I was talking to my friend who just got a 2002 GTI 1.8turbo. I am not a VW fan but this thing has some ***** even stock. We were talking about his turbo setup and I asked where his BOV was. He said the VW comes with a diverter valve instead of a BOV, and in essence what it does is when you lay off the gas the diverter valve takes the charged air and recycles it back into the turbo acting like the throttle was not let off. Correct me if I'm wrong. Thats pretty kickass. Does anyone know if these "diverter valve" things will work on a custom setup? I am going FI in March and I would rather have something like that then loose momentum with A BOV. Anyone shed some light on the subject? Thanks

DC2R714

 

It wouldn't benifit us since we use a MAP sensor instead of a MAF sensor. In the VW and Mitsu set-ups, the ECU accounts for this air before it goes into the turbo, where as our sensor is after the TB. If you vent the VW or Mitsu's into the atmosphere (like we do) they will not run properly.

 

I'm not too sure about this one, but a BOV vents to the open atmosphere, while a diverter valve blows the excess boost to the intake side of the turbo, after the air filter. This way, the air metered by the MAF is still there, and the positive pressure helps to keep the turbo spooled (a little).

 

that's exactly what it does.