3rd gen guys.. help me answer this BOV/BPV questions...
 

Please check this thread and give me your input.. I'm having hard time with this kid.. Maybe I'm wrong about what I'm saying and I need to be corrected..

https://www.rx7club.com/showthread.php?threadid=259383

Thanks!

I beleive that with a bypass valve air is able to "leak" out of the bypass valve while under low to intermediate throttle, but under heavy exceleration the plate in the bypass valve is closed, then opens again to let out the remaining air when the throttle is released. With a BOV I beleive that it is not supose to "leak" air under low or intermeadiate throttle, but after heavy excelleration and instant release on the throttle quickly shutting the throttle body and stoping positive air flow throught the intake pipe, this is what opens the plate on a blow off valve releasing air pressure. I am not sure if I am completely correct or if I explained that very well at all, if I am completely wrong just call me a moron and explain why I am wrong

aren't mr2's mass air flow cars? he can't vent because the sensor needs the airflow. idle will suffer with it vented. i'm pretty sure

it will cause the car to run very rich when the bov releases air because the car is expecting it and injects fuel for it but it is put into the atmosphere

rx7s dont work like that

But my question is... Does it have some sort of spring to close when it makes that transition from throttle plate closing and opening back up to accelerate?? I do understand that it has AFM or MAF.. but he's saying there is NO spring or some sort of tension to close the bypass valve.. just pull/push via vac and pressure. Also, running rich for short period of time with BOV isn't bad.. just idle or slight jerky when shifting.. That's my guess..

yeah my roomates car has shut off while shifting from 1st to 2nd and then slowing down real fast supras have a problem with this

no the valve must open and close why the fuck would it be a valve if it was just opened all of the time they could run a hose instead right?:D
you can test any bov yourself...try to blow through it and you cant then put a vacuum line to the nipple suck in as much air as you can....youll hear the spring inside move and then crimp the vacuum line with your fingers...now you can blow totally through it

phil
 

This is what I was getting at the other night...it's the same on the Mazdaspeed Protege.

Re: phil
 

Matt, I understand.. my main concern is not because of its venting back to the intake for the AFM to read.. but how does it suck air into the BPV?

but regard to venting back to intake, how does that effect?? can someone explain to me how not venting and venting would create problem.. and does it make any difference if you take the stock air box and put aftermarket filter?? I might put GTE engine into my celica..

In mass air flow metered cars that are turbocharged the blow-off or by-pass valve vents pressure back into the intake tract after the throttle body or else they would stall or hesitate .It calculates fuel for that air your trying to vent.