I don't have exact temps, but my impression is that the heatsoak powerloss problem I experienced with my 87 T2 Mr. Grey was cut significantly when I ceramic coated a number of critical parts with the 2200 degree Jet Hot coat, including a hybrid turbo, mani, and a 3" RB downpipe. Oh yeah, I also sectioned into the downpipe a high flow Catco cat, so the engine flows better and is not so corked up like stock.