Kinda nervous-blitz ss BOV flutter/woosh

[mr.nismo.]

I've had my sr swap in for a year now and my blitz ss BOV has always made a fast " choo-choo-choo" and it's 100% atmosphere. I thought that's how it sounded since my wide band reads a rich condition every time it goes off. However I was on YouTube and saw every SS BOV woosh, no flutter. I know they're are two different springs that it can come with so I assume I have the stiffer one, however since it's technically it's doing it's job I should be fine? Wait. If I rev it up enough (I have an ARC induction box) I can see the filter flex back and forth a little with the BOV as it goes off. That's compressor surge then isn't it. Fuck

[Ichiban4]

A stiffer spring will obviously cause more compressor surge. That being said you can read into it if you want but tons of people run really stiff/no BOV. I've run mine very stiff for a long time now. Sounds cool and feels better.

[mr.nismo.]

I thought it wouldn't be that bad since my wideband dips really rich when it goes off, I'm just not sure HOW BAD it could be chopping at the turbo

[zerodameaon]

Turbo flutter is bad, and sounds like shit. Adjust your BOV so all you have is a solid woosh like you should, less strain and you are not having to respool your turbo from a stop. SRT4 kids love that flutter sound, do you really want to be SRT4 cool?

[mr.nismo.]

Kind of hard to adjust when it's just a 10 bolt. The stock adjustment is gone

[zerodameaon]

So change the spring, that's adjustment is it not? Or go get a BOV that will work better for your setup.

[Frank_Jaeger]

I don't like the way turbo flutter sounds, and neither should you. This is my prime reason for preferring BOVs. I believe running no BOV will significantly decrease spool time, however I will ignore the undeniable benefits to throttle response when you maintain boost between shifts. I read on the internet that turbo flutter (which I easily confuse with compressor surge) causes significant damage to the turbo, even though I can't find a single test conducted on the matter. I can't even give a basic rudimentary estimate of how much a turbo's life will be decreased by not having a BOV. I ignore anyone who claims to have run hundreds of thousands of kms without a BOV on over 10psi of boost on OEM turbos.
I concur with everything said here.

:trogdor:

[mr.nismo.]

I have a BOV it just makes a flutter sound v a woosh sound. I changed the bolt for a short one so well see how it reacts after I bleed it

[zerodameaon]

I concur with everything said here.

:trogdor:

Your a winner, if you want to attack something come right out and do it. Also I know the differences and did not really care to differentiate between them because they sound pretty similar. Either way both should be eliminated.

[mr.nismo.]

I put a short ass bolt in there and it still flutters. But it wooshs when revving now whereas it didn't before. I'm running 10 psi.

[Frank_Jaeger]

Your a winner, if you want to attack something come right out and do it. Also I know the differences and did not really care to differentiate between them because they sound pretty similar. Either way both should be eliminated.
Excellent. Now I will instill within you the virtues of dose pipes. Join us.

[Mikester]

First, is your BOV the oldschool Blitz SS, or the newer, SS-DD? I have the old SS and love it. I don't give 2-shits about whatever 'SRT cool' is... I've had this BOV since my old 180SX and intend to keep it till it's no longer of use. I like the whoosh & the slight flutter sound that follows.

If you bought it new, then you may disregard this (or not)... The BOV is extremely simple, and sometimes, stuff gets between the piston & wall where the seal is. Without needing to replace the spring, you can dissasemble the BOV & give everything a good clean & lube to ensure nothing is causing it to hang up... I've had my BOV stick closed before- causing what you are describing.

http://farm9.staticflickr.com/8224/8417706577_5d5396121b_b_d.jpg

No need to get the upgraded spring- this is for higher boost applications and will only make it not open as easily... and due to the larger/longer spring, the piston does not travel as far (opens less)... If you're only running .7 - 1.2bar, the OEM spring is your best bet.

http://farm9.staticflickr.com/8095/8417705393_e55330e66c_b_d.jpg

^^As you see, the upgraded spring is pretty monstrous! Needless to say, I run the upgraded spring (boosting 25+psi) and the BOV opens just fine at 1.0bar, as well as 1.6... The majority of the sound is the whoosh... but toward the end of the cycle, there will nearly always be a little bit of ch-ch-ch as the vast amount of pressure has bled off to atmosphere; but there is still the remnants in the system that were not of significant pressure to open the valve- This is normal; and the only way to avoid this is to recirculate.

Either your BOV needs to be adjusted 'looser', or it may be hanging closed due to debris in the chamber. A little bit of flutter is nothing to worry about- A lot of it is.

This 'flutter' is not compressor surge; it's just flutter as the pressure in the charge piping stabilizes. Compressor surge happens for reasons other than a BOV.

[mr.nismo.]

It's the old school blitz SS. And I've already cleaned it (though there wasn't much to clean really) but I have the smaller spring in there. It's adjusted loose. If I rev itl woosh, and make a flutter when letting off boost. But air is defiantly being released

[Mikester]

^^Then you are probably overthinking it. Nothing you do will completely stop the fluttering between gears... and don't get too hung up on your wideband reading rich when this happens- there is a temporary imbalance between air/fuel demand during blow-off/spool-down.

[mr.nismo.]

I know about the running rich for a second because it's venting to the atmosphere already read by the maf. That's why I was never worried about it before. Then I saw lots of blitz ss videos and not one made a flutter sound so I was a little worried, thanks mike! Hey once I get my k27 on maybe we can hit the strip ;)

[Mikester]

Here is a video from inside my 180SX... Listen closely and you'll hear the turbine fluttering here & there.


ykvvhKJ5Rdo


My work computer is weird- If I failed at posting the vid, here is the link: http://www.youtube.com/watch?v=ykvvhKJ5Rdo

[mr.nismo.]

There's wayyyyyy more flutter in mine. If I let it hit full boost and just let off it's a lot of flutter. I'm guessing u should post a vid lol

[mr.nismo.]

I know this was horribly delayed mike but the stuff ass spring is what's in it lol. The pictures wernt loading before but looking at it the red one is defiantly in there. I guess I'll try to cut it for the time being?

[mr.nismo.]

I just threw it in w/o cutting.works fine now

[!Zar!]

Turbo flutter is AWESOME.

It sounds like the doves of Jesus having a conversation with Birdman.

People love to cry about how it damages the turbo.

I've never had any issues due to compressor surge.

[KevinEdgar]

Turbo flutter is AWESOME.

It sounds like the doves of Jesus having a conversation with Birdman.

People love to cry about how it damages the turbo.

I've never had any issues due to compressor surge.

Thank you. I love driving my car around and hearing the surge, I will probably never run a bov.

[Kingtal0n]

fwiw a push type like the greddy type-s (rest it's soul) when set to it's weakest setting and installed on the hot side (close to the compressor) will never cause surge (because it hangs open even at idle).

the only reason not to run a bypass valve is if your demand for performance outweights the risks. In other words, in a competition setting, you want results and minimize failures. that said, having a bypass is an unnecessary risk in a competition, because you care less about protecting the parts, and more about winning.

In a daily driver setting, you want the bypass because it will extend the life of the turbocharger. :wavey:

[pancakes562]

Check for any air leaks?

[mr.nismo.]

Check for any air leaks?


It's been fixed for a little over a week now, everyone's just getting their .02 in lol. Thanks though