Ok, I messed up my wording a little bit. Our factory valve (along with almost every other factory turbo car) is considered a BPV which is basically just a BOV run in recirc. When you let off the gas the valve allows the pressurized air to Bypass the intake and be returned to the intake. Under no/light throttle the valve stays open (under either of these conditions the vacuum in the intake is pulling the valve open) which allows the air to Bypass the turbo and run the car as somewhat of an N/A and gain you the benefits I mentioned above. VTA became popular because of Honda (They contribute to more rice per capita than any other car maker in history). Honda used to, not sure if they still do, rely solely on a MAP sensor to read air flow to the engine. It was cheaper to manufacturer than MAF's and Honda wanted to keep their prices low. Because these sensors are placed in the intake manifold it didn't really matter what happened before the throttle body. So when it came time to turbo these cars it didn't harm the fuel trim to run VTA. Hearing all the PSSSSSSSSH noises gave America a rice boner and people started thinking "Man, that car must be fast if it's that loud." If you are running a MAF car than recirc will give you the best performance, fuel economy, turbo response and tuning capability.
Those anti-stall modules came about because people wanted the ricer noise on their MAF equipped cars but then bitched when they ran like s***. They keep unmetered air from being sucked into the engine while the valve is open at idle. The fact that you have to buy extra parts and tune the motor a certain way to make your car run properly should give it away that VTA is just dumb. I know a lot of people find this hard to believe, but just because it's a trend doesn't make it right.
I HIGHLY recommend running the DISI motor in recirc. With the picky fuel systems and strange quirks these engines have there is no reason to make it run even weirder.
. That's when I decided to get rid of it.
