Always trying to be cool!
Ken,
When I had my V8 Fiero I ran into some problems keeping it in a safe cool zone. It never boiled over, but would get pretty warm on the highway, and actually cool off in traffic.
One day while cruising down the highway, I pulled the hood latch (No worries, they open backwards like Vettes). This let the high pressure air escape from behind the radiator faster. I ended up with a 40 plus degree drop.
So, I won't go into the details of how I then modified the car to stay cool as that is way off topic. What I can say, is it made a huge difference on that car. Bottom line is, the radiator is only as efficient as the air that can travel through it.
One other trick to try. If there is anyway to extend the factory air dam that is in the center of the nose closer to the ground. Here is the scoop (pun intended). The lower that is to the ground below the radiator, the higher the pressure that it forces into the front of the radiator, and the lower the pressure behind to help direct the air up over and down. After making the front chamber mods on the Fiero I saw the 40 degree drop. Then, I lengthened the front lower scoop, and dropped almost 40 more. I ended up taking the lower scoop and trimming it to half that size. That kept me at 180-190 in the heat of summer with the air on high.
With all that said Ken, Nikki's 90 won't get hot now. We put a pair of new cooling fan motors, new stock replacement radiator, 180 Robertshaw High Perf. Thermostat, and cleaned out all the crud up front. Finally, I rewired her fan so one comes on and stays on with the engine, and the other only comes on with the a/c. I can't get it over 190 (except at AutoX where it hit 195 or so after 75 seconds of WOT and brakes).
I plan on rewiring her primary fan on a simple thermostat sender that will kick the fan on at 180, and off at 160. This will help while cruising down the highway as it will most likely shut off and let the cruising air do the trick. In fact, the electric fan is a henerence at speed, as the natural force of the air is greater than what the fan can pull.