Stock Bov, But Still Hearing Turbo Flutter

[Trav33]

I'm still fairly new to Skylines and turbos,... but have had the chance to buy a slidingperformance high-flow and install it.

I've been worried that i have been hearing "turbo flutter", which happens when your blow off valve is blocked off? But after reading this thread (see below), i'm thinking the noise might just be more evident because i have a high flow and pod filter.

http://www.skylinesaustralia.com/forums/in...howtopic=141983

These are photos from my engine bay, i dont know much about bov's, but it looks like i have the stock one?

Is there anyway to tell if my bov is not opening properly, and i am getting turbo flutter/compressor surge - or if the noise is occuring when the bov opens and recirculated air hits the turbo blades?

Hope i havent said anything too stupid above - correct me if im wrong!

[J34]

Yep thats a stock bov.

[mad082]

how much of a flutter do you get? is it only 1 or 2 then it dumps normally? the reason i ask is that it looks like the bov has been squashed slightly (to raise the spring tension). if it does it once or twice then dumps then i'd say that is what it is.

the other thing you can do is remove the bit of rubber hose (the plumback bit) and make sure there isn't a plug of some sort in there.

[Trav33]

I get a fair bit of flutter, under boost, its like 5 or 6 flutters - hard to count! i'll try and record the sound next drive. When i replaced the turbo, i didnt notice any blockage in the recirc pipe from the bov to the turbo inlet.

[NICKS33]

doesnt look squashd 2 me......

[Thunderbolt]

I wouldn't worry too much. Flutter won't harm your turbo. It's just the sound of air being chopped up. If you watch the air filter when it does this, you will probably see it vibrate a little. Takes a lot more effort to destroy turbo blades etc.

[MATTYBE]

Put the stanard airbox and airfilter back in mate, you wont here it anymore.

[Freddy Kruger]

i have the stock bov on mine and i have zero flutter. i think your bov might be shagged and its not opening properly? take it off and grease it up maybe?

[justin911]

ive got the stock airbox/bov and a hks 2535 and i also get a soft flutter noise when im under like 5psi or so.. anything over and the bov seems to function normaly. didnt happen at all with the stock turbo

Put the stanard airbox and airfilter back in mate, you wont here it anymore.

[SilverECR33]

Its because of the Hiflow, theres alot more pressure now then before with stock turbo, and the flutter is normal. My mates R33 did same thing after he got his hiflow turbo put on,

VL turbos, didndt have blow off valves or intercoolers stock, and they fluttered all their lifes, and still drive around fine. so i dont think the flutter will hurt your turbo or engine very much at all.

its fine. if u wanna stop the flutter, u just need a larger bov. But my mates left his stock BOV on, and its fine. no problems as yet, after 2 years of driving.

[Freddy Kruger]

Its because of the Hiflow, theres alot more pressure now then before with stock turbo, and the flutter is normal. My mates R33 did same thing after he got his hiflow turbo put on,

hmmm i dont know much but wouldnt be more the bov than the turbo causing the flutter? perhaps low psi (lowest you can go on an r33 i think it 5-6psi) is causing the flutter as its not getting the bov to open? im running 11psi in my r33 and even when i was running min boost the bov worked normally.

take it off grease it up and see what happens... lol that sounds dirty...

[Sub_woolfer]

Put the stanard airbox and airfilter back in mate, you wont here it anymore.

That's a very good idea. Aftermarket intakes ususally do that to the engine. You'll hear the flutter with a bigger aftermarket intake on the car. Try removing it and putting the standard box back on and see if theres a difference in noise or perfomance. Performance depends on how big the bracket you installed the intake on it is, if its small, you'll be restriciting the available air and you'll find the cars running lean.

If it's all good in that department, then its it's normal or hear flutter when the throtle body closes and you have a stock BOV and an aftermarket intake on.