fine when i let off the gas quickly....it gives me a nice wooooosh sound.

Only at partial throttle while im in a load does it make this horrible flutter/leaking noise...but when i let off the gas, it blows off normally.
Anyone else have this problem or have suggestions?

 

Ok....I just put the adapter on to recirculate it and its still doing the same thing. What is up with this bov? No one else has experienced this?

 

Yes I ditched that thing faster than a hooker with herpes.

Using a type s now.

The rfl has poor part throttle manners. Heavy piston slow response soft spring. They make it loud but drive poopie. You can get a hardware store spring to make it stiffer too

 

I have the same part throttle flutter with mine a and its on the forge bov.

 

They're the same design afaik. A valve area equal to the piston area. It's simple and works on strip cars but pressure differential between valve and piston are not handled well. The best on the market do this well with unequal areas between the valve and piston.

The synapse , greddy, oem, samco, + more have one thing in common. They play with balance over the pressures for desired effects. Part throttle leaking is a good thing but surging is not. It should be controlled easily with your right foot.

 

are you actually boosting when it flutters? i have yet to find a valve that doesnt flutter but if you are in boost i could see an issue... if i accel part throttle just around 0 it will flutter on mine but its a very rare occurrence...

 

Mine fluttered violently like the op describes . Lifting throttle from a good amount of part throttle boost and chchhcchxhxhxhxchxhxhxhxhxhx nearly as long as I hold my foot there it would do it and my boost gauge would go crazy.

My current set up flutters zero. Part throttle is amazing and very small throttle changes are perceptible via valve noise

 

it makes the flutter noise during boost/in a load. if i floor it its fine. but if i keep my foot in the gas 50% it sounds like it leaks and makes a horrible flutter noise. but when i let off the gas it blows off normally.

 

like for instance.....if i only wanted to boost around 15 psi (mbc is set at 24) by just giving it partial throttle it flutters and stutters and my boost gauge goes nuts untill i floor it or let off the gas.

 

Right, it doesn't work well with your setup. Try a different spring both softer and harder. A few dollars at the hardware store.

 

Leaking at part throttle is a good thing. The pressure pre tb is higher than post therefore differential pressure is vented.. Maybe you need a softer spring?

I played with mine a few different times and the softer vented nice at part throttle but I was unsure of boost holding with equal piston and valve sizes with soft spring like that .