Jump to content
SAU Community

Recommended Posts

hi guys

i was just wonderin whether or not with the stock BOV on the R33 you can pull the plumb back hose off and make it atmospheric. does this cause any problems??? and does it work better, not better, works the same, just makes a louder noise. what?? can u please email me to tell me, thanks alot.

email is: [email protected]

Link to comment
https://www.sau.com.au/forums/topic/39036-stock-r33-bov/
Share on other sites

Godfather - I'm guessing the stalling is for two reasons -

1. runs rich because AFM will read higher than actual air into engine when BOV vents;

2. stock BOV leaks on boost (see thread titled "BOV mod" or something similar...) causing excessively rich.

I have a rice-boy-spec vent to atmosphere - It idles OK, stalls about once a week - After market management will fix that.

lbfalcon - don't know what you are talking about mate... you will not shatter your turbo because there is no airflow back to the turbo. I think you have confused having no BOV, the air feeding back to the turbo through the compressor will have long term damaging effects on the blades and bearings.

Link to comment
https://www.sau.com.au/forums/topic/39036-stock-r33-bov/#findComment-792405
Share on other sites

the stock bov does not leak on boost, it leaks a tiny little bit of air around 0 pressure to make the transition on and off boost smoother.

The BOV mod is nothing special it does nothing for power. I tried it and I must say leaving it alone is the best idea.

Link to comment
https://www.sau.com.au/forums/topic/39036-stock-r33-bov/#findComment-793141
Share on other sites

Ronin - i think i know what ure referring too... seems familiar.. something abt placing a small screw on one of the small holes at the bottom of the bov.. will look it up
Don't use a screw, use the little black lid bit out of the top of an old style BIC Biro. Does the same job, fits the hole like it's made for it, and can be removed without having buggered up the OEM BOV :D
Link to comment
https://www.sau.com.au/forums/topic/39036-stock-r33-bov/#findComment-795152
Share on other sites

I wonder if a stock bov with the screw mod vented to atmo would idle better seeing as it wouldnt be leaking and causing afr probs?? Just a thaught..

I know a completly stock one will contiuously stall when vented to atmo.

My stokies got the little mod might vent it to atmo and see how it goes just for curiositys sake, however i dont know why youde want it venting to atmo considering all the negative sides to it, and if your into the noise the stockie bov plumbed is pretty loud when youve got a pod filter, well mine is anyway.

Link to comment
https://www.sau.com.au/forums/topic/39036-stock-r33-bov/#findComment-796593
Share on other sites

I wonder if a stock bov with the screw mod vented to atmo would idle better seeing as it wouldnt be leaking and causing afr probs?? Just a thaught..
In my case it made my idle rougher and caused minor surges, but this was plumbed back...

I originally had an older style Turbosmart Type II BOV which caused a rough idle and surging.

I went back to the factory BOV and the rough idle and surging went away completely, however as already mentioned it just wasnt as snappy.

So I did the screw mod, there was a noticable difference, but it idled a little rough and was surging again but not as bad.

Link to comment
https://www.sau.com.au/forums/topic/39036-stock-r33-bov/#findComment-797077
Share on other sites

the screw won't help your cause with it venting to atmo, that little hole just does exactly what rev210 says, smoothes out the transition from off-on boost. blocking it just stops that from smoothing out.

Ok, wouldn't that little leak be just like if you had a leak in your manifold (when the stock bov is venting to atmo of course) and a leak in your manifold would cause rough/no ide wouldn't it?

I just recon this little leak is why the stock bov doesnt idle when vented to atmo and most other aftermarket ones do because they dont have that little leak.

Dont get me wrong im all for the stockie being plumbed back and dont know why anyone would want it venting to atmo. My mate tried to tell me once that venting to atmo was better cause the hot already compressed air went back infront of the turbo again with a plumb back, i dont recon this is really true cause when air drops in pressure it drops in temp aswell so theoretically it would go back at the same temp as it came in, accept of course that the intercooler has already taken some heat out so maybe the air would go back at a lower temp than it came in? would this make plumbacks better??

Also i can see some good in blocking off the hole, yes it may stop the smoothing out as may people have said thats why nissan put it there but surly the turbo would not be working as hard to make the same boost?

Link to comment
https://www.sau.com.au/forums/topic/39036-stock-r33-bov/#findComment-797227
Share on other sites

the stock bov does not leak on boost, it leaks a tiny little bit of air around 0 pressure to make the transition on and off boost smoother.

