hrrrrrrmmmm pffffooo, hrrrrrrmmmmmm pfffffooooo....

 

Thats basically what a TT should sound like with BOV's yeah?

 

Had a test drive in a car with some unknown BOVs fitted direct inline with the hoses, but they were dead silent. Like, not even the slightest hint off any sudden release of pressure when lifting off the accelerator.

 

Could this just be that whoever fitted them didnt want to draw attention, or is it somethin I should investigate more thoroughly. The engine pulled strongly and was clearly building boost, but I was a little disappointed when it failed to announce that boost was being dumped.

 

whats the worst case scenario here? Ive driven a few TT's all at different states of tune, and this one wasn't the quickest, but its not a symptom of something more serious I hope.

 

Has anyone else got after market BOV's that operate near silently? And if so, why change them from the stock items in the first place? I know some people like to be descreet, but surely a dump valve performs a pretty limited job really; once the valve reaches a certain size it must be able to dump pressure within 99% of the time that a bigger valve would allow.:blink:

 

All opinions/comments welcome

 

thanks

Depends what boost the chap was running and what boost the bovs are set to go off at i imagine.

Maybe the recircs were still connected as well as the bovs, common mistake.

 

Jeff TT

Excuse my ignorance, but how does that work?

 

I imagined that the BOV would let boost get dumped as soon as you lifted the throttle, irrespective of boost pressure at that time.. If the boost isnt required a bypass valve opens and away it goes?

 

As you may well guess, turbo's and stuff are a new ball park for me..

 

cheers

Tell me more about recircs please...!

 

Cheers Jeff

might be baileys DV26 BOVs, had one on my 406 turbo, that you couldn't hear as it wasnt very loud.

As the zed is fitted with re circ BOVS as standard, obviously they don't make anay noise.

Some peeps when needing new ones, buy aftermarket re circ BOVS, reason being is they ain't interested in the tshhh farting sound.

smithy

I still have my recircs fitted, but with Blitz bovs. Thats only because I havent got round to blanking off the recircs yet. Can still hear the Blitz's though.

Thanks for the input,

 

As long as it isnt adversely affecting function or performance then its not gonna be a deal breaker.

 

Seems that there's a clear division between those who like car farts and those who dont!

 

Guess the novelty wears off after a while, eh?

 

Once again, thanks for the advice

I didn't realise the noise of a Scania airbrake release was in anyway novel. ;) Apart for my dislike for the useless things, they are actually detrimental to the performance of a Z running stock management.

 

They are dumping metered air in an operation for them to make their silly noise and will cause rich running, hesitation and a delay in boost pressure...not always noticeable, but because the ECU is working on the premise that any unused air is recirculated via the recirc valves, the above can always be expected when running stock management.

 

People have also been even more silly and fitted them to an auto....please don't tell me it was an auto you were driving? :rofl:

 

A BOV will only operate when the accelerator pedal is released when running positive boost pressure! This doesn't happen on an auto.

 

There is definitely no performance gain from fitting BOVs. Infact the opposite.

 

A bit of wastegate chatter is what you wanna hear. A far more serious and meaningful noise....and it's naturally produced. :)

 

I eventually want to replace my recirc valves with brand new Bailey DV30s which are aftermarket recirc valves. Do exactly the same job as the stock recirc valves, just new, more responsive and with no chance of ever getting any goose honk.

 

Edited May 2, 201015 yr by FunkySi

I didn't realise the noise of a Scania airbrake release was in anyway novel. ;) Apart for my dislike for the useless things, they are actually detrimental to the performance of a Z running stock management.

 

They are dumping metered air in an operation for them to make their silly noise and will cause rich running, hesitation and a delay in boost pressure...not always noticeable, but because the ECU is working on the premise that any unused air is recirculated via the recirc valves, the above can always be expected when running stock management.

 

People have also been even more silly and fitted them to an auto....please don't tell me it was an auto you were driving? :rofl:

 

A BOV will only operate when the accelerator pedal is released when running positive boost pressure! This doesn't happen on an auto.

