Blocking The Bov

[4AL2NV]

Hi i know this has been spoken about many times but i can't find anything to directly answer my questions. So if you do know previous threads please let me know the links to them and don't just say its been said before.

1) Does it affect the performance of the car?

2) Does it do perminant damaged that will stay even if i unblock it? And what is this damage???

3) Does the flutter get quieter as time goes on?

Thank you in advance.

Edited February 11, 2007 by 4AL2NV

[BAMR33]

1) Yes, for the worse.

2) Yes it will.

2.5) Back pressure on turbo, damage to bearings and compressor wheel.

3) No, nothing changes.

Do a search in future

[Kinks]

Everyone has a different opinion on this. Personally, I bought an R31 w/ RB20DET off a guy who had taken the BOV off, and it made filthy compressor surge noises while running 14psi of boost. I drove it like that for 2 years (on the standard turbo!), then upgraded the turbo for an R33 S2 item because I felt like it. Ran that for another year on ~10-12psi boost with no BOV and it was fine.

That said, a proper recirculating BOV helps reduce lag between gear changes. Since my current car is standard I'll be leaving it as-is. But on the R31... it sounded wicked and didn't hurt anything.

[dead32]

why would you want to? for the sound? get pod filter

[sh@un]

why would you do that?

you like compressor stall between gears?

just recirculate the vented air back to the low pressure side of the intake between the a/f meter and the turbo if you don't like the noise.

[Kinks]

I still miss the noise it made.. it was that good

[Cubes]

1) Yes, for the worse.

2) Yes it will.

2.5) Back pressure on turbo, damage to bearings and compressor wheel.

3) No, nothing changes.

Do a search in future

Pure speculation.. Says who? Turbosmart and people flogging their products?

----

I've found no bov reduces lag between gear changes. Thats before and after. My assumption is that it must take longer to fill the IC and its piping than it does to bring the compressor back up to speed. Thats also assuming the pressure spike created due to no bov does reduce the compressors speed 'slightly'.

Its a falacy that the compressor stops/stalls or spins backwards.

Regarding drivability.. I've found no bov to cause the car to stall under some circumstances and pop/overfuel more when coming off the throttle. Apart from that the performance aspect its definitely worth while, I currently run WITH a bov because I don't like to blow flames at the cop car behind me nor do I like stalling.

Its possible a tune can prevent the pops and stalls, it was previously (Ceffy's, VLT's, XR6T (running high boost yes can their bovs) so I don't see any reason why it cant now.

Take it from a professional in the industry not the mega buck companies trying to flog off their product to you.

http://autospeed.drive.com.au/cms/A_1457/article.html

This has been covered to death and your answers have previously all been answered.

[GTAAAH]

1) Yes, for the worse.

2) Yes it will.

2.5) Back pressure on turbo, damage to bearings and compressor wheel.

3) No, nothing changes.

Do a search in future

1) Alot of people say that it reduces lagginess between gear shifts and i definitely noticed this, lost all stuttering when i was changing and it seems to have more revs on hand/harder go after changes

2) no it will not have any large effects, i have never seen proof of any excess wear (it's hard to prove, but even comparing turbo life between models with or without a bov, theres very little difference) If there was any wear it'd be on the comp wheel, but as i said theres not a noticeable amount of difference

Also theres like a 15 page topic on blocking off BOV's you should probably read, majority of arguments are for blocking it off (from a performance aspect) but then there are alot of arguments against blocking it off (the sound)

If you want alot of sound = POD if you don't want much = Stock airbox

[BHDave]

from personal experience over the last few years;

1) Not that i've noticed

2) Not that i've noticed

3) Not that i've noticed

Turbo 1, GCG highflow, on for about a year with 14 psi running through it no bov. removed it and it was perfect. No thrust movement, the usual minimal side to side movement.

Turbo 2, HKS t300s, been on for about 18 months now. originally ran 20psi and no bov. checked occasionally for thrust and lateral movement. nothing worth mentioning. I now run a type R bov recirced and that doesn't open unless I'm running more than 1bar. Checked the turbo again about a month ago, still fine.

