The day before attending a trackday at Rudskogen held by KARN I mounted a cheap oil temp gauge I have had lying around from the old car.
I was kind of surprised and worried when the needle climbed past 125 c after 5 laps on the track.
The OEM water/oil oilcooler looks to be at least twice as thick as the 94 NA item so I can only speculate how high the oiltemp was running when I was boosting 1 bar on my old car with no external oilcooler :-o.

To get the temp down i mounted the same stuff I was running on my previous MX5.
It consists Setrab oilcooler with a mocal sandwich adapter with thermostat and hydraulic lines from the local TESS hydraulic shop.
The couplings and lines are industry standard parts with at least the same quality as Aeroquip and other brands selling AN type fittings and stuff but they are heavier and not made of aluminium. I don't care. The whole assembly weigh less than 3 kilos.
The hoses are steel braided with an additional rubber layer on the outside.
Here are all the parts including the sandwichplate.

The oil thermostat is not really required as this car wont be used in the winter. A normal adapter would also have better flow than the thermostat unit.

The NB model has lots of room behind the left plastic fender. Its also ventilated.

My initial plan was to mount the cooler in the same way as
Daz from did. That was not possible since the IC was blocking the mounting point. The soulution was to fab up a bracket that was mounted on to the tie down hook and a smaller bracket mounted to the outside fender.
The right fog light was removed to get air to the cooler.

Due to the IC pipes the cooler had to be mounted in an angle to the air stream.
Not optimal for the air flow trough the fins but I could always make some additional ducting if this is not adequate.

To make both the mocal and greddy sandwich adapters fit I had to cut of some material from the intake manifold brace.
Some people just remove the whole brace but I'm pretty sure Mazda put it there for a reason.

Everything fits!

The length of the oil lines was meant for my previous NA so I had to make som additonal twists to make them fit under the inner fender.

From the outside:

After a long testdrive on the highway with lots of WOT driving in higher gears the oil temp never exceeded 100c. If I can keep the temp under 110c on the track I'm happy. Time will show.