ReDLiNe@t9

besides the ever delightful swish noise that is delivered from the contraption......does it do any noticable or signifigant work?......i didnt care.....i bought the hks SSqv (super Squeak) --but honestly......wats the deal....show me i did good in buying it.....

SpoolinRX

iTrader: (6)

If you have a stock turbo there wasnt really any point in buying it for anything else then just makin people that dont know anything about FD's, look at you funny and say what the **** was that noise. Belive me, when i came to this one guy in a mustsang and let my BOV go he said "Woah buddy ez on the shifting" But if you ever plan on getting a bigger turbo (with more boost) you will need it.

12ARX

Do a search on www.ausrotary.com.au for bov's and you will see many arguments...sorry discussions have risen about this apparently required device....

ReDLiNe@t9

your site doesnt work lol....o and to the guy with the first post.i dont have different turbos or a single conv. but i do have the bnr stage 1 upgrade...clipped fans n watnot

doncojones

The function of a BOV is to save your turbos when you shift. Generally when shifting a turbo car with a manual transmission, you take your foot off the gas pedal which slams the throttle shut. The turbo doesn't immediately run out of boost, so excess pressure builds up in the intake pipes which can make its way back to the turbo. If this happens often, it can shorten the life of the turbo. What a BOV does is when the throttle is slammed shut under boost (i.e. you shift while there's a decent amount of acceleration required) the valve opens up to relieve the pressure in the intake pipes thus preventing it from building its way back to the turbo.

The FD has a BOV stock. It works just fine without making any discernable noise. There is a way to disconnect a hose that will make the characteristic Fast & Furious™ BOV sound. However this does nothing to increase performance and only announces that your car is not stock to others on the street. It might get a couple of oohs and ahhs from the crowd of teenagers at the local Starbucks but in the long run it's kind of pointless if ya ask me.

12ARX

try this http://www.ausrotary.com/ look for ... no bov

Tom93R1

iTrader: (2)

Plus stock BOV's are not messy. Disconnect the hose or add an aftermarket and you will have a nice mess of oil all over everything around it in the engine bay.

ReDLiNe@t9

ahh much better..seems im a moron and for got the au thing was there.......got my thinking cap on backwards i guess

RX7SpiritR

iTrader: (1)

actually not when you shift just when you let off the gas, but this mostly happens when you shift at higher rpm's. It protects the turbos from compressor surge which is when the intake pressure goes back on the turbo compressor and stops it suddenly causing serious damage to the turbo internals. That is why you have a bov, now as to why you upgrade, its mainly for when you start setting your boost levels higher. You can run stock turbos and still NEED an upgraded bov, like when you start boosting really high as in 20+ pounds because the stock bov can't handle those high boost levels for that long (they will fail in other words). But I don't know if this is possible with stock twins, is this even possible on the bnr stage 2 or even 3's to boost to 20+? Anyone know?

Snook

iTrader: (12)

yeah 20 psi is doable on stage 3s
spoautos is running 19 daily on pump gas
he was doing fine with a stock bov

remember 19psi on twins is not the same as 19 on a big single...it flows a lot more air

ive never seen a bov wear out or break...usually the problem is that it cant flow enough raw air out but the stock ones are very very good so i see no need for an upgrade unless you have a single turbo

CRX7

Are you guys simply disconnecting them, because i did that today and i love it, because i am easily amused, but i would like to support them somewhere somehow so they are not just layign there. What did some of you do?

Toadman

Except to the cops in a smog-**** state. Any intake mod, even disconnecting the stock BOV hose from the stock airbox, can get you unwanted hood-up attention from the local Po-Po. Trust me.

blueskaterboy

what if im going to upgrade to single turbo but dont want a ricey high pitched whoosh... i just want the stock breathing sound!

DaedelGT

You could still use the stocker if you welded a bung for the piping somewhere on the intake track. It'd look kinda weird, but it'd work.

RotorMotor

iTrader: (5)

you can always feed it back to the intake like a stock one... this will keep it relativly quiet.... im planning on doing this

DCrosby

Oil in the intake to the point that it spills all over the place, is usually a sign of a turbo gone bad.. so Unless you stick your BOV at the lowest point on the hoses, you souldn't get all messy... and the Woosh sound is tuneable, and even Elliminatebale, via a recirculation pipe from the BOV back into the airbox...

Messing with you intake is concidered bad in Cali, the thing taht you can argue in court, if you're armed with the knowledge and not just talking out of your ***... is that a BOV, vented to atmosphere will change the Airflow to the engine, the thing is this engine used a MAF sensor and therefore reads Airflow, to adjust it's tune, and therefore will compensate automatically, unlike other systems...

That and it's going into the airbox, at which point it could make it's way back through the intake shroud, and back to the front of the car, (Theoretically) If going bcakwards under boost and you let off the throttle maybe

RotorMotor

iTrader: (5)

hmmm, i dont see how you could run 19psi on pump gas... shouldnt you end up with detonation because of the much higher compression ratio you are causing in your combustuin chamber? im just not understanding how you can run 91octane @19psi w/out blowing your motor. can anyone comment???

as far as the single flowing more air, im not sure if i believe that either (sorry for being such a skeptic)... if you are seing 19psi at the throttle body using a single turbo, and using some BNR stahe 3's you can also make 19psi at the throtle body (assuming both motors are the same etc) then your total air flow should be the same in either case, no?? if someone could comment i'd appreciate it. thanks heath

Tom93R1

iTrader: (2)

Even a brand new perfect condition turbo will get some oil blow-by. It is a very light mist that eventually builds up on anything that gets in its way. Venting a BOV will vent this mist and will cause some oil to build up no matter what, not to mention the environmental effects fo spraying hot oil into the air. This is why all stock cars from FD's to DSM's to Supras have a BOV that recirculates back into the intake instead of venting to atmosphere. Cars such as DSM's with a MAF instead of MAP could have been tuned to vent to atmosphere, but because of the oil in the intake the boost charge is just recycled back into the intake and the ECU is tuned to run that way.

RX7SpiritR

iTrader: (1)

I agree.

CRX7

So the ECU is factory tuned to compensate for oil in the intake???

r0t0r-rooter

Only us poor Cali folk get the 91 octane gas....
...besides, it's all in the tuning x 2

Sesshoumaru

iTrader: (1)

ugh... psi is relative

look at a garden hose

there is a nice steady flow of water.........

but u want more force b/c you tires on your car are really dirty.......

so u put your thumb over the end. This decreases the area and increases it's velocity which is realated to the force or "psi". It hits the car so hard it splashes on your shoes

The same amount of water is flowing through the hose. Just at a different psi.

a larger turbo has a bigger "hose" so it can flow more at the same psi.

It's all about the size of the hose my friends..........

RotorMotor

iTrader: (5)

but you cant tune out detonation. detonation occurs when your fuel mixture gets to a pressure that it can not withstand. thats why we have to run premium in our cars.... because it will detonate when the pressure increases (under boost). otherwise mazda would have just "tuned" the car to run at 10psi on 87 octane!!

as far as octanes are concerned, do other states have higher octanes for "premium" cause in CA the highest ive seen is 91. if so why is that?

Sesshoumaru

iTrader: (1)

that's what oil catch cans are for though.......

run the blow by through the filter

atmospheric bov should not vent oil - if setup for a recirculating bov it might.

the ecu thinks it has more air than it does (by recirc methods). That is what causes the flames at high boost levels I'm for the flames.

RotorMotor

iTrader: (5)

exactly my point a few posts up... if we are measuring the psi @ the TB for a single, and a set of twins that can both make 19psi @ the TB... then dont we have the same amount of air being pushed?