Stock BOV questions
 

Hi guys,
I think I saw what seems to be like two BOVs. Is that because of the stock twin turbo set up? They look pretty much identical. I also took off the recirculate hose that went into the stock airbox. It goes into the air now and makes that "psssh'' noise. Will doing this harm the engine or turbos?

The two you are lookin at should be labled crv and abv ( i think) remove the air bypass valve from the stock airbox if you want the psssssh sound. It will not hurt the engine.

The only downfall i know of by turning the stock bov atmospherical is that it may make your car run rich because your ecu will measure the air flow and then flow the right amount of fuel for that amount of air. When you blow the air off into the atmosphere then it still uses as much fuel as if it didn't toss the air out. There have been arguments if it really effects it that bad but also there is really no plus side to having the bov atmospherical if your running close to the stock psi, besides the "pshhht" sound which is known as a "ricer" sound but hey, i like the sound but not sure if i'd be willing to risk my car to run rich to get it but its all upto you. there are lots and lots of threads that probably explain it better, just use the search tool bro :icon_tup:

^ FD Rx-7's do not have a Mass Airflow sensor and are thus not affected by an atmospheric vented blow off valve.

The 2 Valves you are referring too are different things only if you are running the turbos in sequential. The forward one is the BOV. No problem with venting that one. The rear one is a CRV (Charge Relive Valve). This vents the pressurized air from the secondary turbo while pre-spooling to prevent turbo surge and extend the life of your secondary turbo. When running the turbos in sequential you will get a "MOOOOOO" sound of this if you are venting it. No harm done just a it of annoying sound. If you are running the turbos non-seq. then CRV acts a second BOV. They are both the same part just have different functions.

You won't get a moo sound from venting either of the stock BOV's, only from the air pump return line, that's the source of the moo.

As stated, the car will run just fine with them open air vented, the FD doesn't have a MAF.

Dale

Thats right, speed density base system. Im not sure why i rambled off that :lol: thanks for clearing that up :icon_tup:

That's right...it has been a while since I had an airpump and ran sequential.

If running no-seq cap the rear bov, and use the front only, simplify the system. I've been running mine like this for quite some time now.

Oh okay thanks for the replies. So no maf right? Now I know what it would do if it did have one. Thanks fromtib. Hmm my fd is completly stock. Does that mean its running twin sequentials?

Most likely it is still runing sequential if it's completely stock, If you still have the rat nest then you have it.

yup rat nest is still there

I just took the hoses out of the airbox. If i took the hoses off the BOVs themselves would it make the noise louder? I also have another question about intercooler hoses(sry for not making another thread.) I saw on rotary performance that it had a greddy kit like one was Elbow only, 2 piece kit, and 3 piece kit. They all had the option of a "boss". I don't really know what that is. Is it needed or would the kit without it be fine? Here's a link to it:
http://www.rx7.com/store/rx7/fdintercooler.html
it's the second to last thing if you scroll all the way down.