So your WP, all by itself (with fans off), is overcooling your engine? Almost sounds like your engine is not generating enough heat fast enough. How long does it take for your car to reach 190? A normal amount of time?Don't know how to tell that Noobz. Enough to rapidly cool the engine down as soon as the WP is turned on is all I can say. Maybe the heater control valve is open and letting water bypass the tstat, maybe the tstat is stuck open, I doubt that those little 1/4 steel lines that I plumbed into the top of the exhaust ports are doing it though. Guess the way to test is to pinch off the hose that goes to heater control valve and observe water movement through radiator before and after the pinch.....