TwinTriangles

Ive been wondering this for a while now but... when I bought my FD it came with this setup piping the 2 BOV's together and then a little K&N filter on the end, why do I have a filter on my BOV's anyone know?
JDub

c00lduke

because some thinks it looks good, some might just see it as a hole they have no clue about and think better to be same then sorry

TwinTriangles

But why? I think it looks ugly and Im wondering if there is some hidden reasoning behind the whole thing...

dis1

The stock BOVs on the Rx-7 draw air in to the engine when under vacuum. Normally BOVs only prevent air from escaping except when they need to vent like between shifts. (duh) So basically then need to be filtered unless you don't care about bugs and dust going in to your engine.

GoRacer

iTrader: (2)

Dis1 (above) gave a similar answer that Tri-Point did when I asked them. Blitz offers a filter as an option to their BOV.

maxcooper

Do the BOVs and the air pump all connect to the same "manifold"? If so, the filter might be to clean the air the air pump gets.

-Max

LAracer

So on a stock FD does the BOV connect to the filtered side of the airbox? If so, and if the BOV really does suck as well as blow (hehe), then venting the BOV would be a bad thing, right? Why do so many people vent the BOV if it is bad?

dis1

Yes, on a stock 7 the BOVs do connect to the filtered side of the air box and yes it is a bad thing if you vent them w/o a filter. The reason people do it is because they are ignorant. Only aftermarket BOVs should be vented w/o filters.

SleepR1

The CRV and the APV valves do very different things. The CRV, charge relief valve, vents secondary boost back into the secondary turbo between 3000 and 4500 rpm to keep the secondary turbo prespooled until the switch over point @ 4500 rpm. The APV, Air Bypass valve (commonly known in the rice circles as the blow-off valve), vents primary and secondary turbo boost when letting off of the gas. There should be a filter on the Air Bypass valve since oil does tend to shoot out of it (if you don't have the ABV connected into the stock air filter box).

LAracer

Well, since this thread is dug up anyway...I noticed that on my PFS airbox, the ABV and CRV vent to the unfiltered side of the box. Hope they don't suck too much air.

rynberg

As far as I know, all of the box intakes work like that. Besides, if you look at how air moves into the PFS box, you will see that it pretty much has to go through the filter to get to the top side of the box where the ABV and CRV attach (at least, as far as I remember...). When I bought my PFS intake used, the top side of the box was pretty clean, while the pre-filter portion at the front was nasty.

dis1

I may have to take back what I said on this topic. I have been hearing different stories now... I'm going to test it for myself to learn the real truth.

tbonerx7

I've got the Apexi Power intake as well as the non-sequential mod.

I vented my the blow off valve because it sounded good. Then, I came to my senses and re-connected it because there wasn't anything to plug up the Apexi intake. Rotaries don't really like dirt.

What do people use to plug up these 3/4-1" diameter tubes from the intake? The vacuum plugs only go up to 1/4 or 1/2 an inch. Is there a big rubber cap I can clamp? Where would I find that?