Jump to content
SAU Community

Flutter noise - How?!?!?

[R31][Silhouette]
 Share

Recommended Posts

drifto Collaborator

drifto

Posted
Posted

A turbo go bang as as Denton R33 put it, after constant abuse by lifting off full throttle at full boost often and overboosting. Both ways will vary between turbos in how long or when it will make the turbo go bang. It want happen because yours makes a flutter sound which normal and will be heard better when you remove the stock airbox and filter set up. Adding a front mount will change the sound in terms of duration, frequeancy and volume, but no the fact it happens or not.

My brother had a stock black top rb20 in his 31 4 door and a APEX GT Spec front mount. It had the most awsome and loud flutter. He ran 14psi with the stock ceramic turbo and never hurt it.

My 32 has a blitz BOV and because of the spring tension being higher than a stock silver top blow off valve, it doesn't open unless there is a substantial pressure increase caused by a sudden lift off under high boost. Which is when you won't it to go PERCHEW not flutter.

If you drive around normally and change gears during the spool up phase and not on boost, it makes a nice tight flutter unlike my brothers one which was loud, long and slow sounding.

A weak setting in any BOV will cause the BOV to open under moderate pressure levels giving you a single PERCHEW not the flutter maybe before you are on boost. No good for spooling up which will make the car feel laggy.

DCIEVE Mentor

DCIEVE

Posted
Posted

just set up your bov fairly tight so it only opens when your backing off over say 8psi, then you get the flutter when your taking it easy and the benefits of the bov when hard at it.

to change the sound just back of the throttle at different speeds, too easy

[R31][Silhouette] Contributor

[R31][Silhouette]

Posted
  • Author
Posted
Keep it the way it is.

They come plumb-back for a reason  :rofl:

Your car will probably stall and play up if you remove the bov.

Well last night I did what sky-rkt said and took off the bov and just placed an alluminium cut out over the hole and then put the bov back over the top and screwed it all back together, and now... It flutters! : ) It hasn't effected the way the car drives at all! Still boosts the same, revs the same! everythings the same - just a nice flutter now - that's all!

Cheers

[R31][Silhouette] Contributor

[R31][Silhouette]

Posted
  • Author
Posted
it'll be slower on the gear changes as the pressure aint going out where its meant too = hinderance in performance

Yeh maybe so - but it's not that bad that I can even feel the difference - still pulls the same through the gear changes, maybe cause it's not boosted there isn't that much pressure to get out? I dunno feels the same to me

[R31][Silhouette] Contributor

[R31][Silhouette]

Posted
  • Author
Posted
do you think it would make a diff if you cover up half or more of the hole? it would couse a bit more back pressure yet still make use of the bov???

I reckon you'll get a bit of both! but I cant imagine the flutter being all that loud?

Only one way to find out I guess..

aKTiVE Collaborator

aKTiVE

Posted
Posted

i have dabbled in this area a little bit... how to get the 'sickest cooler dose'. There is a constant debate as to whether removing all bovs will damage/reduce the life of your turbo... but basically its up to the owner whether they think its wise or not...

Anyway, on all of my cars that were turbo charged, it became obvious to me the piping/cooler size/turbo/air filter would depend on the sound of the 'flutter'.

Decent sized cooler piping, aftermarket fmic and a pod filter will amplify the sound.... but the ONE mod to me that made the sound very loud, was removing the standard plastic piping from the turbo to the airfilter/pod to a steel pipe...

I usually have bovs on my car, but they are tightened up to the sh1thouse. So 10psi and under it will flutter, and then when you release the throttle on full boost, it will flutter and bov simultaneously... sounds great =)

  • 2 weeks later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • The Bogan
      NC MX5

      By The Bogan · Posted

      Yeah, it's getting like that, my daughter is coming over on Thursday to help me remove the bonnet so I can install the Carbuilders underbonnet stuff,  I might get her to give me a hand and remove the hardtop, maybe, because on really hot days the detachable hardtop helps the aircon keep the interior cool, the heat just punches straight through to rag top I also don't have enough hair for the "wind in the hair" experience, so there is that....LOL
    • joshuaho96
      Cas issue

      By joshuaho96 · Posted

      Could be falling edge/rising edge is set wrong. Are you getting sync errors?
    • joshuaho96
      Jacks that fit under GTR lips that can reach the subframe?

      By joshuaho96 · Posted

      On BMWs what I do because I'm more confident that I can't instantly crush the pinch welds and do thousands of USD in chassis damage is use a set of rubber jacking pads designed to protect the chassis/plastic adapter and raise a corner of the car, place the aforementioned 2x12 inch wooden planks under a tire, drop the car, then this normally gives me enough clearance to get to the front central jack point. If you don't need it to be a ramp it only needs to be 1-1.5 feet long. On my R33 I do not trust the pinch welds to tolerate any of this so I drive up on the ramps. Before then when I had to get a new floor jack that no longer cleared the front lip I removed it to get enough clearance to put the jack under it. Once you're on the ramps once you simply never let the car down to the ground. It lives on the ramps or on jack stands.
    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      Nah. You need 2x taps for anything that you cannot pass the tap all the way through. And even then, there's a point in response to the above which I will come back to. The 2x taps are 1x tapered for starting, and 1x plug tap for working to the bottom of blind holes. That block's port is effectively a blind hole from the perspective of the tap. The tapered tap/tapered thread response. You don't ever leave a female hole tapered. They are supposed to be parallel, hence the wide section of a tapered tap being parallel, the existince of plug taps, etc. The male is tapered so that it will eventually get too fat for the female thread, and yes, there is some risk if the tapped length of the female hole doesn't offer enough threads, that it will not lock up very nicely. But you can always buzz off the extra length on the male thread, and the tape is very good at adding bulk to the joint.
    • Duncan
      Mistakes were made, my R34 Story

      By Duncan · Posted

      Nice....looking forward to that update
×
×
  • Create New...