BOV fluttering only in 4th and 5th gear.
 

I've read alot of the articles concerning the HKS SSQV fluttering problems, but I don't know if whats happening to my car is the same. 1st, 2nd, and 3rd gear boost just fine and BOV operates as it should however once I get to 4th I get serious fluttering at 10-12psi.

I was venting to open atmosphere so I switched it up to recirc thinking maybe that slight amount of vacuum from the recirc would help hold the valve closed but it was a long shot and didn't work.

I've also been running my boost low @ 23psi (BR 3065 turbo) from my normal 27~30 that I was running previously.

I'm hoping someone can come up with some theories or fixes as well as an explanation as to why this is happening so I can better understand the problem. Thanks in advance.

turbo surging? could be how u let off the gas in your car. try letting off of it fast and see if it flutters. most of the time its because people slowly let offf the gas after accelerating

The thing is its happening under acceleration, even 100% throtle. I cannot get it over 10-12 psi no matter what I do in those 2 gears.

are you on SD?

Sd?

I had the same problem with my SSQ. It wouldn't let me boost over 16psi though, and it would start fluttering.

Switched to a Tial 50mm with the White spring (9psi I believe) and haven't had a problem yet. Holding 25psi rock steady without any flutter at all under partial throttle or when going into boost. {thumbup}

Was yours happening in every gear or only specific ones? I Just can't figure out why it's only doing this in 4th and 5th gear. I don't really want to go replace my BOV or gate if I have some other underlying issue.

Started out just in 4th and 5th gear when you would try to roll into the throttle.

Then I'm not sure why, but it got to where it wouldn't let me hit full boost when trying to make WOT passes in any gear. It would just start fluttering and falling on its face at 16psi (1st through 5th gear) didn't really matter what speed I would run. As soon as I tried to go WOT it would flutter at 16psi.

Dunno if these things are notorius for the spring or diaphragm going weak or what? :confused:

I had SSQV and it did the same thing. I was able to get 20 to 22psi in 1st thru 3rd and 4th and 5th would only go to about 15psi. I found that my timing was off, major boost leak and i needed new spark plugs! The problem went away after that!

Good lord, lol. You were lucky to get running that good with all that stuff wrong. :lol:

speed density
you said that you were vta

do a boost leak and let us know what happened


GL

compressor surge.. dont floor the car at low loads in 4th or 5th gear, its very very damaging to the turbo and can actually blow your motor if you're lucky enough. whats happening is the turbos trying to flow so much airflow into the motor, the motor chokes on it and it comes back down and trys to s pin turbo the opposite way.. your bov will go off and it will surge.. not good at all!


get your rpm's to about 5-5500rpm and floor it in 4th and watch the problem be gone :)

Sweet guys, thanks for all of this. I really needed to hear that other people were having the same issue, I couldn't find any other posts that mentioned the behavior being 'gear' specific. I replace my plugs constantly anyways so I don't think that's the issue, I never though the WG would effect the BOV like that in specific gears, but definatly somthing I can look at now. and I need to do a leak down test on the system anyways.

If there's any other ideas out there coming and I'll keep everyone posted as I work on this. I don't really have the $$$ to buy a new WG at the moment I'll have to do some selling. Thanks again.

Well hell I can try that on the way home from work. I'll give it a shot, makes sense I guess. Thanks

Synchronic time. 28 psi all day every day 4th 5th 6th