 

There is definitely no performance gain from fitting BOVs. Infact the opposite.

 

A bit of wastegate chatter is what you wanna hear. A far more serious and meaningful noise....and it's naturally produced. :)

 

I eventually want to replace my recirc valves with brand new Bailey DV30s which are aftermarket recirc valves. Do exactly the same job as the stock recirc valves, just new, more responsive and with no chance of ever getting any goose honk.

 

 

 

can you supply facts that it reduces performance for the 300? As well, you always read that they can be good and bad for a car. I assume you mean without a re-map etc its not good for the zed?

 

I eventually want to replace my recirc valves with brand new Bailey DV30s which are aftermarket recirc valves. Do exactly the same job as the stock recirc valves, just new, more responsive and with no chance of ever getting any goose honk.

 

 

Si - my recirc valves are soon to be replaced by JeffTT, as he reckons they are not working properly. I have noticed recently at certain boost levels a noise of which i was trying to find a description for, and your term goose honk describes it perfectly. What is this goose doing in my engine???

 

What i mean is what is causing it? Oh yeah and how much are up-rated aftermarket valves? Or will refurbished stock ones be ok?

 

Cheers

 

What i mean is what is causing it? Oh yeah and how much are up-rated aftermarket valves? Or will refurbished stock ones be ok?

 

Cheers

 

A build up of crud.

 

I'm not aware of any successful refurb work that can be done with them. It's the diaphram that goes. I know Jeff has pulled them apart. I'll try and find the thread.

 

can you supply facts that it reduces performance for the 300? As well, you always read that they can be good and bad for a car. I assume you mean without a re-map etc its not good for the zed?

 

I've just given you the facts ya muppet! LOL ;)

 

No, a remap doesn't stop the ECU not reading any metered air! A remap only changes fueling. You need stand alone management for that.

Edited May 3, 201015 yr by FunkySi

Here we go. Interesting read. Clicky

tshhh farting sound

 

 

:rofl::rofl:

 

Best description of a bov to date...

I do have atmospheric DVs installed in my car and although I like the noise I don't get too over-excited about it thinking they give me 800bhp. Si is right in that they can be detrimental to performance, but I would venture to say only slightly and any modification that gives you a few extra ponies under the bonnet should be enough to make up for it. I think most air/fuel ratio controllers like the Apexi SAFC2 have settings that allow you to program it not to fuel as much when you take your foot off the gas in an attempt to reduce that bit of over-fuelling.

 

 

...or you could have the best of both worlds with an electric DV and your recircs in place :punk::punk::punk: :slap::slap::slap:

 

[YOUTUBE]u1jpJppnseI[/YOUTUBE]

Fake dump valves are hilarious. Imitating something pointless is just the biggest waste of time evAr! :rofl:

...not if done properly :slap:

 

http://www.youtube.com/watch?v=p_8bo_Kfhxs

 

 

 

 

:rofl::rofl::rofl::rofl::rofl::rofl::rofl:

 

 

in fact why stop with just the DV sound when you can sample the whole car:

 

 

 

 

...or why stop with a car when you can have a PC cooling fan act as a turbo for your bike:

 

http://www.youtube.com/watch?v=_ASkBJ_YCQw&feature=related

 

FFS!!!!!

Edited May 3, 201015 yr by EvoluZion3

ohh that pug is funny why do these kids insist with them! and goose honk think i have one of those aswel actually rather an angry goose that appear at the top end of the rev limit before gear change and only when im booting it from low speeds like if i pull from 20mph it will kick off at about 50 or 60 maybe

Wastegate Chatter sound for me.. blank all those damn bov's off and turn up the boost a little TSCH SHH SHH SHH SHHH .. To be honest though it's a little quieter than the average atmos bov and doesn't result in the same flameage out the boot, but then I also haven't noticed any loss in performance (or gain - which is fine and expected). I used to have an S13 with a blitz SS I believe and a stock exhaust with a cannon on the back (all fitted by previous owner), and sorry to say but it was awesome, touch the throttle in 5th at 3k revs and let go BOOOM out the exhaust!