Jump to content
SAU Community

Recommended Posts

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

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...

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...

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

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.

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

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...

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...

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.

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

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

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.



  • Similar Content

  • Latest Posts

    • I've got the rear ones, they're certainly beefy. I need to take them to my driveshaft guru to check over, he's very fussy about the quality of components so I'll let you know if they are made of cheese by a blind man.   Are you in Australia? A mate just had a set of EN26 shafts made for his K20 Lotus by our fabricator which were quite cheap (compared to Driveshaft Shop) so if you can procure the CV's and draw what you need he'd make them for ~$800 for the pair.
    • Had I known the diff between R32 and R33 suspension I would have R33 suspension. That ship has sailed so I'm doing my best to replicate a drop spindle without spending $4k on a Billet one.
    • OEM suspension starts to bind as soon as the car gets away from stock height. I locked in the caster and camber before cutting off the kingpin. I then let the upright down in a natural (unbound) state before re-attaching it. Now it moves freely in bump and droop relative to the new ride height. My plan is to add GKTech arms before the car is finished so I can dial camber and caster further. It will be fine. This isn't rocket science. Caster looks good, camber is good, upper arm doesn't cause crazy gain and it is now closer to the stock angle and bump steer checks out. Send it.
    • Pay careful attention to the kinematics of that upper arm. The bloody things don't work properly even on a normal stock height R32. Nissan really screwed the pooch on that one. The fixes have included changing the hole locations on the bracket to change the angle of the inner pivot (which was fairly successful but usually makes it impossible to install or remove the arm without unbolting the bracket from the tower, which sucks) and various swivelling upper arm designs. ALL the swivelling upper arm designs that look like a capital I (with serifs) suck. All of them. Some of them are in fact terribly unsafe. Even the best one of them (the old UAS design) shat itself in short order on my car. The only upper arm that works as advertised and is pretty safe is the GKTech one. But it is high maintenance on a street car. I'm guessing that a 600HP car as (stupidly, IMO) low as you are going is not going to be a regular driver. So the maintenance issues on suspension parts are probably not going to be a problem. But you really must make sure that however your fairly drastically modded suspension ends up, that the upper arms swing through an arc that wants to keep the inner and outer bolts parallel. If the outer end travels through an arc that makes that end's bolt want to skew away from parallel with the inner bolt, you will build up enormous binding and compressing forces in the bushes, chew them out and hate life. The suspension compliance can actually be dominated by the bush binding, not the spring rate! It may be the case that even something like the GKTech arm won't work if your suspension kinematics become too weird, courtesy of all the cut and shut going on. Although you at least say there's no binding now, so maybe you're OK. Seeing as you're in the build phase, you could consider using R33/4 type upper arms (either that actual arm, OEM or aftermarket) or any similar wishbone designed to suit your available space, so alleviate the silliness of the R32 design. Then you can locate your inner pivots to provide the correct kinematics (camber gain on compression, etc).
    • The frontend wouldn't go low enough because the coilover was max low and the upper control arm would collapse into itself and potentially bottom out in the strut tower. I made a brace and cut off the kingpin and then moved the upright down 1.25" and welded. i still have to finish but this gives an idea. Now I can have a normal 3.25" of shock travel and things aren't binding. I'm also dropping the lower arm and tie rod 1.25".
×
×
  • Create New...