BOV placement questions....

[rn240sx]

Well, when i was running my 370cc inj with stock maf, i had my bov mounted on the hot pipe and it was blowing to atmosphere.... ZERO idle problems, and ZERO stalling problems...!!

I then went to the 555cc inj with z32 maf and moved the bov from the hot pipe to the cold pipe and mounted it just b4 the throttle plate. I then started having stalling problems and idle issues. That is until i recirculated the bov and removed the INNER spring of the bov so that it will act as a compressor bypass so that the IACV can breathe and maintain good idle upon shifts.. Thats when my idle was perfect and NO stalling out... My problems were gone it drove as if it was n/a

Does it really matter where the bov is mounted or what..?? Can i put the bov back on the hot pipe and leave it vented to atmosphere.. or will it start up my idle issue's again..??

Obviously it doesnt need to be recirculated cause i had it vented to atmosphere with my 1st setup and it ran fine, it was only till i moved the bov to the cold pipe and upgraded my fuel system when my problems started and the only fix was to recir it and modify the bov to be used as a compressor bypass to let the iacv breathe...

Any comments..??

[JRL]

From what Ive read the BOV should be placed with in 15" to 12" from the throtlle body.

[hannibal]

Using a blow thru setup, right? Is your BOV before the MAF??

[rn240sx]

So what ur saying is that if the bov is mounted 12-15 inches b4 the throttle, that should alow me to run open bov without it effecting my idle during shifts..??

My initial setup was the bov on the hot pipe... but that was with a smaller fuel system if that even matters...

[Craving4Boost]

what's your fuel management?

[nissanfanatic]

Closest to the TB is best as that is where the pressure wave begins. IDK about the stalling issue, but I don't have any stalling issues with mine right there. I am recirculated.

Open BOV is really a toss up if its gonna work. I had mine open for a little bit. Some days it would idle just fine. Then out of the blue it would begin acting up. There really is no telling if its gonna work or not.

[JRL]

So what ur saying is that if the bov is mounted 12-15 inches b4 the throttle, that should alow me to run open bov without it effecting my idle during shifts?

Nope. Having the BOV located on the cold pipe is still MAF measured air. Which means when its blown off you will/can have the potential to stall. And what Nissanfanatic said was right.

The only way to run an open air BOV on our cars is to have an Anti-Stall feature on whatever engine management your using. E-manage has this option. Im not sure if JWT does.

[ILikeMy240sx]

Does anyone know if Enthalpy has the anti-stall feature?

[nissanfanatic]

Or run a MAP air metering system.

[JRL]

Or run a MAP air metering system.

Which requires a full stand alone system, or, E-Manage.

Something I forgot about would be to use a blow through MAF set up. You can run an open air BOV this way, but, then the BOV placement becomes a little cramped if you still wanted it on the cold pipe.

[virus77]

Even thought the emanage has the option to tune based on map it doesnt work like a standalone. It still requires the MAFS to work, also the anti-stall feature on the emanage is a MAFS based system that clamps the MAFS voltage so it is not really map based at all when it comes to anit-stall.

[nissanfanatic]

I was just throwing all the options out there.

I wonder how a HKS Vein Pressure Converter(VPC) would work on a KA...

[Fulcrum]

Too bad HKS doesn't make em any more. Maybe someone will start making something like it. It shouldn't be too hard. AFAIK it's just a MAP sensor that scales the voltage to mimic the MAFS.

[nissanfanatic]

Yea, you can still find people selling them though. ebay and such.

[DRIFTEADOR]

Closest to the TB is best as that is where the pressure wave begins. IDK about the stalling issue, but I don't have any stalling issues with mine right there. I am recirculated.

where'd you find that?

that's what most think, until recently including myself, but where's the proof? full-race (well-known, proven shop) seems to like them mounted on the ic:

[nissanfanatic]

Wheres the proof on that? Who says it best? And not everyone has access to a welder capable of welding aluminum. Plus if you screw up really bad on a piece of steel pipe, oh well. IF you screw up an intercooler. Dammit, out a couple hundred bucks. Not to mention, that doesn't look like a very optimal spot for recirculation.

IDK if anybody really knows where the best place to mount it is. But I know that I have no compressor surge with it mounted close to my TB. So it works the best for me. When I had it mounted closer to the turbo, even with the bottom port hooked up, I had compressor surge. So I'll just use this way.

To each his own.

[DRIFTEADOR]

i guess the proof would be their high hp cars running that setup. I'll go ahead and e-mail them about it. I don't think everyone should go weld their bov's to their endtank because thats the best spot but maybe it just doesn't matter as long as i'ts between the compressor and the throttle plate.

[nissanfanatic]

I will go as far to say that it probably doesn't make that much of a difference where its postitioned.

[D Money]

i was planning on putting it on the hotpipe, seems like it would let the intercooler stay colder

[DRIFTEADOR]

http://honda-tech.com/zerothread?id=333587&page=1their explanation for whoever cares to read through 3 pages. basically, no one ever went through with the test and its still up for debate....although no one really cares cause the difference woulnt be so great to choose one over the other

[Jookmasta]

have mine mounted on the hot pipe. no decel settings set on the safc and i have no stalling/idling issues. its a type s to the atmosphere. also no compressor surge over here

[toki]

Throttle body. Keep it close to the throttle body.

You arn't discharging the air your compressor is still flowing, you are discharging the air which has reversed itself after hitting the throttle body. If you let your whole piping system and intercooler fill up with this reverse flowing air first it will likely overwhelm the BOV initially and cause surge.

this is from experience not only from myself by many many people running 20+ psi.

[erollinc]

sooooo basicly those who have them on the cold pipe are having issues if its not recirculated..... people who are running their BOV on the hot pipe venting into the atmos. arent having problems at all?

i guess my bov is going on the hot pipe lol..... as weird as it seems to me to put it there

[ILikeMy240sx]

theoretically, regardless of the position of the BOV, if its venting the air thats already been metered then you will run rich unless of course it has been tuned correctly.

My friend has a SR and its on the hot pipe w/ SARD BOV and his idle is smoother than my N/A KA but then again he tuned his Nismo ECU himself and has alot of experience with bunch of motors.

[e_c]

please dont flame as i am not too knowlegeable when it comes to turbo things, but if you had the maf on the cold pipe, and the bov on the cold pipe, but closer to the ic, then you wouldnt have to worry about venting registered air cause it hasnt gone past the maf yet, and you would get all the benefits of having the bov on the cold pipe as some one stated above, just an idea though

[D Money]

yeah if bov was before maf it would work good, but supposedly burn out maf pretty quick

[SloMoe]

please dont flame as i am not too knowlegeable when it comes to turbo things, but if you had the maf on the cold pipe, and the bov on the cold pipe, but closer to the ic, then you wouldnt have to worry about venting registered air cause it hasnt gone past the maf yet, and you would get all the benefits of having the bov on the cold pipe as some one stated above, just an idea though

Often referred to as a "blow-through" setup. Just make sure to route the PCV back into the turbo before the compressor and not vent it to the atmosphere.

[rn240sx]

Often referred to as a "blow-through" setup. Just make sure to route the PCV back into the turbo before the compressor and not vent it to the atmosphere.

WHY IS THIS..??

[e_c]

ya.... i assumed that if the blow off valve was before the maf then the idle would be fine if vented to the atmosphere...