I am currently running a turbo xs open atmosphere blow off valve. That meaning it does not blow off the boost pressure back into the intake. Now my question is, would this hurt the performance of the car? I'm not sure but I am starting to think it would because it would slow the compressor down in between shifts. Does anyone know for sure?

 

Actually, it speeds the compressor up during shifts....The BOV allows all the pent up air to escape, which both prevents the pressure wave from coming back on the compressor, and allowing it to continue to blow air (this keeping it turning)...

Or something like that anyway.

 

Yes, Aaron's right. The BOV blows off the excess air & blah blah blah as he said...

 

Oh boy.

Here's an article on the subject. It's written for Celicas, but you can apply most of the info to any car with an AFM.
http://www.alltrac.net/tuning/bovfaq.html