veyenyl

That is correct. I was thinking MAP setup but typed Z31 setup.

Try it vented and see if it works out for you. If you're happy with it leave it. I tried it on an all stock motor at 10psi with a supra IC and didn't like it. It ran much smoother recirculated. Your car may respond different with a different BOV then what I used since the 1G DSM is not known for good sealing and quick response.

snwbrderphat540

the 1G BOV isnt, BUT, you can aactually crush the tops of them and they seal GREAT! its a DSM trick. lol. and the car isnt going to run like crap, its just going to be iffy between shifts. and whats so hard to see about it stalling the engine. its under boost flowing alot fo fuel and then POOF! all the pressure is gone since the BOV goes, it doesnt have enough air and the engine stops running, put it back in gear and its back to running. now with a recirc not ALL the pressure is gone there wil be a short little surge of air just enough till the injectors click back down to the non boost flow rate.

NismoPick

Apparently reading skills own you:

In more simple words, I ALREADY did that.

snwbrderphat540

no.... a REAL DSM! the actualy car not just teh BOV on your car. the DSM as a whole. reading comprehension owns YOU! i never said go get a 1G DSM BOV.... i said go get a 1G DSM and unplug the recirc. jerk. :P

NismoPick

yeah... lemme just run out and buy a dsm (which is not a Z) and unplug the recirc leaving a nice vac leak... to prove absolutely nothing about how it will work on a Z (because again, a dsm is not a Z).

thxone

That's drizzle for shizzle my nizzle. You keep getting owned Snw...why you let him do that to ya?

lifegrddude

The Z31 setup runs like crap if you upgrade to much injectors for sure. My 440's will stall the motor if I leave the gear in D and let off suddenly at at low rpm in 2nd or 3rd gear. (~1550, the transmission shifts way too early to get to 3rd) In stop n' go, I have to leave the transmission in 1st and manually shift it to avoid stalling. At higher speeds and rpms it's not an issue though. I leave my bov vented because when I upgraded my turbocharger, I couldn't use the stock intake piping to the compressor, so I had no recirc line anymore. But like I said before, the stock efi wasn't really affected by a vented bov. I had 370's on the stock efi and never stalled once even when I tried the vented setup. The 370's on the Z31 setup was ok too, I only stalled it twice during the 8 months I was running that setup.

To answer the other general questions, I'm running 16 psi as my max, a larger fuel pump, 440cc injectors, etc. Stick driving skills have nothing to do with the motor stalling from a vented setup. If you don't mind a little compressor surge, you can tighten the bov to reduce the time it's open as well.

snwbrderphat540

i didn't get owned for crap, i made a quick anecdote to it and how it COULD POSSIBLY effect the Z, and nismo goes to from what i read arguing how a DSM (not the BOV on a Z) wouldn't do what i described. he just took it out of proportion and we misinterpreted on another all the way through. so it was just a stupid misunderstanding. we owned ourselves. don't be saying i got owned, he is equally at fault for this brew ha ha miss hap. i want apologies. lol

NismoPick

Snwy... I was just stating that we're talking about a Z, not a DSM car. I would imagine that a DSM would run poorly if you remove the recirc because it's made (and the ecu is programmed) that way from the factory.

The simple answer to this long debated out thread is that a stock 280zxt can have a vented or recirc'd bov. So pick whatever you want and go with it. Yay!

thxone

Hey Snw, you know I am always kidding....never mad at you.

Hey, I heard a car tonight when I was getting gas...oh, by the way, my 280ZXT is back on the road...and it had a BOV and it sounded really nice...looked like a Nissan of some kind....maybe a 240sx but it looked longer. I also did something to my car....here, look at the pic:

lww

Hey! Where'd your front bumper go?!

thxone

I don't know why I did it, I went out this morning to put the new Alternator on and all of the sudden I was taking the front bumper off...I never even second guessed it when I was doing it. The bumper and mounts are screwed anyway and after I got it of I finished fixing the car. I did start getting ideas for the front end once I got done with the car....we will see how it goes and I will post pics after. I think its gonna be cool though.

snwbrderphat540

i know, like i said, i mentioned it since we were on DSM's, 1G's, and BOV's being recirculated, than you said no it wont, but talking about teh 1GBOV on a Z and i thought your saying no the DSM wont do that, and we argued to true things thinking the other didnt know what we were talkin aboot. lol. its sorta funy if ya think aboot it. anyways, it would/shoulda never happened, i blame jonas. lol.

