dragger

Hey Guys. I am new to the RX-7 Scene. I was wondering if you guys can help me install the BOV.
Basically, someone hook me up with a BOV w/o instructions. How do I start to install it? What is the hard and soft screw stand for? Any help would greatly be appreciated.

Thanks.

coop

I would like to know this too....There is the large opening and the smaller one (on the adaptor that bolts on the bottom) which side is in and which side is out??? It looks like the bottom (with the 2 bolts) is input...?

darkside7

iTrader: (12)

is this a rx7 kit or just the BOV??????

coop

I purchased mine used...all I have is the Bov and the metal arm that bolts on under the BOV. I don't know what any of the openings are for...which one is the one to control the BOV? Why are there two arms off the top (one slightly smaller than the other)?
I can attach a pic if that would help...thanks
-Dave

Trexthe3rd

Holy ****, this thread started in August of last year and just got dug up again??
Anyway, here is the answer to your question.

The vacuum control line input goes to the nipple near the top of the BOV (the horizontal one), the easiest source for the vacuum control is teeing off the vacuum hose right at the side of the intake manifold (passenger side). The other nipple has no connection to it (the one sitting at a 45 deg angle).

The big openning (pointing in the opposit direction as the vacuum control input) is the pressure relief output, no connections there.

The smaller opening is where the input hose (7/8" I think, the same hose that goes into the stock BOV) is attached.

The bottom of the BOV should have a block off plate bolted to it. This is only used for cars that have a BOV flange on the turbo output pipe (typically in single turbo applications with FMIC), in that case the smaller opening mentioned in the last section is blocked off. If you do not have a block off plate there and you don't have a BOV flange on the turbo piping, then u'll need to buy/make/come up with a block off plate.

As for the harder and softer setting screw on the top, the easiest way to explain is this; softer = louder, harder = quieter. The harder the setting the quicker the BOV cuts back on the pressure relief (faster response time, less pressure relief), in theory, allowing the boost to build back up quicker. Softer setting is vice versa, slower response but more pressure relief.

Hope this helps.

JSpec

I'm putting my Type-S on a Greddy elbow, and figured I only need to take the vacuum hose from the intake manifold (right nipple) and connect it to the upper nipple of the BOV. My question is, what do I do with the stock BOV? I'm using an APEXi Power Intake, and I figured I'd just cap it off before it hits the stock BOV and remove it.. Is this correct thinking?

Trexthe3rd

I wasn't aware that the Greddy elbow had BOV flanges on them, did you custom manufacture one?? If you did, here is what you'll need to do:

1. Install the Greddy BOV onto the flange.

2. Disconnect the vacuum control hose going to the stock BOV and connect it to the Greddy BOV. This is it, as far as installation is concerned.

3. This is where you have a choice, you can leave the stock BOV and cap off the outlet (without vacuum control the BOV shouldn't open anyway, but just to make sure). Although I'm not sure why you would want to keep a useless stock BOV there? The second choice is to remove the stock BOV and cap off the inlet end.

coop

Great! thanks a bunch Trexthe3rd! One final question...do you want your BOV to discharge to atmosphere or hook it back to the intake...(I have an Apexi Power Intake)
Thanks a bunch
-Dave

JSpec

Yeah, Greddy makes an elbow with a flange already on it, it's one of the options just like the injector bosses.. I figured I'd cap off the the end of the Y-Pipe (going to the BOV of course) and the end of the Power Intake (although there's no reason to, I might as well). I figure from the picture that the intake nipple of the Greddy BOV doesn't need to be capped as well.. Thanks for the info Trexthe3rd..

coop

Correct me if I am wrong...(I am still trying to learn this stuff)
But doesn't the BOV let the turbo either a.) discharge what would be boost to the atmosphere or into the intakes and b.) close off that hose so the boost is then spooled...?
I don't understand why Jspec would have the BOV on the oppsite side of the car from the turbos...Is there a hose run over from the turbos?
Thanks
confused Dave

m0t03

does anyone have any good pics of their BOV installed w/o the greedy elbow just to the stock intake or aftermarket intake, I think this would help me out tons. thanks,

JSpec

I have the RX7 kit for the Type-S, and it basically takes the hose running from the Y-Pipe to the stock intake and makes you shorten it. Then you put the adapter onto the flanged part (the bottom) and hook the hose to it (after removing the stock BOV of course). Then you take the vacuum hose from the stock BOV and put it on the upper nipple of the BOV. The BOV then mounts to the bracket with the 4 relays on it (small rubber covered boxes). I'll scan pics of the instructions, though they are faily worthless. This is all and well, unless you have the APEXi Intake, because it too uses the same mounting area. So if you do have the APEXi intake, you can lengthen the hose to the Y-Pipe, not mount it and have it underneath the intake (hard to get too), or stick it somewhere else..

As far as having the BOV on the other side of the turbos: It doesn't really matter where the BOV sits between the turbo(s) and and the intake manifold, so long as it IS before the intake manifold. It just means it'll run through the Y-Pipe and the intercooler before it get's to the BOV. The boost should be relatively the same in the Y-Pipe and intercool piping (yes the pressure will be slightly lower after the IC, but you get the point). You mainly see aftermarket BOVs sitting on the intercooler piping before the elbow (common with the HKS units).