When the turbo is creating boost and the intake butterfly closes when you let go of the accelerator, it creates a wall at the throtle body where all this air is crashing against, this creates a domino effect that goes all the way to the turbo compressor impellers. it becomes an air brake stoping the impeller from over 50,000 RPMS and even reversing them making a huge stress on the impeller and the main shaft and in the long term, catastrofic results.
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http://www.turbomagazine.com/tech/03...broken01_z.jpg [/IMG]
BOVs make an exit way for the excess air to escape and in turn, it lets the impeller spin freely. The factory one is crapy! If you increase the boost, the factory one opens up and starts to leak. The MOPAR kit bypases the recirculating one making it inop. and it vents to the atmosphere. With stage 1 installed you can hear that a lot of air is release with the MOPAR BOV. IMHO, it lets much more air out than the factory recirculating one. The only drawback is that it is LOUD! but then again, all of the aftermarkets are also. and it is fun to accelerate and let go of the pedal in front of other people and see their reactions... Now I feel like a kid...
You don't have to use the MOPAR BOV, any will do. I got mine from Tommy Thrift. It was 57.00 plus shipping. This a better number than the aftermarkets, 200.00 for a good one.