Question about BoV on RB25DET NEO

[Kapr]

Hi. Iam just curisou about this topic.
I saw this video.
It is about Greddy Type FV2.
I know that BoVs are about that sound but how and when to use it?
I read some topic here and from what i have understand on stock RB with MAF there will be some "problems" if you use this BoV?
It vents the air in to the atmosphere and the MAF on stock car needs this air back in to the intake and not out? Or is it wrong?
If so...i saw you can put some adaptor to circule air back...but does that not "loose" that sound?

I saw another BoV from Turbosmart and it has two "exhaust" like ports? One is for the stock tubing for letting air back and one is for "sound" and let the air in the atmosphere?

Can someone please explain?
This is the Greddy one: 

And this is the Turbosmart.

 

 

THANK YOU!!

EDIT:
So i read about this topic some more and i if i understand that correctly:
That Greddy can function either like BoV or 100% Bypass valve?

And that Turbosmart is what they called hybrid so you can adjust what and how many air can be vented out or back in?

Is this right?

THX!

Edited April 5 by Kapr

[Murray_Calavera]

You've just discovered a really good reason to tell yourself, yes, I do need to buy an aftermarket ECU.

Put the MAF in the bin. Slap in the new ECU and have a think about what turbo sounds you prefer. 

Do you want a 90's style BOV wooosh?

Do you want a hektik tsututututu? 

Mate, can't go wrong. Just gotta get that ECU and the world is your oyster. 

[Dose Pipe Sutututu]

Want that BOV to work properly? Pair of with a Haltech and a bunch of sensors.

Modernisation, better fuel economy too.

[Kapr]

Ok thanks guys that is what i thought and learned from all the comments/videos too.

If i want to BoV i need/want to have standalone ECU 🙂

And the bypass valve tge car has is good for stock(little bit more) power.

[GTSBoy]

Stock bypass valves are good for plenty of boost.

[Kapr]

Yeah i know(now)
I just wanted to ask.
It maybe looks like i get my hands on RB25DET NEO for swap 🙂 

[Kapr]

Hi...a little refresh.

Is Nistune gonna be enough to run BoV? Or do i need some proper ECU? 

[joshuaho96]

4 hours ago, Kapr said:

Hi...a little refresh.

Is Nistune gonna be enough to run BoV? Or do i need some proper ECU? 

Atmospheric vent requires something that doesn't use a MAF for load. You would need a standalone ECU for that.

[Kapr]

Yeah i know that MAF is no no for this type of BoV.

The engine has no BoV and "hose/pipes" ..it was all deleted (or probably it was not even on the engine when it was bought  )
It does that "sutututu" noise which i kinda do not want(atmospheric is better IMO...but standalone ECU) 

What are the cons of running without blow off on stock RB25DET NEO. It running 5-7 PSI max (it has boost controller)

 

EDIT: and can Nistune be "tuned" to know there is no BoV to i dont know "know" and be better for a car?
I read so many info about no BoV.
One guy saying it is bad and hurting the turbo/engine/car and other that it does not...
 

Edited Thursday at 11:48 AM by Kapr

[Dose Pipe Sutututu]

A work around is to install the R35 card style AFM/MAF on the cold side of the intercooler piping and the BOV on the hot side piping.

Works well, also you can combat the revs dropping by adding a bit more ignition timing on the idle ignition timing table to slow the rate of RPM drop.

[Kapr]

So i just change the (whatever is inside ma original MAF and slide the R34 MAF (it is gonna fit right in? ) and somewhere on the hot side a BoV...i presume that would be vented to the atmo?

I just "trying" to understand...maybe my mechanic would know this  

I would not mind(even prefer) to run stock BoV cuz it is way more than fine but i do not have that and only pipeing what is left is oem J pipe ...
I will be running Blitz fmic(to fit oem one side style) and i gonna need custom pipes cuz i do not have rest of those pipes and hoses...

But i am want standalone ECU. Only choice i have atm is Nistune...but that is not gonna cut it right?I dont know what Nistune can and cant do...
I know you guys know Link and Haltech...but whatabout ECUmaster? I know guys in here run those but i literally do not know about that and do not know differences...
Just know to take whatever "my" tuner can work on.
 

Edited Thursday at 07:28 PM by Kapr

[joshuaho96]

8 hours ago, Kapr said:

Yeah i know that MAF is no no for this type of BoV.

The engine has no BoV and "hose/pipes" ..it was all deleted (or probably it was not even on the engine when it was bought  )
It does that "sutututu" noise which i kinda do not want(atmospheric is better IMO...but standalone ECU) 

What are the cons of running without blow off on stock RB25DET NEO. It running 5-7 PSI max (it has boost controller)

 

EDIT: and can Nistune be "tuned" to know there is no BoV to i dont know "know" and be better for a car?
I read so many info about no BoV.
One guy saying it is bad and hurting the turbo/engine/car and other that it does not...
 

