Last Friday , with my friends , we had done a track-day on Adria circuit ; it's a new italian circuit where run also the car of DTM , like Audi , Marcedes , Opel..
The circuit is very well and it's more technical than fast.
I did two turns of twenty minutes each to more understand my new 350Z (1300 Km) ; I'm very happy , the behaviour of 350Z , with Borla Cat Back , is excellent ; after five minutes i took off the ESP control and the car was more enjoy to drive.
My question ; after the both turns the steering oil was boiling ; it was evident to see the small transparent tank.
What's your opinion ?
All is normal ??

 

It could be aeration. You can see bubbles in the reservoir tank. Make sure the PS fluid is at the correct level when cold (or hot if there is a hot fill line). If it's correct and it still aerates, there's nothing much you can do to fix it because you can't change the design of the reservoir. Lateral g's and heat cause it to aerate. Not a big deal, you might hear some pump moan/groan. Extreme aeration will eventually lead to cavitation in the pump but that's if the fluid is way below the fill line.

 

There is a larger power steering cooler which NISMO offeres. You might want to look into it.