Quote Originally Posted by KPowerEP3
Well, it's an internally gated turbo [mitsu], and like I said in the OP, I want to fab up a tubular O2 housing, and I know some people claim gains with an external, and others say it's just for noise. I was mainly looking for the fluid dynamics aspects of it like Big J posted, from some one with more knowlege than I. The noise doesn't bother me, but it isn't necessarily a plus for me either.

oh and just FYI[blackshine and big j]...my BOV is recirculated....I'm not one of those 'look at me, my car is turbocharged' guys, I don't want too much unnecessary attention.
On a car that came out of the factory with a recirculating BOV or any car that has a MAF sensor before the BOV outlet on pressurized intake side the car should run better. If you run open atmosphere you are dumping unmetered air that ECU will think is there. When you vent it will cause a temporary rich condition. That combined with the a slight loss of momentum of the compressor wheel will make you lose power as well as take longer to respool the turbo. If you were running speed/density then it really wouldn't matter since you wouldn't really have a way to recirculate it.

I have a few different BOVs sitting around that I've installed my car: HKS SSQV, Blitz SS, recirculating stock BOV, and Greddy Type-S. The recirculating Type-S is by far the best performing BOV after being properly adjusted properly - for now. I'm switching to speed/density soon so I'll be removing a lot of pipes and changing BOVs again.

Open atmosphere will work (although I've heard issues of cars stalling after venting while running open atmosphere after a gear pull to redline), but closed loop really is the best for most cars.