FLUTTER sound as BOV

[ocean]

Whether not running a BOV damages your turbos is questionable. Nispro have run cars without them and reckon it does no damage - the car is also faster, given that you can change gears quick enough..

-Patrick

[Mr GTS4]

mine made the noise ALOT more after i installed my front mount. i also have a APEXi dual chamber BOV and didn't adjust it for the first run after that and it sounded really good but i wouldn't leave it like that.. you'll kill the turbo.

you think about it, the turbo is spinning one way then when you get off the gas all this air has to go somewhere. that place is back through the turbo which is spinning the other way.. thats when you hear the chop noise.

[Baz]

Yeah in the case where a BOV isnt operating sufficiently the air bounces off the throttle plate when it snaps shut and the only way to release its pressure is back through the turbo.

[foznice]

okay, so if the BOV is blocked up you get a whole lot of copressor surge, but what actually causes the 'fluttering' sound and why do you need an after market POD filter?

[CONAN]

good question foznice, i wanna know now too!

[R32_GODZILLA]

Peformance wise, wouldnt it be better to have a complete plumback system wired to flow back just after the airpod? By doing that wouldn't it reduce turbo lag?

Thats an interesting question. Although, it does sound logical......

Has a plumback system been designed this way? Or anybody using this setup?

Steve.

[RedRocket]

Yes thats right.

My car came with the factory valves blocked and it was SHIT.

It fluttered and was laggy.

So I had the plumback reinstated and now it works BETTA.

I can't believe that you care about

some poxy sound resulting from a flawed setup, rather than

having you car working properly.

Why don't you make a recording of it and just play it on your stereo?

Or is it for everyone else to hear.

[bkn_computers]

as some were asking before, you need an aftermarket air filter to HEAR the flutter because it has less restriction. you may even have the same flutter with the stock air box, but you just cant hear it. but the sound does come from compressor surge.

r33zilla : you will NOT get flutter with a HKS ssqv, believe me i've been there done that. the ssqv was designed to elimnate EVERY possible effect of compressor surge and flutter, its just the way its engineered and designed. you will only achieve the faintest flutter, which you will barely even hear.

hope that helps

[pentae]

Bloody posers.

[GR33DY]

if u have a stock bov, and an air filter with a large surface area such as an HKS or TRUST one u will get little flutter.. But if u got an after market BOV running stock boost and u got an air filter it will flutter pretty loud... The reason y u dont need to remove ur aftermarket BOV is cause the spring inside it is really tight and only releases when ur on high boost (8-12psi or whatever).. The Stock BOV has a very soft spring... Once u get an airfilter ur car should flutter at low revs, but once u get above 5000 rpm, it will go tshhhhhh the normal sound which is normal.. I had a stock R33 and did that and got alot of flutter.. When i put my front mount on it was even louder, and when i changed the piping to stainless steel igot even louder lol!!! It is pretty mad, but be careful with what air filter u buy cause some dont filter as good as others.. But if u just want the sound, defenitely buy a HKS mushroom or a TRUST Arinx one for abt 100 bucks second hand they always for sale.. And changing the stock air filter to the pod is very simple, shouldnt take more than 40 minutes if u got the right tools..

hope that helped..

Rob

[ATTN]

bkn_computers: im aware that i dont get the flutter sound on my BOV only at low boost i can hear it but not loud but thanks anyways.

in regards to air filters whats good? i currently got K&N air filter, whats better eg. HKS

[Dim1]

maby the air box muffles the sound to much?

[aKTiVE]

ahaha this question plagues every forum.

To enhance your 'Flutter'

you will need a AfterMarket POD Filter.

an AfterMarket Intercooler will help amplify the sound

Different sized turbos will also depend on how loud, how deep, how high pitched

The big thing, is having steel piping from the turbo to the pod filter. Usually its plastic from the factory and people rarely change it as its not really necessary... but changing this pipe to a steel one, will help amplify the sound.

People will argue to death that it kills turbos and whatever, and its more laggy all kinds of stuff... and really, its horses for courses - whatever you prefer.

I had a bov on my vl turbo, the spring in it died and the bov was useless (could not hold more than 7psi boost and would open up sounding like an external wastegate but losing all horsepower), that sucked... it was a TurboSmart Type III. after that i just took it off and had the hole welded up.

I had a bov on my R32, and it wasnt placed properly (it was not hidden)... stuck out like dogs balls, and as soon as a cop pops your bonnet, they think its christmas when they see it, because they dont know fcuk all about cars, but they know what bovs look like and they know it shouldnt be there...

I remember i told a cop it was standard, argued the point and got away with it. But i removed it anyway.

[someonestolecc]

Bloody posers.

It's full sick.

I have a s15 stock re-circ. If take your foot off the accell quick enough when on full boost you still hear crazy woosh for some reason (I thought that wasn't meant to happen with a re-circ)... this thread makes me worry now maybe it's not up to the job but I'm only running .8 bar or so. :confused:

I still don't understand why people want these noises - just get a bigger turbo and make noise with the wastegate

[GR33DY]

hey mate that woosh sound is normal... i get it too... i only got after market pod and when i quickly take my foot off the accel. it goes wooshh lol its normal man dont worry abt it

[JCMarshall_Law]

This thread is gay.

The "flutter" sound (not to be confused with the sound from a sequetial BOV) is compressor surge, it happens when the compressor is operating severly out of its efficiency range, it is not a good thing.

So when I hear a car drive past fluttering between gears, I dont think "fully sick man", I think "that car is set up like shit, and that tool thinks it is great"

If you want it to be louder,

1)block up the BOV (causes the compressor to operate at essentially zero flow when changing gears) ie; way out of its efficiency range,

2) get a pod filter - stock box is designed to muffle the sound,

3) FMIC - larger volume of compressed air for the compressor to work against (at zero flow) during gear changes.

All that should reault in a longer louder flutter to tell people your car is fu(ked.

Sorry if I have offended anyone.

[aKTiVE]

its ok, you must have sand in your vagina.

[pentae]

I guess theres a few of us who have mechanical sympathy and refuse to try our best to break a perfectly decent engine for the sake of being the coolest kid at the maccas car park.

Weird.

[aKTiVE]

Its personal preference really.

[JCMarshall_Law]

Go for it man, its your car. Just telling you whats happening.