I've probably brought this on myself. I'm in Georgia, and after going turbo and MS3, I finally sought out this summer to get my A/C working. I got it working, but my water temps were headed towards the 250 mark. Previously ran my cooling fans ganged, and while I was running on the warm side (220ish), once the fans were unganged I wasn't getting enough airflow through the rad at 70mph.
So I went ahead and properly shrouded it. Temps were good throughout the summer, 180-200 with A/C on. But the weather has turned - I took the car off the road for a couple of weeks while I did some work and tonight with a 35f ambient, my water temp maintained 135f at 70mph. Oil was on the low side at 180. When I stopped for 3 minutes, the water temp raised up to 170. I stopped to get gas, and the radiator was warm (but not scalding) - so I believe the 120f is valid.
So - obviously - my shrouding is working pretty well. I've also got a few cooling mods..
m-tuned reroute, 190f tstat, godspeed radiator, radiator shroud and upgraded fans, louvered panel on a low-pressure area of the hood facing the correct way. Should also mention a racing beat type 2 nose, so the mouth is a bit bigger as well. I deleted the hard-pipe water line, blocked off the tstat housing, and proceeded to run a stainless steel hose from the heater core to the lower radiator hose to get a little mixing manifold action going on. So my cooling looks a bit like this -
With this setup, I'm wondering if I'm getting too much flow through the heater core. While driving tonight, I turned the heater on, kept a constant speed, and the water temp didn't really budge - stayed at 135.
So - which strategy should I pursue? Open holes in my radiator shroud? Put a piece of plastic in front of the radiator? Put in a flow limiter - like a toyota heater core valve - on the heater core and start varying flow?