BOV @ Idle ??
You guys are making this way harder than it has to be. All turbo set-ups have the BOV before the MAF due to tuning purposes. You can't have a BOV after the MAF because it is open at idle and the air being bled off after the MAF has already been metered by the MAF for the ECU so it can tell the motor how much fuel and spark to add, then it wouldn't be entering the intake tract making the car run like crap. Therefore on a Turbo set-up it would be open only until the most miniscule amount of pressure is applied to the throttle and then it would be closed while throttle is applied and starts to see boost build since the BOV is closed and then open once throttle is let off to allow it to open and releive boost. Roots style blowers use BPV since they see boost at all rpm and need the boost to be bled off differently. The only time the BPV is closed is under boost and then once the throttle is let out the BPV opens allowing the air to be recirculated back into the system. On prochargers people use BOV's since they act very much like a turbo spooling up and not creating full boost until a said RPM. So on a procharger set-up the BOV will be before the MAF and same rules apply to it as a turbo.
Last edited by Fbodyjunkie06; Sep 16, 2009 at 06:47 PM.
I am pretty certain my Tial BOV is not open at idle. I am Procharged and SD tuned. I actually have one in each charge pipe before the twin 4.5" intercoolers. Long story.....I have no idle concerns. My concern is without the BOV open at idle that it is working the compressor to hard, deadheading against the TB blade. Decel, even at low RPMs vacuum is higher and the valve chirps or flutters cruising down the road.
Should it be open at idle or does it have to be? There is a lighter spring I can use. According to the vacuum reading I am little tight on the spring.
Should it be open at idle or does it have to be? There is a lighter spring I can use. According to the vacuum reading I am little tight on the spring.
I agree that it makes more sense for it to be OPEN at idle...so long as there is a positive pressure in the charge pipe (which there should be unless you are way oversized on turbo etc. I would think).... But I wanted to see some guys with Turbo cars actually post "yea mine is open at idle"...or " no mine is closed at idle".... and imagine that.... I got some of EACH! LOL 
I am pretty certain my Tial BOV is not open at idle. I am Procharged and SD tuned. I actually have one in each charge pipe before the twin 4.5" intercoolers. Long story.....I have no idle concerns. My concern is without the BOV open at idle that it is working the compressor to hard, deadheading against the TB blade. Decel, even at low RPMs vacuum is higher and the valve chirps or flutters cruising down the road.
Should it be open at idle or does it have to be? There is a lighter spring I can use. According to the vacuum reading I am little tight on the spring.
Should it be open at idle or does it have to be? There is a lighter spring I can use. According to the vacuum reading I am little tight on the spring.
