Volvo 850 reculation valve help

[bigty69]

Haha thank you for your help i will be tigging it up today and will post pictures aswell as how it performed.

[bigty69]

Ok stay tuned for some pictures but i have finally did it! I dont have it plumb into the air intake yet but just even venting into the atmosphere my car runs exactly the same no problems what so ever! It holds boost fine and vacuum doesnt leak at all my biggest fear was flutter but i dont have any of it. And i got a really nice psshhhhhhooooossshh when i let off it. The only thing now is i am still running my factory cbv along with it which may account why it is still running so nice. Does anybody know if you can delete the cbv by opening it removing the spring diaphram closimg it up and plugging both air ports? Id like to do it next

[Sommerfeldt]

Good thing erikv got us out of that loop.
As for blocking the CBV, you're better off doing it with a plate - iPD has one for 15 bucks, but you can probably either make one yourself or check Amazon or eBay.

- S

[JDS60R]

Square port

CBV ports

MitsuCBV1.gif (29.03 KiB) Viewed 969 times

The CBV on your car is located on the compressor side of the turbo. It allows (under the right conditions) the air to escape from the OTE tube backwards around the compressor blades and gets resent through the compressor. It does not allow air to pass backwards through the MAF. You are correct that you want the air to be sent back into the turbo and not be recounted by the MAF. Recounting the air by running it through the MAF again would cause an over rich condition. So does venting it to the atmosphere (not running it through engine) .

When you look at your turbo compressor blades you will see the square port right before the blades- this is where the CBV air enters (re-enters)the turbo.
There are replacement CBV's that can easily handle the flow you are looking at - or of course you can make your own.

You will want to block off your damaged stock CBV if making your own so it doesn't bleed off boost.

[bigty69]

Oh i see thanks for explaining that i have always wondered how that worked it litterally moves the boosted air right back to infront of the turbo inlet. I will be making a plate up today ill let you guys know how it goes. I put some good mileage on it yesterday and it performed awsome.