the biturbo is actually very quite if it is tightend to the engine properly. I had the same problem you do with the wrench fitting. you may not want to do this, but i removed the exhaust studs, and used allen bolts to hold the pipe in place, that way you can tighten it with getting the wrench in the way. however, they did come loose every month or so, so you might want to use lock-tight or something