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 you let off the gas. If you suddenly vent that air to the atmosphere, the computer doesn’t know it and your engine will run quite lean at high RPM’s and that over time can do some damage. HKS unit’s are known to make the car idle funny and bog between shifts. So will others but I 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 PSI of boost. If you are just after the sound, there are a couple of short ram intakes out there that do not mess with the MAF reading and are fairly safe to put on your car. Cobb and SPT are two and I think Perrin units are good too. Others will mess with readings enough to cause odd engine behavior so better to avoid them. I love these cars but the first thing you 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.
don’t do it, you dont need, waste of money and a chance you can mess your car up. Subaru’s do not need them, the air automaticall goes into your intake anyways.
besides… I would much rather have a car that sounded like a sleeper. the guy will be PSSSSShhh PSSSShhh while he looks at your tail lights
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 you let off the gas. If you suddenly vent that air to the atmosphere, the computer doesn’t know it and your engine will run quite lean at high RPM’s and that over time can do some damage. HKS unit’s are known to make the car idle funny and bog between shifts. So will others but I 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 PSI of boost. If you are just after the sound, there are a couple of short ram intakes out there that do not mess with the MAF reading and are fairly safe to put on your car. Cobb and SPT are two and I think Perrin units are good too. Others will mess with readings enough to cause odd engine behavior so better to avoid them. I love these cars but the first thing you 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.
don’t do it, you dont need, waste of money and a chance you can mess your car up. Subaru’s do not need them, the air automaticall goes into your intake anyways.
besides… I would much rather have a car that sounded like a sleeper. the guy will be PSSSSShhh PSSSShhh while he looks at your tail lights