The BOV mod is nothing special it does nothing for power. I tried it and I must say leaving it alone is the best idea.

How does air leak at zero pressure?? i always thaught you needed a difference in pressure to get movment. anyhow i know for a fact it does leak under pressure cause i blew on it and like alot of other peolpe found out when they tried this it bypassed air (leaked), aparrently a human being can generate almost 2 psi with there mouth i found the harder i blew the more it leaked. this would mean it leaks under pressure wouldnt it?

Link to comment
https://www.sau.com.au/forums/topic/39036-stock-r33-bov/#findComment-797278
Share on other sites

  • 1 month later...

I can say that yes the stock bov vents on spool when I had it venting to atmosphere, I rigged up a really dodgy bent piece of metal which then bent out to vent the air, but I found that having something blocking it almost stopped the stalling on idle, I found this out by holding my hand over where the air vents and it idled smooth as silk, once I unblocked it, BAM rough idle?

I have no friggin idea what this means and am not a mechanic, I will be taking pics later on before I reattach the plumb back just to prove how DODGY it was :(, sick of just before boost hearing a constant whoosh from the bov and thinking of all that power being lost :D

Link to comment
https://www.sau.com.au/forums/topic/39036-stock-r33-bov/#findComment-886353
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • @666DAN sorry to bring you and old thread.     I've got my de+t done and it's all running great other than 1 small issue.    Car has remained auto with the na auto and tcm, I've used a stagea ecu with. NIstune board and everything is great other than my gear selection on the dash. It illuminates park, reverse, neutral, 3rd and 2nd when selected . But nothing when in  drive or what gear your in when you pop it into tiptronic. I'm sure there is maybe 1 wire in the ecu plug I need to move to rectify this. Do ya have any ideas?     Cheers man
    • Well I recently changed my rear axles and was thinking if I bumped anything, I have been driving the car for a while now though... But it has been raining today so everything is wet under the wheel arches. Brakes feel fine and can't hear any of the metal screamers, I had a squeak coming from one of the handbrake drums but that seems to have gone away a while ago. I was going down a hill when it lit up and I did feel the abs bite for a second and question why it did it?
    • Correct. Um. I dunno. I haven't cared enough about the way that the NA cars work to know for sure. But..... The 33/34 turbo manual cars have an electronic speed sensor in the gearbox that outputs a +/- (ie, sawtooth AC) voltage signal. That is connected to the speedo. The speedo then outputs a 0-5v square wave (ie, PWM) signal that the ECU (and any other CU on the bus) sees. The speed sensor is NOT directly connected to the ECU. So here's the problem. Your new ECU expects to see the PWM signal, but must somehow be getting a direct signal from the diff speed sensor. Which would suggest that the wiring of the NA car is not the same as the turbo cars. I think you will need to spend some time with (hopefully the wiring diagram for the car) and a multimeter to see what is connected to what. Then, presuming I am correct**, you would then want to separate the ECU speed signal input from the rest of the car's wiring, and probably either buy a speed signal converter, or build one using an arduino (or similar). That would take in the speed sensor signal and output a scaled (and suitably rearranged) signal for the ECU. ** We shouldn't presume that I am correct here, because there might be something else crazy going on. I don't think you could convert the speedo to be fed from the gearbox sensor, because the pulse rate from that sensor is probably different to the diff sensor and then the speedo would read wrongly. And this also wouldn't fix the ECU's problem either, because the ECU doesn't want to see the gearbox signal direct either (assuming that they are all on the same wiring, for some odd NA related reason, see above caveat!) Does this help? Probably not. Can you make it work? Almost certainly. With the above work. You should buy a handheld oscilloscope from Aliexpress so that you can view these signals directly. Connect up the probes and drive the car. Show photos of the screen when drving at known speeds and connected to different places, and we'll see what we can learn about it.
    • Assuming your brake pads are not worn right down, I'd add a little brake fluid. Is there any sign of a brake fluid leak?
    • Hello all,  I need of some help. On my drive home my handbrake light lit up and started flashing. When I got home I checked my handbrake sensor under the centre console and nothing seemed out of the ordinary. I have scanned my car via the consult port, no codes shown. Checked my brake fluid as well which is half full. Tried unplugging the brake master but it didn't change anything. Thoughts on what it could be? The master float doesn't seem to be stuck. My car is an 1998 ER34 sedan GT. No hicas but has ABS Photos below 👇🏾 
×
×
  • Create New...