I have seen numerous cars at the Track and in town that have their BOV configuration a little different. I was wondering what the advantages and Disadvantages are for having it this way.

The hose that goes from the BOV to the Cold Air intake is removed and the large nipple on the cold air intake is capped off and there is nothing on the exhaust post of the BOV. here is a picture if you dont understand

 

advantage, none
disadvantage, run bad, power loss and many others can add

 

For an evo what they call venting to air is a bad thing. The car wants to stall at idle and runs like crap. On some cars that have speed density and use a map sensor there is no adverse affect. They can run vent to air with no problems, that an evo or other maf cars would run into!!! I hope this helps.

 

If you want a ricey BOV sound go ahead, EVO's have a MAF sensor that has already counted that air and calculated the fuel input for it you will bog down/run rich when that air is supposed to be there. If you are running stand alone, like an EMS, then you can change to a MAP sensor and take out the MAF which allows you to run open atmosphere BOVs

 

WOW see i didnt think it would effect how the car runs because i thought it was just the extra boost releasing and it wouldnt matter since it just vents into that hose and into the CAI. Thanks though. i am glad i didnt try it

 

I'll chime in because our valve is used in the diagram.

Essentially, what you're describing is converting a recirculating valve into an atmospheric valve by simply bypassing the recirculating connection.

This is not something typically recommended unless in such an instance where the car in question has an engine management system capable of compensating for the use of an atmospheric valve. (MAP-based instead of MAF-based)

The OEM MAF-based ECU requires the use of a recirculating valve, so by not using one, you will notice a rich fuel condition, a potential loss of power, and potential driveability issues.

I have done plenty of imperical testing of our own recirculating and atmospheric valves on my own car and found the use of an atmospheric valve on the stock engine management to result in such a rich fuel condition that a 40-45 mile per tank reduction in fuel economy resulted, as did a loss of a few horsepower. (this will undoubtedly vary based on the specific tune of the ECU)

If you want to upgrade to a MAP-based engine management system, that will allow you to use either an atmospheric OR a reciruclating valve, the choice is yours.