You have turbulence there being the air goes from coming sideways to turning down into the carb. But, the hat would have to be tiny to gain 125+ degrees in 10 seconds. Are the intake runners flaming hot as well?
If you have a wastegate on the turbo, you could back the boost down and see if there's a point where you stop generating so much heat.
Boost is just a pressure reference after all, more pressure=more heat.