Blanked Bov

[RBish]

i have a rb20det running 0.6bar, stock turbo, intercooler, bov. i thought it was set up to vent to atmosphere. untill

today i pulled the bov off to find a blanking plate. so would this be forcing the excess boost back throught the compressor wheel? and what sort of damage would this do at 0.6bar?

i pulled the blanking plate off cleaned the bov up and blakmaxxed it back on. found boost comes on alot smoother now, but just doesnt feel as snappy and generally feels weaker. when i pulled into the drive way the car started to hunt for idle crazy like 200-2000rpm? when it was blanked it was hunting around 800-1000rpm. rarely* perhaps air is getting in throught the valve causing it to hunt???

with it blocked it had that flutter sound & wasnt a bad flutter

with it vent to atmosphere it has the pssshhhhh sound.

i have a hks sqv bov,that replaces the intercooler piping to the throttlebody, so to install this i would need to blank the stock valve anyway or buy some inther cooler piping to swap for the oem pipe and that takes it out of the situation.

what would be the best option? i find it more fun to drive with it blocked i just dont want my turbo to explode.... what do you guys think would be the best option?

thanks

[045HOW]

Will be fine blanked on that boost. bov may have a boost leak which is possibly why it was banked. vent to atmo f**k with the afm unless you have aftermarket ecu so yeah changing gears fast is much smoother with it blanked and if there is a leak that is why boost seems weaker.

[RBish]

how much boost can you run safely through a blocked valve?

i am going to block it off tomorrow so i can run the hks valve and see how that goes...

once i have my fmic the stock valve/piping will not be needed

perhaps now that its venting to atmosphere is the reason why its hunting so agressively or maybe its a leaky valve...

thanks

[045HOW]

how much boost can you run safely through a blocked valve?

i am going to block it off tomorrow so i can run the hks valve and see how that goes...

once i have my fmic the stock valve/piping will not be needed

perhaps now that its venting to atmosphere is the reason why its hunting so agressively or maybe its a leaky valve...

thanks

I've been told under 300hp is fine.

If hks ssqv is the squeaky bird whistle im thinking of,don't use it blegh.

It will be leak in valve and not the fact its atmo. because its not open on idle.

[RBish]

I've been told under 300hp is fine.

If hks ssqv is the squeaky bird whistle im thinking of,don't use it blegh.

nah its a lil sneaky one i imported from japan

It will be leak in valve and not the fact its atmo. because its not open on idle.

yeah true

[krzysiu]

I ran 380hp on a blocked valve. The thing that affects the valve is pressure. Not hp value. I removed the blocking plate because when I take my foot off the accerator (running 18psi) it caused too much pressure and popped my cooler pipes off.

[RBish]

yeah i was asking how much boost pressure you can run through a blocked valve.

[TiTAN]

use a bov or dont use a bov. its up to you and its not that big of a deal and most definitely not at 0.6 bar.

[RBish]

use a bov or dont use a bov. its up to you and its not that big of a deal and most definitely not at 0.6 bar.

as i find problems with my car i want to understand whats going. not just run one or dont... once ive got my trade certificate i want to move into tuning cars so every little piece of info counts

[045HOW]

as i find problems with my car i want to understand whats going. not just run one or dont... once ive got my trade certificate i want to move into tuning cars so every little piece of info counts

Its simple. boost leak in bov. no working bov has anything to do with idle.

[Luke_GTS-T]

dw bov

[SargeRX8]

You've got air recirculating and hitting your AFM causing your car to overfuel giving you the hunting issues when you clutch in off boost or between gears. Only way to fix this is get it tuned and tweaked out if you have a programmable ECU.

No BOV are the best as long as your tune is right. I'm a fan for flutter.

[boostn0199]

You can run whatever boost you want with a blocked one

Theres no restriction. I dont belive no bov has signifant effect or if any on turbo life espcially on aftermarket steel blade turbos. Ive always run blocked for years on 18 psi no problems but its personal preferance.

[GTSBoy]

The BOV as installed on RB engines is not really intended as a BOV in the classical wanker psssht! sense. It is a compressor bypass. It is open when there is vacuum in the plenum (ie, below the boost threshold of the turbo) and it allows air to go from the AFM to the engine without having to be pushed through the compressor. This unloads the turbo and allows it to spool faster. It's pretty simple really. It probably ends up smoothing the transition to boost out a bit too (which would be a big drivability plus for an OEM like Nissan) because the BOV will only close down as the boost is coming on, so some of the boost pressure will end up recirculating for a brief time until it does shut. This would be pure speculation on my part, but it would fit in with the anecdotal evidence of people's claims of how the cars drive between having the BOV there and having it deactivated or removed. Of course it does also release extra pressure when you throttle off and may well do all the things that people claim BOVs do (improved return to boost after gearchanges and reducing wear on the turbo) - or it may not, depending on the beliefs of the user.

[Hanaldo]

Wow, so much misinformation in this thread.

[Rolls]

stock bov, aftermarket bov, no bov are all safe however venting to atmosphere or running no bov will cause it to run rich on changes and may cause stalling issues.

Personally I would run stock recirc, doesn't sound gay, makes tuning easier, no stalling or running rich on gear change issues due to not messing with the MAF, it also leaks on idle and vac which can help turbo spool.

[Room42]

no turbo = no bov. turbo = bov.

[RBish]

Its simple. boost leak in bov. no working bov has anything to do with idle.

i dont think the valve is leaking as it holds boost.

You've got air recirculating and hitting your AFM causing your car to overfuel giving you the hunting issues when you clutch in off boost or between gears. Only way to fix this is get it tuned and tweaked out if you have a programmable ECU.

No BOV are the best as long as your tune is right. I'm a fan for flutter.

i dont see how air is recirculating and passing the afm? VTA ~ it has an agressive hunt, blocked ~ idled at 900rpm.

yeah flutter is so much nicer

The BOV as installed on RB engines is not really intended as a BOV in the classical wanker psssht! sense. It is a compressor bypass. It is open when there is vacuum in the plenum (ie, below the boost threshold of the turbo) and it allows air to go from the AFM to the engine without having to be pushed through the compressor. This unloads the turbo and allows it to spool faster. It's pretty simple really. It probably ends up smoothing the transition to boost out a bit too (which would be a big drivability plus for an OEM like Nissan) because the BOV will only close down as the boost is coming on, so some of the boost pressure will end up recirculating for a brief time until it does shut. This would be pure speculation on my part, but it would fit in with the anecdotal evidence of people's claims of how the cars drive between having the BOV there and having it deactivated or removed. Of course it does also release extra pressure when you throttle off and may well do all the things that people claim BOVs do (improved return to boost after gearchanges and reducing wear on the turbo) - or it may not, depending on the beliefs of the user.

i always thought a recirc setup would help with spool. i actually wish i had hooked the recirc pipeup before i blanked it again.

stock bov, aftermarket bov, no bov are all safe however venting to atmosphere or running no bov will cause it to run rich on changes and may cause stalling issues.

Personally I would run stock recirc, doesn't sound gay, makes tuning easier, no stalling or running rich on gear change issues due to not messing with the MAF, it also leaks on idle and vac which can help turbo spool.

with it blocked no hunt, with it VTA aggressive hunt... ?

Wow, so much misinformation in this thread.

enlighten us all.