Can you hear your blow off?

[Little1er]

Can anyone hear their blow off valve releasing pressure? I wish I could, it sounds so sexy!!

[Dak Tirque]

I hear mine...I assume it's the "blow off". A nice swoosh sound after a hard acceleration. It's pretty cool! Does this sound get louder when the boost is increased by a tune?

[Mr. Clarkson]

Do they actually have BOV and not DVs?

[1SerieStud]

I believe these cars have DV's, but definitely more audible in the N55 cars. I can hear mine too.

[MarkR171]

Loud and clear, yes.

[thez99]

I have a ER chargepipe with the HKS SSQV bov with the purple insert. It isnt loud but you can hear it under harder pull in gear. But its not something you're gonna hear thru every shift all the time. Those who drive MT who tend to let off the accelerator more between shifts will hear it more. I have the steptronic, the valve lets off the pressure between shifts but not as hardcore as it would with MT I guess. I hear it best when revving at idle or pulling WOT in 3rd, 4th n 5th.

Its still doing its job all the time, you just hafta remember that the main reason you really hear that pshhh is when boost is at full and that usually only happens under WOT in gear or like I said idle reving. Typical around the street driving I hardly ever hear it, and of course I dont drive like bat outta hell round my typical commutes, etc. Unfortunately for me i dunt have alotta areas where I can really open it up confidently. Hope to change that soon

[thez99]

Originally Posted by 1SerieStud

I believe these cars have DV's, but definitely more audible in the N55 cars. I can hear mine too.

If you're hearing anything with the stock setup, N54 or N55 its just the turbo spool or engine noise. DV's will not make noise unless its an open valve/spring controlled aftermarket setup, much like Forges, etc.

[lithium1330]

Curious, does the BMW engine management measure air intake into the system? And if so, wouldn't the use of the BOV affect it as the BOV effectively "dumps" the measured air outside the system as oppose to re-circ via the DV. I ask because the I know some Audi/VW guys do this... While you can use the BOV on modern turbo cars, you car ends up running rich as the computer calculates the fuel/air mixture based on what's coming into the a "closed" system. Thoughts?

[Little1er]

^^^I can hear the turbos spooling and sucking in air, but I never hear it dump like in an EVO or STI (only experiences in other turbo cars). If you put an actual BOV will you hear the common "dump"?

[MarkR171]

Originally Posted by thez99

If you're hearing anything with the stock setup, N54 or N55 its just the turbo spool or engine noise. DV's will not make noise unless its an open valve/spring controlled aftermarket setup, much like Forges, etc.

Firstly, I'm not an expert nor do I claim to know much about BOVs/DVs/their function or how they work, but I can tell you I can hear the turbo spool and the release when I abruptly lift off the throttle. It's not loud like an aftermarket BOV on an STi or EVO, but to me, it's the same sound, just quieter.

[ErvGotti]

Originally Posted by lithium1330

Curious, does the BMW engine management measure air intake into the system? And if so, wouldn't the use of the BOV affect it as the BOV effectively "dumps" the measured air outside the system as oppose to re-circ via the DV. I ask because the I know some Audi/VW guys do this... While you can use the BOV on modern turbo cars, you car ends up running rich as the computer calculates the fuel/air mixture based on what's coming into the a "closed" system. Thoughts?

BMW uses an TMAP instead of MAFS sensor. It judges pressure instead of volume allowing us to use BOV's without a problem. Alot of people run BOV's on the N54

[ErvGotti]

Originally Posted by MarkR171

Firstly, I'm not an expert nor do I claim to know much about BOVs/DVs/their function or how they work, but I can tell you I can hear the turbo spool and the release when I abruptly lift off the throttle.

I can hear the DV's opening to recirculate the air on my N54. Not as loud as a BOV though

[thez99]

Originally Posted by ErvGotti

I can hear the DV's opening to recirculate the air on my N54. Not as loud as a BOV though

You wanna know why you cant? #1 DV's do not make noise while recirculating. #2 The stock DV setup has a resonator near the TB that eleviates even the little bit of noise the DV's would make at WOT which is nill. The noise you are hearing is the intake and turbo spool, not the DV boost. Ive driven and heard several different turbo cars, this is pretty much the same deal with every stock turbo setup, cept maybe an EVO or somethin.

[Sylon]

I have an N55 and I love hearing it. I can only hear it when the windows are down though. I can clearly hear the turbo spool up and the pshhh sound when I switch gears if very noticeable when the windows are down. If I could figure out a place to mount my camcorder without the wind drowning out the noise I would record it. But the slightest damn breeze sounds like a hurricane on my camcorder.

I test drove an N54 before buying my N55 and I can say the spooling and the pshhh is more noticeable in the N55.

[1SerieStud]

Originally Posted by thez99

You wanna know why you cant? #1 DV's do not make noise while recirculating. #2 The stock DV setup has a resonator near the TB that eleviates even the little bit of noise the DV's would make at WOT which is nill. The noise you are hearing is the intake and turbo spool, not the DV boost. Ive driven and heard several different turbo cars, this is pretty much the same deal with every stock turbo setup, cept maybe an EVO or somethin.

You wanna know why YOU can't hear it? Because it's actually not noticeable on a car with an N54 engine. Go drive a 135i with an N55 and then we'll talk

[MarkR171]

Originally Posted by 1SerieStud

You wanna know why YOU can't hear it? Because it's actually not noticeable on a car with an N54 engine. Go drive a 135i with an N55 and then we'll talk

I'm no expert, but I'm pretty sure I know what I'm hearing. IIRC, you can hear it in Sylon's video he made after doing the "golf tee" mod

[Xylarax]

I'm also no expert, but I will say the same things others have said. In my n55 if I have the windows down i can hear an unmistakable psshhhh sound on the upshift at high RPMs

[Top Gon]

you can kiiiiinda hear it if you have DCIs and you let off the gas after wot. completely stock though? cant hear jack.

[1SerieStud]

Originally Posted by Basheezy

you can kiiiiinda hear it if you have DCIs and you let off the gas after wot. completely stock though? cant hear jack.

Again, you have an N54 motor, which is why stock you can't hear jack

[egainer]

I'm going to agree, I can hear it in my N55 with windows down. Especially if you are near a line of trees or something to help bounce the sound back to you. It's very quiet, but there, and easier to hear if you are in WOT

[SlicktopTTZ]

Ok, y'all must be deaf because I could hear the recircs release into the intake on my n54 stock. Don't tell people that they CAN'T hear it just because you don't know what to listen for.

Then, buy a tune, DCI and leave your cowling off. Sound like a breathing, sneezing, jet monster!

Synapse Synchronic coming up soon!

[imported_mega]

I can hear it on my n54 but only if I'm passing and was almost at redline and between gears when the car I'm passing is right next to me

my car is bone stock