Vindiesel075

Hey guys i have a problem with turbo flutter and comp surges at low boost. When i shift at 6 psi(my max) its fine but anywhere below 4 psi i get ____ty flutter after my bov action.

Heres my current set up

Dezod Turbo kit
Turbonetics turbo charger
HKS BOV ver 1 (adapter pipe that is 2.5 in into 2.25 in charge pipes) It is located just before the throttle body and is at the softest adjustment
Tial Wastegate

My vac lines are 5/32 ID . I have one running from comp source on the turbo to the side port on the wastegate.

I have a vac block which is has my throttle body line running into it. Along with my bov, boost gauge (aem digital) and AEM FIC.

Current set up makes 22 in of vacuum at idle 24 to 26 at deaccel.

I used to have a greddy type rz that fluttered as well


any suggestions?

Heres what i am working on now....

Getting a 2.25 in adpater pipe and moving it closer to the intercooler



Any other suggestions will be appreciated

Thanks!


the pic is of the set up with my greddy

bigG2148

Get a new bov maybe a tial

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bigG2148

And u sure that's an real tial wastegate

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Vindiesel075

ya pretty sure

StreetSweeper

Idk what the wg has to do with this but anyway. How many port are there on ur bov? On my turbonetics raptor there's 2. If I only connect one source then I get flutter but by connecting both one to the compressor n one to my vacation block most of it goes away unless I bearly spool the turbo. Find the install instructions n see what they recommend

Vindiesel075

ya i know really but mine only has one vac port....

GUNNIST14

iTrader: (1)

Many have said the Greddy RS-RZ series leak quite frequently I need to to check mine.

But I think you need to raise the level of the HKS a bit and see if that clears up the flutter.

Fluttering is caused by negative pressure bouncing back off the throttle body and not be released properly by the (BOV) after boost is created.

Everything else sounds good so readjust the HKS to a firmer setting and let us know what the results are.

PeArLwHiTe07tC

iTrader: (2)

Synapse bov!! Get one.

ScionFred

iTrader: (1)

To get rid of compressor surge/flutter, shouldn't the BOV be set softer?

Syldrin

iTrader: (1)

Make sure your bov is hooked up to its own port in a vac block or a vac line and don't t in to it. If that doesn't work switch to the synaps.

Didn't read it all at first. The rs and rz will always flutter switch bov's

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Vindiesel075

i have an hks right now and it still does it and the bov is hooked up directly to its own port.

browniemxn

I have tried both the hks and the Synapse on my car. The Synapse totally gets rid of all that flutter. However, I'm in a different country and the synapse opens while crusing (85 MPH). I would opt for the Synapse diverter valve instead. I would also recommend recirculation for your setup. All that metered air is accounted for by the MAF and will leave a rich condition after shifts. I have also found if you do a Synapse setup you will need a "venting kit" if you don't recirculate. The Synapse will stay open until positive pressure is sensed then it will close to hold the boost. Having it setup this way also helps with idle and between shifts. HKS BOV will always flutter under certain boost conditions. The Synapse recirculation valve is my next purchase. I will be selling my Synapse BOV and my HKS to get that gem! This turbo flutter will eventually lead to the destruction of your turbo! Nip that in the bud pronto!

GUNNIST14

iTrader: (1)

In my case and what I have experienced when I changed my setup to a log style manifold from top mount the bov fluttered terribly when shifted at low rpm.

I have a RS and the adjustment screw became worn so i changed it and turned it too a firmer setting. No more flutter and more response and more affective release of pressure but I'm blo-tru so it might be a different scenario for Diesel since he recirculates.

Good info brownie the greddy's are a bit dated compared to the HKS OR SYNAPSE.

Vindiesel075

ya man idk the only thing i can think of is my turbo is a little to big for my application. It is the older dezod set up with the turbonetics i believe it is a 60 trim t3/t4? When i make the spring a little firmer it does seem to shut better but idk i guess ill adjust it as best i can....

ScionFred

iTrader: (1)

AFAIK BOVs don't flutter, the compressor wheel makes that sound when back-pressure is present due to the throttle closing and the BOV not opening fast enough or far enough. In theory the BOV spring preload should be lowered to reduce or eliminate that flutter sound. YMMV.

I have my BOV set about 1 psi above vacuum idle so it remains closed except when back-pressure forces it open. I get a lot of low rpm flutter but I don't think that 1 psi of back-pressure is enough to damage the turbo. At higher rpm the BOV vents much cleaner although it's recirculated and not the best BOV. It's a Greddy type S clone but it does the job okay for my low-psi setup.

I don't see how a manifold vacuum referenced only BOV can vent all the back pressure unless it's set so soft that it opens at or barely above idle vacuum. If set this way it will open whenever vacuum exceeds idle vacuum. Now if you add a boost only connection to the bottom chamber the BOV will open faster and further. I need to try this. Note that everything I've said is related to a typical 2 chamber diaphram style BOV like Greddy, etc. I don't know precisely how the HKS or Synapse work.

XPRTc

iTrader: (5)

If it's the BOV that's fluttering then I would imagine that it's just not seeing enough boost/vacuum for the valve to open completely so it opens/closes quickly to release what pressure build up there is. If it's not the BOV then it's compressor surge which is not good, but I've spoken to a rep at TiAL and he mentioned that surging at a couple psi won't harm the turbo although I don't think anyone would really want that.

I hooked up my TiAL directly to the intake manifold and left the pcv open to atmosphere. This way it is a direct and independent vacuum source.

Just from my experience...

Syldrin

iTrader: (1)

what version? V2 and V3 are known to have flutter.

PeArLwHiTe07tC

iTrader: (2)

hes runnin the v1 according to his 1st post.

GUNNIST14

iTrader: (1)

Touche' Fred you make valid points that I can't disagree with.

LOL what's AFAIK....

ScionFred

iTrader: (1)

Thank you. That's the theory as I understand it anyway.

AFAIK = as far as I know