I live in Coachella Valley, where a cool day in the summer is if the ambient air temperature is about 90-100 outside. A couple people down here have Turbo IIs, but I've only seen them either at night, or in a parking lot. I was wondering how well do Turbo IIs and NAs do in 110 degree heat with stock intercooler?

 

that is a good ? I would like to know my car seems to be hard to start when it has been driven in 90f heat

 

I guess you ment radiator

I heard the rx-7s with the 2nd OEM electric fan were sold in hot regions. I'd assume you might want to have that in death valley temperatures or any desert temperatures.

The OEM 2nd gen radiator is pretty good actually (unlike the 3rd gen ones).

If you mean intercooler, I'd imaging a good water-air intercooler might be a good upgrade.