Another Bov ?

[abu]

that is old skool

been around for like 5 years.

why would you buy it when you can get a screw and stick it in there yourself?

the little hole is there for a reason.

it helps to open and shut the bov faster.

if it's blocked, the car feels a little more jerky on the transition point from boost to vacuum.

as in when you back off from the accelerator in a gradual fashion (like when you drive on the street)

I meant in the sense if you dont have a stock BOV and want to go back to one which is able to hold slightly more boost..

BUT, that being said, where do you stick the screw?

[TTT]

see in that guys pics of the bottom of the bov..

there is the large circle in th emiddle (the piston that is effectively the bov.. it opens and shuts) and then to the side there is a smaller circle.

that is the screw he has put in there.

a small wood screw does the trick.

if that bov wasn't modifed, it would look like the bov on the right in this pic.

http://herpetology.com/dsm/bov10e.jpg

[abu]

see in that guys pics of the bottom of the bov..

there is the large circle in th emiddle (the piston that is effectively the bov.. it opens and shuts) and then to the side there is a smaller circle.

that is the screw he has put in there.

a small wood screw does the trick.

if that bov wasn't modifed, it would look like the bov on the right in this pic.

http://herpetology.com/dsm/bov10e.jpg

Got it! Sharpkunt.

Thanks

[Gazee]

not having a bov will not break the back wheel of your turbo.

if anything, it's the front wheel that "could" be damaged.

i think it depends on the boost your running n stuff but saying it wont damage your turbo is a bit of an understatement, especially the ceramic/ plastic wheeled ones

[JVP]

lol @ andru. again.

i once had an atmo bov on my old 32. twas shite. went back to stock, so much better.

waste of 300 bucks. yes i was young and stupid, n00bish if u will.

thanks,

jarryd.

lol

[Oblivion]

This was a good read this thread, the right amount of BS and info.

LMAO @ chicks getting wet.

but just to say, that my cars does still back fire and spits flames on stock. i was considering getting a aftermarket plumb back system to suit my r32 gtst. just for wank factor and new noise, but then blocking off the BOV is good too

as for damage being done to your turbo without having a BOV, yes that is correct, not to the wheels...but to the bearings in the turbo.

Edited August 23, 2007 by Oblivion

[TTT]

i think it depends on the boost your running n stuff but saying it wont damage your turbo is a bit of an understatement, especially the ceramic/ plastic wheeled ones

no bov/tight bov = flutter right?

flutter is the caused by the air that was SUPPOSED to be released from the bov.

the air that went in from the air filter, through the FRONT wheel of the turbo, through the intercooler, to the throttle, that was supposed to come out of the bov when the throttle shut, has no where to goexcept back the way it came.

therefore, through the intercooler, through the FRONT wheel of the turbo, past the AFM... etc.

so, the air pressure that reversion (flutter) puts on the turbo is only one the front wheel.

Skylines turbo's have ceramic EXHAUST wheels and steel front (COMPRESSOR) wheels.

Series 2 r33 gtst and R34 gtt's have a ceramic exhaust wheel and a plastic (some form of plastic anyway) compressor wheel.

the wheels are connected by the one shaft.

You know when you buy a second hand turbo and people always say "it's got minimal shaft play" etc..

well there are 2 ways there could be play.

side to side, or in and out (thrust).

there is always some play in turbo's.

when the turbo is boosting, it is sucking in the air and therefore it is pulling the wheel/air INWARDS.

when you back off, it goes back to spinning freely.

if you have no bov, the "reverting" air pushes against the turbo's COMPRESSOR wheel to try and escape.

this push of air, thrusts the compressor wheel OUTWARDS.

Long duration of this or high boost and this constant push pull on the compressor can wear it out and eventually cause the compressor wheel to touch the housing due to how much shaft play it has.

and as you can guess, a turbo spinning at 100,000rpm + reversion + time = 100,000rpm spinning wheel hitting static compressor housing... could cause chip, could cause complete failure.

one of the STI's stock turbo (VF22) is very well known for not liking to be fluttered.

[Gazee]

LOL

but in the other post you said it wont damage it, or "could" damage it.. now your explaining exactly how it WILL damage it

so the conclusion of blocking a standard 33/34 turbo will damage the turbo... correct?

[TTT]

no..

all of the above "COULD" happen.

different turbo's have different tollerances.

they are not all built to the same specs (VF22 example).

Point was that a damage that MIGHT happen by no bov/flutter would only be to the compressor wheel.

it will not be the cause of broken exhaust wheel.

ceramic exhaust wheel breakage is always due to a combo of heat and turbine shaft speed.

these 2 cause the epoxy that holds the exhaust wheel to the shaft to delaminate let go.

that's why as a general rule, people say not to boost stock skyline turbo's past 12psi.

as any more than that on a stock turbo (example rb25 with stock turbo), and the heat generate is alot more, and so is the speed at which the turbo has to spin to create the set power/boost.

[Gazee]

dude... your saying it will

and now your saying it wont...

i say make your mind up

[TTT]

I say stop trying to spin my words and take in the point that flutter will NOT DAMAGE THE EXHAUST WHEEL as you have said.

[Gazee]

I say stop trying to spin my words and take in the point that flutter will NOT DAMAGE THE EXHAUST WHEEL as you have said.

your saying they're connected together, over time it can cause it to have shaft play, etc etc

so what does that mean? the front one shits itself and the rear one stays intact?

i'm saying that they both can be damaged because i've had it happen to me, i had no exhaust wheel nor a comp wheel left

and i'm not spinning your words, your just contradicting yourself in what your saying... theres a difference

[TTT]

Yes, if one breaks the other CAN still stay on.

and yes, they CAN both break off.

how can you say that the flutter was the cause of the breakage on your turbo?

you can't.

One of my previous cars was a an ex-rally tx3.

no bov.

15psi

30,000kms on the same turbo without a breakage.

[JVP]

flutter = sausage lover?

[Gazee]

and yes, they CAN both break off.

thanks for that...

how can you say that the flutter was the cause of the breakage on your turbo?

you can't.

so its just coincidence that it happend immediatly after i blocked it?

[Rekin]

no..

all of the above "COULD" happen.

different turbo's have different tollerances.

they are not all built to the same specs (VF22 example).

Point was that a damage that MIGHT happen by no bov/flutter would only be to the compressor wheel.

it will not be the cause of broken exhaust wheel.

ceramic exhaust wheel breakage is always due to a combo of heat and turbine shaft speed.

these 2 cause the epoxy that holds the exhaust wheel to the shaft to delaminate let go.

that's why as a general rule, people say not to boost stock skyline turbo's past 12psi.

as any more than that on a stock turbo (example rb25 with stock turbo), and the heat generate is alot more, and so is the speed at which the turbo has to spin to create the set power/boost.

This happened to my friend;

14psi + standard rb20 turbo + flutter + couple of drags

=

I kept the ceramic bits and are sitting next to my PC

[Gazee]

LOL

[Hillzy]

gotta laugh at all of this

[robots]

A31 didn't have bov from factory. So why can't we just plumb back ? What is going to happen ?

[TTT]

nothing happens.

you can plumback.

I don't get what you mean.

you will need a plumback bov, a return hose, and modify your intake between AFM and turbo to be able to plumb the bov return line in to.

Or just buy a skyline intake pipe which already has the return line on it.