Extreme temp thread locker (like Loctite) rated for turbo applications, good to 2100 F - much higher than any turbo hardware will see.
Use for securing studs in header flanges. Have problems blowing out turbo gaskets? Its not the gasket that fails, its the hardware loosening allowing hot exhaust gas to burn away the gasket. Prevent these sort of failures once and for all with a proper, temp rated threadlocker.
Granted, its not cheap, but either are loose turbo and manifold hardware.