Chip, yes we made sure all the air was bled out. I'm using Evans coolant .. maybe I should switch to something else. I'm also running the Whipple 3.3L w/ 17psi and 93 octane and flash tuned for the fans to come on earlier. I know hot jet coating my headers and borla would help the heat soak, but that wouldn't help the engine temps would it?
Evans coolant will make the temp gauge read hotter, not cooler from the info I have found. But it is not supposed to boil, they indicate you are good to 330deg:eek. You may want to call Evans. I know some folks that like it, and others that are skeptical. Basically they are saying the car will suffer no ill effects in performance, detonation, etc. I have not tried it, but seen others run it. I am in the too skeptical or too worried camp. It's an interesting product.
Below is from their FAQ on gauge readings
What will the COOLANT GAUGE read when using non-aqueous propylene glycol (NPG) coolant?
Answer: The normal operating range of standard coolant (ethylene glycol and water) is 160°F to 230°F with some cooling systems able to function reasonably well up to 240°F; although as this extreme temperature level is reached, the engine will almost always operate with ever less power and response until it boils over and stalls. At approximately 330°F the coolant warning light would normally light up; a cooling system operating with the more modern needle gauge would indicate higher coolant temperatures as they developed. As NPG contains no water, coolant temperatures can rise to higher levels without a negative impact on the performance of the engine. In fact, with NPG in many cases the activation of the coolant warning light represents a false warning as NPG works very well at 330°F. Gauges may show the needle at 330°F, a temperature probably located in the red, but again, no concern is warranted with NPG coolant.
http://www.evanscooling.com/main25.htm