I have learnt from personal experience to beware what type of blow off is used. I personally like a recirculating blow off valve but have discovered some are better then others. If you're running high boost definetly get a piston style instead of a diaphram style. I was running the stock toyota bypass valve at 25psi boost and at 7500RPM in third my diaphram ruptured and the pintle and spring got free and took a trip through my T3/T4 compressor wheel destroying it in mere seconds without so much as a sound and pumped enough oil into the engine to create the kind of pressure needed to lift my head and destroy every bearing in the engine
. I have switched to a GT3082R with a 38mm sleeper series turbosmart bypass valve as well as forged engine internals and a custom intake manifold. I have no complaints about the bypass valve and is extremly easy to adjust since you don't have to take it apart to shim it just simply turn the dial.