We have similar discussions on the rotary forums (due to the temps the Wankel engine runs at!).
Most seem to agree with many of the above comments - oil cooler (for us Rotary boys that means getting a second cooler to aid the first one!), bigger rad, better rad ducting.
Undertrays seem to work very well on the rotarys - something to do with the low pressure under the car sucking air in to aid with blowing it into the bay or something (I used to understand Physics being a UCL honours Physics graduate, but the knowledge escaped me when I left university for the real world).
Similarly, there's huge debates about "bonnet lifting" (in your case, running the Z with the bonnet on latch). Something to do with there being designed a high pressure area at the base of the windscreen, which when you lift the bonnet at the windscreen end actually pushes the hot air back into the engine bay, rather than letting the air flow through the bay and out at the windscreen.
As such, to summarise what we do, add an oil cooler, up the radiator core size, duct air too it better (it sits as standard infront of the intercooler as an FYI) and pop an undertray on to utilise the air flow from under the vehicle.