Blow Off Valve Question

[ClutchBurndout-:(]

hi guys, simple question, I know nothing about blow off valves but im keen on installing one, are there any out there that when released pressure give a simple psshh instead of the ghey do do do do do do do noise, I don’t want anything fancy, just something that does the job well. is there any place to buy them? i was thinking of going to autobarn but im not to keen on them, is there anywhere in vic south east? cheers

[paulr33]

hi

you are confused and getting mixed up

when you dont use a BOV or its mega tight, it doesnt function, which traps the pressure in the manifold and turbocharger compressor

the do do do do noise is the air pressure doing a mid air collision with itself and surging

when you use a bov, the pressure is vented to the front of the compressor and all is well

the purpose of a BOV is to open when pressure in the manifold spikes well past normal limits the BOV opens, and dumps this built up pressure when the throttle body closes to the front of the intake system.

the best BOV is the std unit, setup in the std method and operation

the 2nd best BOV is a single GTR BOV setup in the std method and operation

the 3rd best BOV would be a std unit

and so on

theeres no need for an aftermarket unit

if you insist on an aftermarket unit , stay away from ATMO VENTING units, that is, units that DO NOT plumb back

they will cause it to stall, act stupid and run like crap

SAY NO TO ATMO

[ClutchBurndout-:(]

oh, i thought that dododododo noise was the presure being released, ok well i know there is a stock bov on the gtst, im not sure how good they are though, is it worth looking into a new one to vent the presure quicker to prevent back presure on the turbo?

[paulr33]

nope

pointless, waste of time, waste of $ and waste of everything

the std bov is fine, is reliable, if you want to get noise from the std bov

remove the std airbox and fit a pod filter, youll hear the bov working but it wont be doo do do dod

thats compressor surge the do do do do noise

commonly associated with a vl turbo, as they dont have a factory bov

so when their throttle body closes, the pressure surges and collides mid air with itself

this in turn harms the compressor wheel as its subject to excessive pressure repeatedly

[im late]

hi guys, simple question, I know nothing about blow off valves but im keen on installing one, are there any out there that when released pressure give a simple psshh instead of the ghey do do do do do do do noise, I don’t want anything fancy, just something that does the job well. is there any place to buy them? i was thinking of going to autobarn but im not to keen on them, is there anywhere in vic south east? cheers

Hi Matt,

You car has a blow off valve standard. The reason you can't hear it is because the unused air (which creates the sound) is feed back into your intake piping to your turbo.

Unless you have an aftermarket ECU that relies on map signals rather than the standard air-flow meters then it will not be a good idea to vent to atmosphere.

If you really want the "psshh" sound then get an aftermarket pod filter (like a K&N) so that you will hear "some psshh".

You won't need to upgrade your BOV if you are going down that path.

Anyone that tells you that you can vent to atmosphere with a standard ECU + standard airflow meters does not understand the complexities of how the standard ECU works. It measures the air volume it sucks in through the intake and pushes that air through the inter cooler.

When unused air (the air that does not go into the plenum) is released through the BOV, then this air volume needs to be run back through to the airflow meters so the ECU can make correct air/fuel mixtures.

Bear in mind POD air filters and “aftermarket” BOVs may be illegal in your state.

If you really want to get an aftermarket BOV, support the Australian industry (through your stimulus donation from Rudd) and buy a Turbo smart. Turbo Smart is very popular and supplied worldwide.

Check out: http://www.turbosmartonline.com/index.php?id=46

The model you need is the “Nissan Dual Port, Part Number: TS-0205-1026”

Remember this needs to be plumed back into your standard BOV return piping for your car to drive and idle fine and for your fuel/air mixtures not to go crazy.

Hope this helps.

[JAS-25T]

oh, i thought that dododododo noise was the presure being released, ok well i know there is a stock bov on the gtst, im not sure how good they are though, is it worth looking into a new one to vent the presure quicker to prevent back presure on the turbo?

No it is not.

It wont vent any quicker, unless the spring is set at a lower pressure. And then you will be venting air before it gets into the motor, loosing manifold boost.

The standard unit works a treat and there is no reason to replace/modify or other wise it unless it has stopped performing its intended function due to a mechanical fault.

[im late]

By the way Matt,

My car is doing 445 AWHP with two standard BOVs.

No probs...

I am venting to atmosphere becasue I have a MAP sensor based ECU. I am going to plum back soon because I DON'T want attention form the boys in blue.

I wouldn't touch anthing on your car just for the sound.

Edited March 27, 2009 by im late

[ClutchBurndout-:(]

ok no worries, thanks guys, the only thing that made me ask is because apparently there is these you buet bosch bovs made for saab that are fantastic, they stop the presure from hitting the turbo which stops the turbo fan to stop spooling, which is a pain when giving it some curry and when changing gears, coming into the next gear you have to re spool the whole turbo up again. this sound right?