Anyone else who has the service manual notice there's a section about Turbo care...
 

in the precautions section?

"Precautions for Turbocharger (If Equipped) AAS0001K
The turbocharger turbine revolves at extremely high speeds and
becomes very hot. Therefore, it is essential to maintain a clean supply
of oil flowing through the turbocharger and to follow all required
maintenance instructions and operating procedures.

Always use the recommended oil. Follow the instructions for
proper time to change the oil and proper oil level.

Avoid accelerating engine to a high rpm immediately after starting.

If engine had been operating at high rpm for an extended period
of time, let it idle for a few minutes prior to shutting if off."

hmmm.....

You mean your Z doesn't have a turbo? Something is seriously wrong here. I suggest you bring your car in for service ASAP.