Even with no BOV you will have issues unless the MAF is a hot film type like the R35 which has some design features to deal with reversion. Hot wire MAFs are very sensitive.

[Kapr]

What issues are those? Previous owner said it wants to stall sometimes. We did test drive and it was nice and smooth so it will be sporadic or idk.

And if i just change MAF(the sensor to R35 version) it should be better? And as i asked...is it like "plug n play" with oem MAF from R34? 

This is a MAF from R35 right?

[joshuaho96]

18 minutes ago, Kapr said:

What issues are those? Previous owner said it wants to stall sometimes. We did test drive and it was nice and smooth so it will be sporadic or idk.

And if i just change MAF(the sensor to R35 version) it should be better? And as i asked...is it like "plug n play" with oem MAF from R34? 

This is a MAF from R35 right?

Pinout is different to my knowledge, but you should confirm to be sure. Also you will need to adjust the VQ table in Nistune to suit. I would still recommend sticking with recirculating BOVs, I'm not sure if the R35 card MAF will fully resolve stalling caused by reversion/throttle lift.

Edited Thursday at 08:44 PM by joshuaho96

[GTSBoy]

It's not as simple as it is being made out to be. It's not hard, but there are things that have to be done.

Am busy right now, but will try to essay later.

[GTSBoy]

Essay time.

First things first, an RB running stock turbo and boost levels shouldn't get so bad as to stall from reversion if the recirc valve has been deleted. Should get a little fluffy and annoying, but in my experience, not so bad as to stall. Of course, every car is a bit different, so it remains possible that stalling will happen.

So, running with no recirc valve is somewhat of an option, for otherwise stock stuff.

Atmo BOVs cause all sorts of shit, even on an otherwise stock setup. Only gets worse the higher the boost and the bigger the turbo. At that point you really need to go for a different ECU and no AFM.

Rebuilding the stock recirc valve configuration is not hard. You just need a stock or aftermarket BOV with the appropriate adapter for the 2 bolt flange on the back of the J pipe, and to get/make an appropriate ~1" pipe to get the air back to the turbo inlet, and to possibly modify the inlet (if it is not stock) to take the recirc pipe back in. Not hard. Just takes some cutting and welding.

Putting an R35 type AFM into the car anywhere is not as simple as just buying the AFM and throwing it in. You will also need to buy the appropriate boss that will then need to be welded onto the pipe where you're installing it. You can clearly see why by looking at the photo posted above. They are not a "simple" swap for a stocker. You can't put on in place of the stock AFM.

You can put one in place of the stock AFM, if you get the mounting boss and weld it to some pipe and otherwise make that pipe piece work like the stock AFM housing. Or you can buy such an adapter, either complete with the 4 bolt flange for the air box, or without, for varying degrees of work needed to then make it fit your stock airbox or some pod filter or whatever you have going on.

Oh, and the R35 AFM is not plug and play. The wiring is different, but changing that is trivial. The plug is also different so you either end up repinning the original wires onto the new plug, or you just use a short adapter.

If you weld a boss to the cold side pipe, the cold side pipe really wants to be 3", otherwise the scaling on the meter can get a bit weird, but whatever the pipe size, it's not as easy as just using the (fully documented in the Nistune doco) simple method for choosing R35 AFM in X" pipe size in the software, because the scaling will already be a bit different. Anyway, all of this has been comprehensively worked through on the Nistune forums, so there is full knowledge available.

I would use a Link/Haltech before I would bother putting an AFM into a cold side pipe. That's a lot of effort for a bodge.

Nistune is great, can work well even at fairly high power levels, but you are stuck with the limitations of it being the stock ECU, which includes needing to use an AFM, which is not always convenient for every set of modifications. You have to have a think about what you already have, what you want to have, and decide early if you'd be better off jumping ship to an aftermarket ECU. This so you don't waste time and money doing things 2 or 3 times.

Never heard of ECUmaster. Sounds like a backyard operation. If there are good tuners for it where you are, and it is a solid product, then it will be fine. We're only talking about an R engine here. Back in the day they all ran on crude nasty early 90s ECUs and they were fine. You don't need a rocket surgeon's ECU to run one.

[MBS206]

3 hours ago, GTSBoy said:

 

Never heard of ECUmaster. Sounds like a backyard operation. If there are good tuners for it where you are, and it is a solid product, then it will be fine. We're only talking about an R engine here. Back in the day they all ran on crude nasty early 90s ECUs and they were fine. You don't need a rocket surgeon's ECU to run one.

