I think you are overspeeding the turbine. Most turbo machines need some back pressure so the wheels stay loaded during an off throttle periods and sudden load changes. If I recall those turbo adapters are a restrictive office. Ford did not add that to reduce power, it was surge protection. Combine that with all the other mods, you have over speed. When you chop the throttle the compressor wheel side stops working, unloads, causing over speed. Ask your manufacturer about compressor surge. Also, the thrust washer is purple, symptom of compressor surge.