Heat Rave R

Wait, I'm confused: on my thread about bigger injectors for my Z31T ECU conversion, you said it could only handle about 10% bigger than stock without having problems. But if you had 370cc, that's much bigger than 10% of the original injector size.

NismoPick

He was running a SAFC w/ his Z31 ecu & 370's.

lifegrddude

In your original post, you didn't say nor specify if you were going to use anything else as a fuel controller or piggyback device, so I assumed you were just going to use the stock ecu and hope it'd compensate which will never happen on an injector that's >10% larger. As Nismo said, I used an SAFC with the 370's before having my ecu reprogrammed for the 440's (which still needs a bit of tweaking anyway). There was a writeup and a sticky made over a year or so ago since I couldn't find anyone that had gotten it to work on a Z. I would recommend leaning out a lot from my settings though as I was playing it way too safe on the top. My afr's were at 10.1 IIRC. In my opinion it's only safe enough to use the SAFC setup to a max of 1.0 bar of boost, because the maf of the Z31 tends to max out on voltage around 12 or more psi.

thxone

Check it out!!! Stock manifold and I got the BOV on without drilling or welding and it works!!! I had to get a copper plumbing T fitting from home depot and some hose clamps with a plastic T fitting for the vacuum line, total cast about $6. This BOV is not loud but you can hear it very clearly when you hit 10psi and let off the gas. It also did in fact help with the spool of the turbo. So, the BOV works ($17) and no mods to the intake (priceless)

hughdogz

That's pretty cool you can see it from the hood duct!!

Isn't that still partially "recirculating" by Tee'ing back into the intake manifold?

I think the stock plumbing doesn't actually recirculate back into the turbo compressor inlet, instead it bypasses the TB when you let off the boost.

It might run differently if you went straight from the BOV to the J-pipe (remove the tee) and plug the hose going to the intake manifold. I think this way it would vent 100% to the atmosphere...I could wrong though...

thxone

It sort of is I guess but it would be anyway cause that hose would still be there if I ran the BOV in a different location all by itself. So I just combined the two for it's simplicity.

That is how I did it at first...that hose is going to the Air Regulator plumbing. I plugged it and the car wouldn't run. Took me about 15 minutes to settle on this. It is fully functional though and boost comes on quicker now in second, third and fourth. The BOV is quiet with anything under 5lbs of boost but get decent sounding above that. I am happy with it. The only thing this is making me want to do quicker is a fuel rail, 310cc injectors and a FMIC...then I will go HKS SSQV...hopefully at 15psi with that BOV it will be louder

thxone

Well, still no problems with the BOV, I think I have discovered an easy way to mount a BOV with this type of mounting flange.

NismoPick

That's not recirc'ing at all... notice how the BOV vents through those holes... it's not venting back into the intake. SO IT'S NOT RECIRCULATING.

Bleach

but what about the small hose going from the BOV to the intake? isn't that recirculating??

oh wait, no... that's the vacuume line that OPENS the BOV! hahaha!! I figured it ooot

hughdogz

Right for the BOV, but what about the air that tees back into the intake that doesn't go through the BOV?

I didn't literally mean recirculating (back to the compressor intake), that's why I had it in quotes...

It seems to me like the stock setup where it bypasses the TB, but now it has a controlled leak to the atmosphere too. Like you said, if you plug the line going to the air regulator and remove the tee, it won't run right since some air must still be bypassing to the intake instead of 100% through the BOV. Maybe I'm still confused on how the stock setup works...

That's awesome it keeps the boost level up! Do the RPM's still hang during shifts as much as stock, or do they drop faster now?

NismoPick

Which one are you talking about? The hose I've highlighted in red or green? The red one is the stock hose... it goes where it should. It has no effect on the BOV. The green one is the vacuum signal for the BOV.

duowing

Man that's not a bad idea, I might have to pick myself up a blow off valve, but you say that there's definitely a difference when driving around when the boost comes on and what not?