Jump to content
SAU Community

FLUTTER sound as BOV

ATTN

By ATTN,
in Engines & Forced Induction

 Share

Recommended Posts

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...

  • Replies 41
  • Created
  • Last Reply

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Popular Days

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"

Guest
This topic is now closed to further replies.
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Erelyes
      Ceramic turbine damage to engine - what did yours do?

      By Erelyes · Posted

      Ha, well, it's been.... a bit of a journey. Things have taken much longer than I'd hoped. I'll probably put up a thread at some stage. Hopefully soon. The car's not done any kms since my update in June though, put it that way.
    • Dose Pipe Sutututu
      M35 Aftermarket Fuel Pump

      By Dose Pipe Sutututu · Posted

      Here's the chart for fuel pressure vs. current draw, assuming your base fuel pressure is 3 bar and you run like 0.5bar boost on WOT, you should only momentarily hit 9amps here and there. (Ignore my prev post, I cannot read a chart these days it seems)
    • GTSBoy
      RB25 Drama's

      By GTSBoy · Posted

      Those comp test results are not hideous. Whether they are accurate or not (ie, when that comp tester says 140 psi, is the real pressure120, 140 or 160?) is unknown to us. The state of the battery used to crank it over is unknown, etc etc. Many people around here would say that the absolute values and the spread are perfectly fine to just add boost and keep going. I personally would be happier with a narrower spread than that, but even the diff between 125 and 145 is not terrible. That one cylinder at 125 though, has probably copped some damage relative to the others. You should inspect the valves seeing as you've got it open. Do you know how to measure installed ring gaps? That, and an inspection of the rings themselves, is how you will determine whether they need to be replaced. If you're not good to do these things, take the block and the pistons and rings to a shop that is, and ask them for the go/no-go on them. Do the bores need a hone at all? If so, you might well be justified in getting some different pistons in order to get away from the ring supply problem. Whether you're happy to spend a lot more money right now, on more gear, rather than less money, but an amount that looks stupid given that you will only get a handful of rings in exchange for that money, is for you to decide.
    • iain_ST44GA
      M35 Aftermarket Fuel Pump

      By iain_ST44GA · Posted

      also possibly backed up to my filler and shat down it! 🤣
    • Julsmadrid
      RB25 Drama's

      By Julsmadrid · Posted

      Ok so i would love some advice here please, i purchased an R33 a few months back and its had a few mods done to the engine, its an RB25det running a Master ECU, 1200cc injectors, bigger turbo, oil cooler, oil filter relocation kit, Spool H-beam rods, acl/ross pistons. When i removed the motor from the vehicle (as its getting a respray) i thought i would compression test it and these are the following results. Cylinder 1-145psi, Cylinder 2-143psi, Cylinder 3-125psi, Cylinder 4-145psi, Cylinder 5-140psi, Cylinder 6-135psi this test was done with the motor on the ground and powering up the starter motor. I dropped the sump and found broken oil squirters on cylinder 3,5 and 6. I was told my rings are probably worn so i stripped the motor completely to get a new set of rings for it. The trouble is no one has these rings anywhere and they have to be custom made by Ross over in the states and will cost about $600+$200 delivery. My question is how can i tell if my rings are at fault and if they are still ok and is this price ok for a set of rings?
×
×
  • Create New...