1JZ stock BOV

[JZA70 R]

i have figure one d/c all together. have no idea what its for. bov works fine without it.

[ReQuieM]

Yeah I've got a mate that does the same. The only thing I can think of is that it is for extra power to open the BOV up. I'd stick an ear close to it to make sure it is working, running no BOV on the 1j sounds very similar but with a bit of flutter. I spose tho you'd need load to get your max boost to check, maybe next time you driving hard pay a little extra attention let us know if it does sound the same. I'm pretty sure mine was fluttering at around 14-15psi when I changed back to the stockie.

[JZA70 R]

mine doesnt flutter, not one bit for any type of driving, currently on 14 - 15 psi....

the only way i can induce flutter is by loading up then slowly backing off the go pedal... really is an addictive sound.

anyway my local mechanic has a dyno dynamics dyno waiting to be installed and im free to use that when hes not busy so perhaps ill check to see how it (figure 1) works then.

[ReQuieM]

sweet. Report back when you can shed some more light on it.

[Ribfeast]

*thread grave dig*

I suspect my factory BOV is leaking, the car seems to be really slow to build boost. But is fine when you mash the accelerator. I converted the stockie into an atmo BOV, and then ran some hose from the outlet into the cabin, so it would discharge onto my legs.

Turns out it is wide open on idle! And as the car as trying to build boost, a portion of it is going out of the BOV, until it finally seals at a couple of PSI.
I'm investigating a few routes -

1. The HKS SSQV which is shut on idle, but $$$$
2. The Jaycar/Silicon Chip electronic BOV controller, which only activates the BOV on sharp throttle closes, and only for a preset time period (usually a second). Purchased and waiting for 3 IC's to arrive.
3. Replacing the 1 way valve or whatever it is with a straight piece of hose. I think all it does is make the BOV close more slowly. I have a nice big 7M 1 way valve fitted there at the moment. No more flutters with the 7M one.

The factory BOV is a clever design as the more boost you run, the harder it seals, but the rubber seal in there is impossible to replace when it perishes.

Any thoughts on the above ideas?

[chris davey]

I suspect my factory BOV is leaking, the car seems to be really slow to build boost. But is fine when you mash the accelerator. I converted the stockie into an atmo BOV, and then ran some hose from the outlet into the cabin, so it would discharge onto my legs.

LOL. For some reason I find that quite funny Good way of testing though.

1. option if you want to spend money.
2. I think that sounds pointless personally.
3. you could try it?
4. block stock BOV and get another one of your choice. Bosch ones are cheap.

[Merudo]

Actually a leaking BOV makes a hell of a whooshing noise at maximum boost - I've heard it on a number of occasions.

indeed it does! another bad thing especially with a leaking BOV is when you've got a 1G and it starts to do the whole overfuelling batman smoke screen thing behind you

[monkeymajik]

5. No BOV (the price is right)

[Ribfeast]

Tried no BOV as well Shoved a lens-cleaner bottle in the hose and clamped it on lol
The electronic BOV controller cost me all of $22, so not a huge outlay.
Does the Bosch BOV stay shut on idle? I want a BOV that does that, as the factory one is wide open until I start to get into positive boost. The only one I have seen so far that does this is the SSQV, as it is dual chamber.
This shows how it works:
http://www.rtec.ch/webshop/product_i...9396d9e44ca2c7

LOL it was a hoot to drive around with the BOV outlet hose hanging through my drivers window, I hit full boost and backed off, and it blew the hose off my lap clear out of the window, probably gave the car next to me a fright Sounds awesome too, have to make a recording sometime.
The air coming out of it wasn't all that warm either which was good. You can hear the air rushing through it until it hits positive boost though.

[EldarO]

that may be why mine doesnt hit full boost till 3,5KRPM, ive seen other 1J's be on nearly the same at 2.5K.

ive already got another atmo bov on there, in addition to the stocker, so ill just block the stocker right off...

cheers for the insight!

Elmo.

[JZA70 R]

i truely believe the stock bov does nothing. all this time i thought the whooshing noises ect were from the bov.

not long ago i took it off and ran no bov and ALL THE SAME NOISES ARE THERE.

too many people have asked what bov i have when there has been nothing on there at all.

i still run no bov to this day and the whooshing noise is just compressed air escaping back past the turbos and out the pod!. keep the throttle cracked while this is happenening and you will get teh flutter.

when you see the diameter of the hold the bov is supposed to breathe through you may understand why its probably not doing anything in regards to venting excess pressure.

could also be because it may not be hooked up correctly... that one way valve and a couple small lines are missing, so yeah. but i still believe it doesnt do anything.

[Ribfeast]

I had the same noises you speak of, until I replaced the stock 1 way valve in the BOV with the 7M one.



Now it just blows off with a huge whoosh, no more flutters. I liked the flutters

This is the hose I ran to the cabin:



And this is the size of the hole on the stock piping that the BOV has to vent through:



This is the electronic BOV controller circuit I soldered together:



Just waiting on replacements for the 3 chips, and some chip holders.

[ReQuieM]

You mean the hole that the bov pulls its air from....

[Ribfeast]

Whoops...yep correct

[naten]

ribfest: how did you go with sorting out your bov?

was it that causing the sluggish felling off the mark or something else?