Blocking Off Bov

[MP_R33]

SUTUTUTUTUUTU

[SLED]

lol at these threads.............can you say lag monster!..........everytime you take your foot off the loud pedal your wheel will virtually stop......unless you like to flat change everywhere.

Listen to Chad....Post #15

[SLED]

here you go Fabs.....be quick

BOV For Sale

[gtrkiet]

zsuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu tudu du du du du cshhhhhhhhhhh

[IZZMO 33]

i blocked off my stock BOV for flutterz but the stock computer did not like it one bit... sure it sounded great but i lost all midrange and the car just felt sluggish overall. It ran mega rich and was popping flames on every gear change.... as much as i hate the average pshhhhhh... i much prefer having full power ... get a PFC or the like and go for your life all good then

[gtrkiet]

your car shouldnt run mega rich without a bov??? i think it was something else? =/

[Cubes]

I've ran mine since I can remember with a blocked off BOV.

With the ceramic turbo running 1bar I covered around 100,000km's on the rb20det, then pulled it out for the rb30det. Still in good nick. I went a VG30 which was good for another 50,000km's and was still fine when I pulled that off, the Garrett gt30 I now run still doesn't use a BOV.

The GT30r has covered around 40,000km's now. Damn time flies. :S

The bov is there for emission reasons. Without a bov look what it does to your afr's on and afm voltage as you come off the throttle which causes stalling, back fires and some times flamage. Another issues is the strain it puts on your joiners/clamps. I had to replace some with t-bolts.

The reason I went no bov is the stocker was for the part throttle drivability. No bov you grab the next gear and boost is just there. Without a bov it felt laggier on gear changes as I presume it takes longer to fill the FMIC and piping than it does to regain the 'slight' speed the compressor may loose due to pushing against a pressure source.

Shaun/Boostworx runs track cars with no bov, no issues related to no bov. I know of multiple high powered RB30et's without issues running no bov.

[_K1NGTR_]

yea should be fine i did it on my GT-R and didn't have problems but it did nothing what so ever! which pissed me off because i hate my HKS SSQ BOV's !!!

[CRoNic...]

Flutter from blocked BOV = compresser wheel in the turbo suddenly spinning backwards and the sound comes through the pod filter.

Turbo's don't like this. This will cause damage in the long run. Mate has blown 3 turbo's because he blocked up his BOV over a period of 2 years and running larger amounts of boost.

I wouldn't risk my turbo for a flutter sound.

[Madaz]

Flutter from blocked BOV = compresser wheel in the turbo suddenly spinning backwards and the sound comes through the pod filter.

do you actually understand the rubbish your trying to tell people the wheels in a turbo at full boost when changing gears will be spinning around the 150,000 rpm mark there not all of a sudden going to just spin backwards

[Damo_R34]

correct Stevie, the air returning back through and slowing down the compressor and "chopping" the ait is what makes the vutututututu sound. Depending on pod filter design, it will be quiet or loud.

[Krishy]

and if you want a flutter you can get an aftermarket one and tighten it

Tightening the spring rate on the aftermarket BOV will do the same as blocking off a stock BOV

so for example your running 10psi

and the spring on the BOV is the hardest/tightest as it will go

then you go for a spin

from one gear to another you only hit 7psi

now the 7psi wont be enough pressure to lift the spring in the BOV so it will do what a blocked off stock BOV does and flutter

I had a GFB Stealth FX on my car and it did exactly the same thing

The reverse flow back across the turbo acts on the compressor wheel and causes the turbine shaft to reduce in speed quicker than it would naturally. When the throttle is opened again, the turbo will have to make up for lost momentum and will take longer to achieve the required speed, as turbo speed is proportional to boost/volume flow. (This is known as Turbo Lag) In order to prevent this from happening, a valve is fitted between the turbo and inlet which vents off the excess air pressure. These are known as an anti-surge, bypass, blow-off (BOV) or dump valve. They are normally operated by engine vacuum.

but a bov releases all the air. with no bov, the air between the turbo and throttle body gradually escapes back out the intake system. during gear change or whatever, theres still boost in the intake pipes/cooler, so it wont need to spool up all over again.

I have not encountered any drivability issues since i blocked off my stock BOV Chad

if anything i would say that boost comes a little bit quicker and earlier

so i have not lost anything but gained by blocking off my BOV

does blocking off your blow off valve affect drivability ? i.e stalling, idling problems etc

I have encountered no problems with doing that mate

no stalling or idling problems

and it also hasnt changed anything like my AFR's

Chad, Pete and Luke saw my car on the dyno last saturday at the PGA dyno thingy

and according to them and the dyno result my car sounded and ran fine

[Krishy]

damn double post

Edited October 20, 2008 by Krishy

[KISIN]

but a bov releases all the air. with no bov, the air between the turbo and throttle body gradually escapes back out the intake system. during gear change or whatever, theres still boost in the intake pipes/cooler, so it wont need to spool up all over again.

and before someone goes emo and cuts themselves saying it damages ur turbo. turbos are very robust. they handle high boost pressure and extreme heat for 100,000+kms (average life of a turbo). so releasing the air back out the intake system 'a little slower' is going to do f**k all to a turbo.

+1

[Damo_R34]

am i right in saying that increasing the boost will decrease the life of the turbo?

[Krishy]

am i right in saying that increasing the boost will decrease the life of the turbo?

if you boosted your turbo from standard boost of 7 psi to 10psi

on a healthy stock turbo this wont do any harm

and i doubt if it even decreases the life of the turbo

at the end of the day "boost is only a measure of restriction"

[AFTDRK]

[CRoNic...]

do you actually understand the rubbish your trying to tell people the wheels in a turbo at full boost when changing gears will be spinning around the 150,000 rpm mark there not all of a sudden going to just spin backwards

Just passing on what I hear/read. There's xxxx amount of topics on this subject across many forums. Everyone has different answers to it.

It's just like how some people say 98 octane petrol is the same as 95 octane petrol (which is rubbish) but people still say it.

[CRoNic...]

if you boosted your turbo from standard boost of 7 psi to 10psi

on a healthy stock turbo this wont do any harm

and i doubt if it even decreases the life of the turbo

at the end of the day "boost is only a measure of restriction"

But what if you increased the standard boost on stock ceramic turbo's?

[Krishy]

Just passing on what I hear/read. There's xxxx amount of topics on this subject across many forums. Everyone has different answers to it.

It's just like how some people say 98 octane petrol is the same as 95 octane petrol (which is rubbish) but people still say it.

who in their right mind would say 98 is the same as 95

it is now logically correct

i am not having a dig at you CroNic

but just saying that its not logically correct