Red hot turbocharger.

Supposing that everything is well designed, two problems occur to me capable of making turbo to go red hot:

1-Exhaust system restriction, causing backpressure into the turbo.The very long and small diameter exhaust piping would cause the same effect.

2-It is a very common cause of turbo overheating the excess debt of fuel to the injectors or, causing the same effect, one or more injectors dripping fuel into the cylinder head (worn out injectors).Look for others causes of excess fuel debt.