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FLUTTER sound as BOV

ATTN

By ATTN,
in Engines & Forced Induction

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2BNVS Veteran

2BNVS

Posted
Posted

when i got my cooler fitted with my pod, my stock bov was fluttering, now i have the GFB Hybrid bov and its great, no problems with stalling due to part atmo/part plumback, just as loud as supersonic bov, and it flutters when i make about 3psi max then its just like normal over that so it shouldnt cause much damage on the turbo...

ben...

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Skyrine-Dave Mentor

Skyrine-Dave

Posted
Posted
Anything under  6psi will not harm your turbo....

A HR31 does not even have a BOV as standard (i used to own a couple)

If you plan on running 7+ psi then use the above info...

Col... HR31 and VLt's didnt have BOVs... but then again they are 80's technoology cars and these days almost all turbo cars have factory fitted bovs

  • 2 weeks later...
  • 4 weeks later...
THE_REAL_SLYR33 Explorer

THE_REAL_SLYR33

Posted
Posted

that noise you all want is damaging your turbo i know it sounds good i have it myself and yes by blocking off the blow of valve you will get this noise thats how i get it also using a pod filter the noise is caused when the throttle body is shut the air in the pipes has nowhere else to go but back normally out the blow off valve but since its been blocked it can only go out through the front housing of the turbo wich causes the turbo to try turning back the other way producing alot of stress on the shaft it bounces back and forth of between the throttle body and front housing till all the air has escapped so NOT GOOD but sounds great i have yet to blow up a turbo but mine is aftermarket just thought you might like to know a few things i own my own shop and often mod cars and people ask for this sound and i wont do it for obvious reasons WHEN IT BLOWS UP I PAY

  • 2 weeks later...
  • 4 months later...
kpgc10 Newbie

kpgc10

Posted
Posted

most of the drifters here in okinawa have this sound....its called backpressure. my car has it, what i did was take the hr31 piping and put this where the blowoff piping was, then hooked up my boost gauge to the vacuum line and plugged the bigger hose with a bottle cap. it wont damage your turbine if you have the stock turbine and intercooler...it should be fine

Nik Black Newbie

Nik Black

Posted
Posted

BAD BAD BAD. Don't do it. I blew a turbo from not having a BOV fitted running only 11psi. Get a steel shaft turbo if you want that noise.

The turbo is flowing a LOT of air under boost and as soon as you release throttle the throttbe body closes while the turbo is still spinning causing it to reach very high boost levels between the turbo and throttle body.

If you want to see for yourself how bad it is just hook your boost gauge up before the throttle body and watch the needle go off the scale when you take your foot off the gas.

RyanN Rising Star

RyanN

Posted
Posted (edited)
when i got my cooler fitted with my pod, my stock bov was fluttering, now i have the GFB Hybrid bov and its great, no problems with stalling due to part atmo/part plumback, just as loud as supersonic bov, and it flutters when i make about 3psi max then its just like normal over that so it shouldnt cause much damage on the turbo...

ben...

Nengun sell a HKS product that prevents atmosphere style BOV from stalling the car. However i had no problems with a GFB mach 1 atmospheric type on my r34.

http://www.nengun.com/catalogue/product/578

Edited by RyanN
Rolls Grand Master

Rolls

Posted
Posted

It is not proven that not running a bov will harm the turbo at all even at high PSI.

It can even cause the car the be less responsive as you have to repressurize all the tubing when you get back on the throttle. (More noticeble with a frontmount)

  • 3 months later...
Suspct_32 Apprentice

Suspct_32

Posted
Posted

The fluttering effect that ppl get is compressor surge which is the air building up when the butterfly flap is closed (not accellerating) and pushing back to the turbo bouncing the returning air off the fins.

I wouldnt recommend it as if you are running a ceramic turbo this stuter effect that is being forced on the turbo can break off the ceramic blades, which will result in one screwed up turbo.... Sounds cool, but messes sum turbos up bad..

  • 2 months later...
funkymonkey Grand Master

funkymonkey

Posted
Posted

gheyest thread ever. omg fullsick hektik I get to make a flutter noise.

Backpressure is harmful especially if you're running non standard boost levels. However, its all fun and games on stock systems. Hell my 57 year old dad's Cefiro came with factory flutter because they have no BOV in stock form so the backpressure makes the RB20DET turbo "flutter".

In any case, how in the hell did this become a DIY thread. Moved.

RANDY Veteran

RANDY

Posted
Posted

lol! How indeed! I guess it does tell you how to do it... blocking off your BOV.

Sounds like we need a new section for "decreasing performance". It can contain large chrome wheels, blocking off BOV's, and buying Chinese eBay manifolds! =-p

TTT Grand Master

TTT

Posted
Posted

I guess the people with knowledge on this decided that telling the same thing over and over and over and over and over and possibly much more over again, is too much and don't bother when new posts liek this come up.

here is a VERY good explanation of it all.

sure it's on NS.com but the author is a very knowledgeable person..

http://www.nissansilvia.com/forums/index.p...=28060&hl=stock

read it and then shut the hell up about flutter and what your theory on it all is.

if a mod wants to make that link above a sticky about fluttering, then that would be good.

then if the mods would BAN FOR LIFE any person that mentions flutter again, that will also be good

psybic Proficient

psybic

Posted
Posted
I guess the people with knowledge on this decided that telling the same thing over and over and over and over and over and possibly much more over again, is too much and don't bother when new posts liek this come up.

here is a VERY good explanation of it all.

sure it's on NS.com but the author is a very knowledgeable person..

http://www.nissansilvia.com/forums/index.p...=28060&hl=stock

read it and then shut the hell up about flutter and what your theory on it all is.

if a mod wants to make that link above a sticky about fluttering, then that would be good.

then if the mods would BAN FOR LIFE any person that mentions flutter again, that will also be good

F#CKEN AYE!!! I don't even bother explaining it anymore when people ask about why my car makes certain noises. Just pat them on the head and say "Just keep doing your thing guy"

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