I currently run a forge VTA BOV, it seems ok, but when i floor it in 5th WOT with MBC set to 20psi, seems make a loud fluttering noise which is the BOV, if i change spring or add shims, it flutters at reg driving. I cant deal with it, i am now looking into:

Greddy type S BOV Single spring modded (seems to be 1 of the best BOVs for the

Evo)


Turbosmart Dual port BOV (i love bov sounds and still good drivability)


Forge Recirculating BOV (it recirculates, but still has that spring shim combo so dont know if i wanna deal with that)

Basically what im looking for is something holds boost at WOT in any gear ESP 5th, rough idle is ok as long as it doesnt stall out, quick and accurate response between shifts.

 

Quick and accurate, I would say you need to stick with a recirculating setup. I think every bov has its issues. It is proving to be very difficult in finding one that will not flutter during everyday driving (esp highway) and still hold above 20-21 psi. Good luck

 

try the MR DV

 

i've seen a bunch of different BOV's for the evo and almost all of them flutter. I spoke with the guys at AMS tuning about it, they told me when it comes down to it, it's just the way the evo works. I have the forge VTA and i have adjusted the spring so it lets boost off slower and more smoothly. when it flutters, it's called compressor surge which isnt great for your turbo. Usually it's caused buy a spring thats too stiff for the amount of boost you have. I have the second to softest spring in the Forge. So minimizing the flutter is what you want. I think the forge is the most versitile valve where as you have 4 springs and several shims to choose from. when it flutters, it can also cause stalling so changing the spring to what you want is crucial. hope this helps!

 

[QUOTE=Vroompsh]when it flutters, it's called compressor surge which isnt great for your turbo. QUOTE]

I was told by forge, the flutter is not exactly compresor surge, just the valve closing prematurely or irradically. Really only affecting driving comfort, and really nothing to seriously worry about.

 

Why not just get the MR DV? Is noise really worth all of that trouble

Edit: Nevermind, didn't notice you had an intake. I dont' think the MR BOV works with intakes.

 

I've got the forge recirc, I left the springs and whatnot alone and just put it in. Holds boost perfect and doesn't flutter at all, perfect.

 

does running VTA make the car lose boost inbetween shifts is my main concern. My car feels very weak inbetween shifts.

 

bump? PS: do most prefer the type S single spring modded recirculated or the MR DV?

 

greddy with single spring is great, its the third bov ive tried and it runs better than perfect

 

I put in an order for an APS bov. It is a dual vent...it recircs normally, but under high boost it ports VTA and recircs...I talked to several people who have this BOV and all of them say it works great!

 

is Greddy BOV good??

 

great, it holds boost, doesnt flutter "turbo surge", and sounds great

 

to tell u the truth i've had the type s as my first aftermarket bov, but i've been thru so many bov's (7 and counting), i forgot how the greddy performed, what i do remember is, there was NEVER a time it fluttered at low or high boost, WOT or partial throttle and single spring modded type S idles PERFECT.

 

Well whatever it is, it's not a good thing whether it effects your driving comfort, or your turbo. I say no to flutter! lol And compressor surge isn't going to kill your turbo, its just not great for it. Kinda like having an oil catch can...you can do without it but it helps the long-term life of your turbo. My stock DV fluttered sometimes on the highway, so as i said before it also has to do with the evo's setup.