sirx7

HI i did do search and all i saw was lot of crap about the everything but what i was loking for (so iguess it not crap but jsut too much info and i could noyt find anything relevant

anywasy i have seen a lol of pics with this setup but all teh write up is in japanese..so i figure d i asked the guys/gals on here for opinions..

please see pic

sirx7

here is link for graphic

pardon my crude drawing using paint

Cosmo Donk

In the words of the Croc Hunter, "What a beauty!"

I have seen Japanese cars with that set up and it has come across these pages at some point and the consensus was that it will work fine. The only thing I would change would be the location of the BOV, I would put it on the other side of the MAF.

sirx7

now running this kinda setup ..how will it effect your air/fuel ration since there is more air. and running an opev BOV will it damage the plastic cone...inside the afm

Cosmo Donk

Well, this is what I always wondered. You aren't actually running more air though, just compressed air so that part won't make a difference. The part I wondered about is how far the flapper door gets opened since it is compressed air.

Running the open BOV will not do anything to the flapper but will cause drivability problems because of the sudden release of metered air.

LT8TurboII

iTrader: (2)

Where he has the BOV in that picture it is not releasing metered air as it is before the meter.

Cosmo Donk

Hmm, good point. I wonder what would happen in that situation.

sirx7

well i looked at the afm and it looks like a check valve like if air went backwards through it...would remain closed..and in all the jspec pic that is how it is setup...so iam lil confused as to waht happens when you let off teh gas pedal..does the pressure build in everything an then it triggers the bov or is taht opened by some other means and just release spooled up air with out affecting the AFm and blowing my enngine


i hope this makes sense..

ok here is teh question can i run open bov just like taht setup and has anybody done it..like i arunning a chipped ecu but nothing extreme

sirx7

no one have any other thoughts

Evil Aviator

My thought is that the stock AFM and ECU need to be replaced, and moving the AFM is simply a waste of time. I remember "back in the day" when moving the AFM was a good idea if you added on a lot of expensive whiz-boxes, but those days are long gone. It would be like looking at hotrods from the 60's, and concluding that bias ply tires and leaf springs were a good idea for your RX-7. A standalone EMS is the way to go. You can get a decent EMS now for about the same price as a Racing Beat carb kit, so it's not like it is an overly-expensive proposition anymore.
http://www.rx7store.net/product.asp?0=208&1=297&3=791

A BOV is activated via a vacuum line that is attached to the intake manifold. When the throttle is closed, the intake is under vacuum, which sucks the BOV open and lets the boost out of the system. Diagram and explanation of a GReddy BOV at the bottom of this link:
http://www.935motorsports.com/greddybov.htm

Placing the BOV between the AFM and the intake manifold will cause problems because the engine will not get as much air as the AFM thinks it is getting. This causes an instant rich mixture, which causes bogging and hesitation. This is why a stock TII has a bypass valve, which is a BOV that recirculates the metered air, keeping the air/fuel ratio correct.

A BOV or bypass valve is best placed in a low velocity (high pressure) area of the intake system, which would favor either right after the turbo, or right before the throttle body. However, if there are fitting problems with either of these two locations, you can still place it elsewhere, although it will not work quite as efficiently.

sirx7

mr evil:

can i place my bov before the afm just like in my setup i moving the afm more for fitment issue..than power adder..the othe rreason i moving the afm is casue that way whean to atmosphere i will not be releasing metered air..my boc is right after the tubo in diagram it isshown there so ppl will understand taht it is before the AFM...this how my setup is really set..

filter>(afm1)>turbo>bov>ic>(afm2)>engine

so i would like to move the afm to position 2, as then the air released will not be metered and my car will not go into rich postion.

Evil Aviator

I think it would be easier to just keep what you have, and add a pipe that vents the BOV discharge to an area between the AFM and turbo. This setup would be closer to the stock setup, so the stock ECU would be more accurate and would not require much tuning from the aftermarket fuel computer. If you move the AFM after the turbo and intercooler, you will need to totally retune your aftermarket fuel computer.

sirx7

i am using safc2 to tune my car...if i have to recirc my bov i iwll need to get a new one..the whole idea of doing this is so i don't go rich when i let off the gas.