I had a test pipe running on the Cobb OTS Stage 2 tune then eventually the stage 3. The OTS maps are relatively conservative so safe with a test pipe. I'm tuned by CBRD with ECUflash and a MAP open dump and couldn't be happier. Like others have said, recirculated DP wouldn't be worth it on the stock turbo, unless you go o2 elim. Just be prepared for the gates of hell to open whenever you hit boost.