you have to be a little causious on this one. I researched this for a previous turbo project with jet-hot. the main point is that you don't want any component coated directly in the exhaust stream prior to the turbo. The reason is pretty simple. over time the coating can weaken and flake. If they come loss and meet the turbine wheel .. you get the picture. Coating the manifold and turbine housing exterior, great choice.
