I hate asking, but...

[Roy]

Same old question concerning BOVs.

Not asking what performance increase etc, or who owns what, or the legalities of vent to atm etc.

What i would love to know is, if anyone has seen Best Motoring Vol 5, can someone tell me by the sound, what BOV the AMUSE Supra (the white one) is using.

Or for that matter the yellow S14 off Best Motoring Vol 6.

If someone can help great.

For those who havent seen them they are an entertaining watch, even better now you dont have to import them yourself

[BOOSTMEISTER]

I haven't seen it but chances are that it isn't the bov you can hear as most of the big jap cars use external wastegates and they can make a very awesome sound when they partially open then shut when someone is on and off the throttle. Just a guess.

[TTT]

Roy...

Please tell me if this is the sound you are refering to...

there are a couple of small files..

just download and listen..

Sounds

From what I can remember... the sound from that supra was similar to this..

[UR2EZ]

link dont work

[TTT]

ok.. let me try a different approach..

try these..

1

2

3

Can you download them by right click and save?

[poyz]

BOOSTMEISTER is correct in that external wategates do make a nice fluttering sound, but it's not neccessary.

The Yellow S14 off BM Vol 6 actually has a standard turbo. (From memory, been a while since I've seen the video). So no external gate there.

My car is equipped with a Blitz BOV (older version) and is plumbed back. The car makes a very similar noise as you hear from the S14.

Originally posted by Roy

Same old question concerning BOVs.

Not asking what performance increase etc, or who owns what, or the legalities of vent to atm etc.

What i would love to know is, if anyone has seen Best Motoring Vol 5, can someone tell me by the sound, what BOV the AMUSE Supra (the white one) is using.

Or for that matter the yellow S14 off Best Motoring Vol 6.

If someone can help great.  

For those who havent seen them they are an entertaining watch, even better now you dont have to import them yourself

[Roy]

Yeh the S14 is using factory turbo, and the Amuse Supra uses a HKS tubo with internal wastegate.

So Blitz may be the business, it definitely aint any of the HKS BOVS that have seen duty on my car.

[TTT]

Roy are you actually talking about the fluttering noise? sort of like a ssstt tt tt tt tt tt..

If so, then it is either that the BOV staying shut or it doesn't have a BOV at all.

The Blitz bovs all make a psshhh sound of some sort.

From what I can remember, that supra made a huge fluttering sound.. which would mean that he was NOT runing a bov at all or had the spring on too tight and it wasn't opening to make a noise..

[poyz]

The Blitz BOV on my car does make some sort of psshhh sound. Only under higher boost (ie 14psi and up). Under this it will make a flutter noise.

The spring on the BOV has a very high rate, I've even got the BOV on the softest setting.

[Roy]

Yeh ive heard people say you get the fluttering noise when the spring rate in the BOV is too high, but im not convinced. Not to say they are wrong, but there is too much anecdotal facts floating around.

Anyone familiar with Sports Sedans in the early 90s will remember the Peanut Slab sponsored Ford Sierra from NZ that use to come to Aus occasionally and destroy Aus sports sedans, including Keith Carlings brutal 300ZX. It like the Supra and 200 on BM DVDs made the fluttering noise, and this way a pure turbo race car, even some of the 80s touring cars (05 Btrock Seirra) made the fluttering noise.

Is it a fair assumption that turbo race cars wouldnt wind up the BOV spring to reduce its effeciancy???

[TTT]

Roy...

Those sieras of the 80's didn't run any BOVs..

Did you ever hear a psshht once from them? NO. they were constantly fluttering when off boost.

And I am pretty sure that you will find the Supra in the BM DVD doesn't run a bov either.

If you want the fluttering noise, remove the bov and get a steel plate cut to cover the hole where the bov was..

[Guest MFX_R33]

There are alot of factors DO NOT give you a BOV sound at all (internal or external). That myth has been around for years, and I have no idea how it has been kept up. As already mentioned, generally that fluttering noise is from the lack of a BOV, and it is actually the sound of the air being blown back in through the airfilter, as the turbo back spins. My car does this and you can actually see the foam filter flapping as it happens.

Blow off valves can make this noise too. This often has very little to do with which BOV you have (most BOV's have almost the same simple piston design), but where it is placed. I have found BOV's tend to make that flutter when there is a greater length of I/C pipework (generally with a front mount) and the BOV is placed closer to mid way along the pipework.

Jeff.

[TTT]

No bovs can't make that sound..

it doesn't matter where it is placed..

that fluttering sound CAN NOT come out of the opening of a bov.

The bov can only make one sound... a single release of air in one hit.. it can't open and close to make different fluttering sounds.

If you have your bov mid way along your pipes, and you are hearing a fluttering sound, it is not coming out of the bov.. it just means that there isn't enough pressure to open the bov.

If you want a fluttering sound, remove your bov and block off the holes... if you want a bov noise, fit one and adjust it so that the piston is JUST closed at idle and it will psshht every gear change..

It's not that hard.

There is no other way to get a fluttering sound from your TURBO car.

[poyz]

Really, maybe I'm deaf because my bov has been making this sound for almost 3 years now.

(edit) P.S. I know its the bov because I've had it on dyno's. I can easily see the bov shaking when the throttle is closed in accordance to the flutter. This noise is made wheter or not I recirc it or vent to atmo.

[TTT]

Poyz...

Yes.. maybe you are deaf.

The sound does not come OUT of the bov.

it comes out of the air filter... listen closely next time..

The BOV piston might bounce up and down but it doesn't open and close does it..

It doesn't matter if it is atmo or recirc... it just means that it is not opening and therefore the air is going back through the turbo and getting chopped up going CH CH CH CH CH as it goes through the turbo blades which are spinning at like 80,000rpm and the sound can be heard from the turbo/air filter area.

Some people are unbelievable man..!!!!

[poyz]

How about you come over here and visit me. I'll run an example for you.

Here's how I'll do it.

I'll start my car, put her in neutral and leave the handbrake on. I'll pop my bonnet, rev the thing to say 4000-5000rpms. Air filter makes a flutter noise. (Car didn't make boost, bov doesn't open)

Now, we do it again. This time I rev to 7500rpms. Car will build boost (<5psi), BOV opens. Two noises can be heard. One you already have heard, the air filter. The other is the BOV.

Take note of the noises.

Go for a drive, take note of the noises upon releasing the throttle, sounds exactly like the BOV.

Still don't believe me, then that's your problem.

[TTT]

ok.. I'll just leave it and say it's "my problem"

[poyz]

Yeah, besides, you can't be wrong

I've been living in a fantasy land for almost 3 years with my car

Originally posted by GTST

ok..  I'll just leave it and say it's "my problem"

[Guest MFX_R33]

GTST,

I manufacture BOV's and have done alot of R&D on the subject, and BOV's can make that sound. In my experience I have not seen a BOV mounted on factory pipework in the factory position, make that sound. I have run my car on the Dyno without the bov and you can see the RUSH filter actually being sucked in and flutterin when you back off. When the BOV is connected you can see and hear it flutter (mine is placed in an opening in the front bar the opposite side to the filter). I have also seen it on a mates TX3 where his BOV is also placed next to the I/C and it flutters.

I am also in Sydney. I am near Liverpool. I would quite happily meet up with you and prove it to you if you like.

Jeff.

[poyz]

My BOV is mounted in the factory position and in factory pipe work. I do, however, have a FMIC with extra pipe work. But with the factory plumbing to/from the BOV my car does indeed make this flutter.

Originally posted by MFX_R33

In my experience I have not seen a BOV mounted on factory pipework in the factory position, make that sound.