I had one of those on my ST. Didn’t notice any leaks at all. And I was full stage 3 and tuned running 24 psi of boost. Sounds similar to a turbosmart BOV. I ended up getting a Tial BOV instead. Sounded way better. I still have the adapter if you want it. There’s no way I’m putting it on my RS.. I’ll be going the same route with the Tial BOV. I could do $20 plus shipping to you if you’re interested. You will need 3 new longer screws though as I have lost the ones that came with the kit.. You should be able to find some at Home Depot or Lowe’s. PM me if you’re interested.