l was just wondering if you could put a BOV in to a sti.... l heard taht you could damage the car ????

You heard right. The BOV releases the air back into the intake tract after the MAF sensor right before the turbo. Because it happens after the air flow sensor, the ecu is programmed to automatically dump a little extra fuel when u let off the gas. If u suddenly vent that air to the atmosphere, the computer does not know it & ur engine will run quite lean at high RPM is & that over time can do some damage. HKS unit is r known to make the car idle funny & bog between shifts. So will others but l have heard HKS is the wost of them all. There is no power to be made by changing BOV as the stock unit is shown to hold upwards of 22-23 PS l of boost. If u r just after the sound, there r a couple of short ram intakes out there that do not mess with the MAF reading & r fairly safe to put on ur car. Cobb & SPT r two & l think Perrin units r good too. Others will mess with readings enough to cause odd engine behavior so better to avoid them. l love these cars but the first thing u need to learn is the ECU is very picky about any modifications to it. Basically with new open loop/closed loop tuning, it does not make adjustments do different conditions so everything needs to be tuned for.

The only benefit is sound and you are hurting performance.

Since you lose the air, there is extra fuel. Therefore the car runs rich, not lean. The bogging in between shifts comes from running rich. Running lean would make the car faster. right before it burns a hole in the piston. :)

do not do it, you dont need, waste of money and a chance you can mess your car up. Subaru is do not need them, the air automaticall goes into your intake anyways.

besides. l would much rather have a car that sounded like a sleeper. the guy will be PSSSSShhh PSSSShhh while he looks at your tail lights