The only problem you'll run into if you don't put a BOV on is stalling when pulling up if you have a very short, small capacity, inlet pipe.

[Ryanrb25]

I bloked mine off recently coz i can. really just outta curiosity and bordom. It drops the revs to the point of near stalling when working with low revs, ie. reversing slowly etc...pops flames and is making a dark patch on the rear of my car hehe.

not blowin wind up anyone's arse, i found the car a bit more punchier with it blocked off....strange coz my last rb25 was opposite. got worse and was better with it unblocked.

my two bob.

[BAMR33]

Pure speculation.. Says who? Turbosmart and people flogging their products?

----

I've found no bov reduces lag between gear changes. Thats before and after. My assumption is that it must take longer to fill the IC and its piping than it does to bring the compressor back up to speed. Thats also assuming the pressure spike created due to no bov does reduce the compressors speed 'slightly'.

Its a falacy that the compressor stops/stalls or spins backwards.

Regarding drivability.. I've found no bov to cause the car to stall under some circumstances and pop/overfuel more when coming off the throttle. Apart from that the performance aspect its definitely worth while, I currently run WITH a bov because I don't like to blow flames at the cop car behind me nor do I like stalling.

Its possible a tune can prevent the pops and stalls, it was previously (Ceffy's, VLT's, XR6T (running high boost yes can their bovs) so I don't see any reason why it cant now.

Take it from a professional in the industry not the mega buck companies trying to flog off their product to you.

http://autospeed.drive.com.au/cms/A_1457/article.html

This has been covered to death and your answers have previously all been answered.

Well...

I just got Own3d.

[fun33]

its like keeping your mouth closed while you sneeze! give it a go - it f**ks you up, just like it will f**k up those turbos!

[markimak]

why would you do that?

you like compressor stall between gears?

just recirculate the vented air back to the low pressure side of the intake between the a/f meter and the turbo if you don't like the noise.

haha i like ur avatar.. thats my useful input on this..

but why would u want to block it off?

[Cubes]

its like keeping your mouth closed while you sneeze! give it a go - it f**ks you up, just like it will f**k up those turbos!

my other half does that.. Makes bugger all noise. Be stuffed I could ever do it. :S

I let out a hell loud aaaaaaaaaaaaaaaaaaaaaaaaaaaahhhhhhhhhhhCHHHHHHHHHHOOOOOOOOOOCHHHHHHOOOOCHHHHHHHO

O!!

[Pauly33GTS-t]

I was under the impression that you can buy a specific BOV blocking plate. I have my Blitz BOV but I don't want to block off the thick return pipe. Where can you find these blocking plates for the stock BOV?

[Freddy Kruger]

all you need to do to block the bov is get a empty can of whatever and then take off you bov and trace it onto the can and cut it out. then just block the vac hose and flutter like a fully sik vl bruddaz.

note on an r33 youll have some fun. itll stall on low revs and black shit will come out the exhaust on gear changes. try and pull into a park in the city and then stall. you lose you power steering and then you on you unassited brakes trying not to hit the car next to you :S good luck

[Pauly33GTS-t]

It doesnt matter that I have an Aftermarket BLITZ BOV? Why the hell would I need 2 BOV?

[Gazee]

Pure speculation.. Says who? Turbosmart and people flogging their products?

Good point... It can damage a standard ceramic turbo tho... blew my ex wheel and comp wheel clean off...

But its all personal preference with the noise n shit... some sound good, the ones with fat ass intercoolers... some sound ghey like u wana kick the prick driving the car in the teeth.. but if you like attention like going to brunette to blonde they go for it

[Rolls]

Ive got a HR31 with a rb20det that came from the factory with no bov and flutters all day long.

No performance issues, no problems.

I suggest this thread is closed with a link to the previous one.

Edited February 28, 2007 by Rolls

[illusiVe]