Thread: Educate me on BOV flanges

Maybe someone can answer this,

I have this SR20VET recirc valve. I want to use it on my build. I took some measurements,What is the hole marked with red arrow?


I want to fasten it to this type of pipe. Too small flange, so I need an adapter.


Can I use a RB20DET flange adapter? (the wrong way lol)? Stock->Blitz


How do you guys fasten these?

Mines came with Allen bolts and I used Allen keys to take mines off not to long ago...

That hole is there to open the BOV if the charge pipe sees too much boost. You should be able to modify that adapter with a file or some such to allow that hole to get charge pressure and still seal properly.

Or if you want, you can vent this thing to atmosphere like the DSM guys do. They bypass this feature on their BOVs so they can hold more boost. http://www.thedodgegarage.com/turbo_bov_mod.html

To vent to atmosphere you could drill or cut into the passageway on the side of the BOV casting instead of trying to figure out how to deal with the port hole.

Ah, so that was what the little hole was used for. Thanks for enlightening me!

I ended up welding a custom flange for the BOV, didn't have time to order overpriced ones from ebay.

If you can, get that MAP sensor on a dedicated vacuum line.