I'm thinking of running a recirculating BOV on my new turbo setup and wanted to know if anyone else has done it on the xB, and if it would help or hurt. From what I understand, on MAF-equipped cars like ours the open dump BOV are bad because the metered air that went by the sensor gets blown out of the system and not into the combustion chamber when the valve opens, giving a false reading on the MAF. Dumping it before the turbo but after the MAF keeps it in the system and the numbers more accurate I think.

On the Greddy with the Turbo XS RFL-BOV, I would consistantly lean-out when the auto trans shifted into 4th. I'm not sure if the open BOV had anything to do with this or if it was because the auto doesn't tune well below 2.5k RPM. I was on eManage blue and didn't have a pressure sensor.

The new setup will be a HKS BOV, which has a recirculation fitting available, and management will be the AEM FIC with a built in pressure sensor. This is the 365Motorwerks setup.

Is anyone currently running a recirculating BOV and if so does it help tuning / driveability at all? I really don't care about the BOV sound, and actually like the fact that the turbo is quieter than running a header on my cat-back setup.

 

Is your MAF a blow through or pull throw

 

Pull through / draw through, it's the standard setup for an xB with the MAF close to the intake filter and before the turbine. The BOV is between the i/c and throttle body.

It's also hard to find a 1" bung to mount to the intake pipe behind the MAF. The only thing I can find is either a pre-formed T with a 1" nub on a 2" pipe section, or something threaded. I may have to resort to a standard 1" pipe and get it ground to fit the curve of the 2 1/2" intake, then welded. At least it's not aluminum.

 

Update, I never knew finding some 1" steel tubing would be so hard. Can't find it in under 20 foot sections from any supplier, so instead I ordered a Turbo XS mild steel weld-on adapter for their type H BOV's. It's a 1.25" pipe and should work well, it's tall enough to fit a hose clamp over it completely, I'll post pics, dropping the intake off Friday.

 

If you are running a MAF and not Speed density then it would be better to have the BOV recirculated after the MAF and before the turbo. You also want to make sure it is not to close to the MAF or it could disturb the airflow through it and cause all sorts of problems. I would angle it so that is is point toward direction of the compressor wheel . Your not going to find a bung. you can use a tube notcher or grind and file to fit. Of coarse then weld.

 

My turbonetics kit runs recirc and I'm using an FIC with a draw thru maf. My buddy with a somewhat similar kit (same turbo) is running an HKS atmospheric dump on his intercooler and doesn't seem to have any problems with tuning the FIC. I guess it depends on your tuner and tuning device mostly. Injector size and response time might change the result also.

 

Haven't ran the AEM F/IC yet so don't know if it would even be an issue. This was on eManage blue without a pressure sensor. New setup is AEM.

Ended up using a spare weldable Turbo XS BOV mount for the recirc fitting on the intake. it is mounted between the MAF and turbo so it won't screw up the sensor. intake is already angled after the MAF where I put the bung so that should help. Only issue now is if the hose has clearance, won't know that until i do the install.

 

Goodluck with the install and let us know how it turns out. Pics are always nice too.

Kevin