ECUMaster is an Australian company from memory, been around a while, and seem to actually play really well on more unique engine setups. Seems to be more of them being used in the states, and they seem to support more cylinders than most others.

 

My opinion on stock ECU/Nistune with he AFM, is you can tune around the issue of stalling. It's still a bit of a band-aid, and not the most perfect smoothest setup, but it can make it drive able and not an absolute PITA. But you're still compromising.

A vent to atmosphere BOV has the same issue as no BOV with regards to the AFM. Both make the ECU think more air is entering the engine than there really is.

And I can't find any hard science/decent evidence that supports the claims all the "you MUST run a BOV of some sort of you'll blow the turbo up".

About the only one some people can give of why is "lag between gear shifts", and that is only an issue when your boost source for the waste gate is pre throttle body. I ran my boost source for the TD07S off the inlet manifold. Didn't have weird boost spiking issues, didn't have boost control issues, and on a gear shift the wastegate slammed shut, which meant all exhaust gases would be keeping it going round and round and not waiting for the wastegate to shut again when I stepped off the clutch and back on the loud pedal. It came back on boost in the next gear pretty much instantly.

 

ECU / tune / BOV choice I think really comes down to a lot more factors than just what you've stated. And personally, especially for daily driving, recirc setup for the BOV, or no BOV. I dislike the really loud BOV when everyone is taking off from the lights etc.

[Yeetus]

Well the good news is that it won't run any worse with an atmo bov than it does with no bov, I've owned a few Nissans over the years (r32, s15 and now r33), the stalling issue caused by a bov or no bov while still having an afm is easy enough to live with, most people get used to driving them and just feathering the throttle when you come to a stop to avoid it stalling.

Changing to a proper ecu with a map sensor is ideal but in the short term I'd just slap in the bov if you really want the whoosh sound.

I looked into the pass through type maf like the R35 one above but decided against it as the amount of oil and crap flowing through the hot side would mean you'd have to clean it often to keep it working.

[Dose Pipe Sutututu]

Here's the workaround with Nistune I was talking about, just add in more timing on the decel table

And play around with the fuel cut & recovery, it's enough to stop it from stalling on a decel

 

[Kapr]

Wow guys thank you very much for the HUGE info :-)

@GTSBoy
I have like 30 minutes if test drive with that car/engine and it not stalled once. IMO it ran very smooth so i guess it was not that bad(but asi i said it is stock)
That atmo BoV is worse than no BoV or in my case or it is/will be the same? Cuz frankly i rather have little whooosh sound than that sututu 😄
But either way the less harmfull for engine/turbo the better(if the stock is not an option right away)
Yeah about that rebuild i talk with guy who will be doing swap and custom pipes...i think i can get stock BoV or get aftermarket which will function the same.
Yeah i looked at that R35 option and i try ask my mechanic more about that if he knows.
The engine has stock ECU but i can get Nistune for it. On that stock it runs quite well...but i have limited time with it so rly dont know.
Ecumaster is this https://www.ecumaster.com/ 
It is not some dodgy backyard ECU :-) 

@MBS206
Yeah but it will be better to have Nistune than the completely stock ECU no?
About that "same" atmo/no BoV.
The drivebility would be the same? I dont know but i kinda guess that amto BoV would cause more problems than no BoV in my case? Or is the same? You just "change" one sound for the other?
Yeah i read many many many topic about hurting the turbo. But no one know anybody that would 100% tell that his turbo/engine blows/get damaged by not running BoV.
Of course turbo would be little happier IMO if it has BoV ..but if you do not trash i think i should be good. And as you can see iam already trying to get this right...just working what i have right now :-)

Yeah iam kinda the same...i dont want nothing loud and frankly iam not liking that sututu noise that much 😄 i rather have little bit of "whooosh" or no sound at all.

Of course in my case it si a completely another world when you came tu Turbo car with open air box and no BoV and you driving the N/A ...all i hear is engine. Here? I heard turbo/sucking and that sututu 😄

@Yeetus
So in my case it is really no difference to run no BoV or some atmo BoV like GReddy FV2? The car would drive the same and has "the same" little problems? As i wrote above i kinda thinked that atmo BoV with stock MAF would cause more problems...but then again i dont know much about no BoV either :-) 
So to avoid stalling i "cant" just put neutral on stop lights like from higher rpm? Or?
Yeah iam already looking for ECU :-) 
Yes iam at the same side with thar R35 MAF :-) 

@Dose Pipe Sutututu
Thank you i (my mechanic/tuner) will look into that) Guess iam taking the Nistune at least :-)